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HP BASIC for OpenVMS User Manual

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1. 000 c eee eee 13 1 3 Stream Records s ovakk beaded Saeend opea chudede cued 13 2 File Organizations eese sses d60h0de cee en eee a booacege abe s 13 2 1 Terminal Format Files 0 0 0 0 0 cece eee 13 2 2 Sequential Files 0 0 ce ees 13 2 3 Relative Files 0 ce eee eee 13 2 4 Indexed Piles i i 6 state hh eee oie ees ded d s 13 2 5 Virtual Files 2id0c 4 chee bees Locen ee edeeene Seba s 13 3 Record Access and Record Context 000 eee ee 13 4 TO and Record Buffers 0 0 0 0 ce eens 13 5 Accessing the Contents of a Record 20 00005 13 5 1 MAP Statement 2 004 00 00 eden deena den ttig earn bas 13 5 2 MAP DYNAMIC and REMAP Statements 13 5 3 MOVE Statement 0 2 0 0 cc ee eee 13 6 File and Record Operations 0 0 00 c eee eee 13 6 1 Opening Files 0 0 cece eens 13 6 2 Creating Virtual Array Files 0 0 0 000 eee eee 13 6 3 Locating Records 0 0 cece eee eee 13 6 4 Reading Records sss 0 0 13 6 5 Writing Records 0 0 ccc eee eens 13 6 6 Deleting Records 0 0 cc cece eee 13 6 7 Updating Records 0 2 0 eee ee eee 13 6 8 Controlling Record Access 0000 cece eee eens 13 6 9 Gaining Access to Locked Records 005 13 6 10 Accessing Records by Record File Address 13 6 11 Transferring Data to Terminal Format Files 13 6 12 Res
2. 005 Programs Without Line Numbers apels reres tevore cas o eo Rese kos RES bh enD Continuation of Long Program Statements Identifying Program Units 0 00 eee BASIC Character Seti oes s eee el ete ewe twee eee Program Documentation 00 eee Declarations and Data Types 0 0 0 0 cece eee Implicit Data Typing 2 0 0 ce ees Explicit Data Typing 0 0 0 ccc ee eee Constants 24 ccee ceand renen dees ents ined oe tees d Variables 4 i ixctaw don dawh doi mb E ede FE EDA dyes ded Floating Point Variables 0 0 0 ee eee Integer Variables 0 0 0 cece eee Packed Decimal Variables 00 eee eee 3 1 3 2 3 2 3 4 3 4 3 6 3 7 3 10 3 11 3 11 3 12 3 13 3 13 3 15 3 15 3 17 4 1 4 1 4 2 4 3 4 3 4 4 4 5 4 6 4 8 4 8 4 10 4 10 4 10 4 11 4 7 4 4 7 5 4 7 6 4 8 4 9 4 10 String Variables Subscripted Variables Initialization of Variables Keywords and Reserved Words Operands Operators and Expressions 005 Assignment Statements 5 Simple Input and Output 5 1 5 1 1 5 1 1 1 5 1 1 2 5 1 1 3 5 1 2 5 1 2 1 5 1 2 2 5 2 5 2 1 5 2 2 5 3 5 3 1 5 3 2 6 Arrays 6 1 6 2 6 2 1 6 2 2 6 2 2 1 6 2 2 2 6 2 3 6 2 4 6 3 6 4 6 5 6 5 1 6 5 2 6 6 6 6 1 6 6 2 6 6 3 Program Input Providing Input Intera
3. 0 0 00 brig amaga oiy eee 21 2 21 2 2 Dictionary Path Names 000 ce eee eee 21 2 21 2 3 Dictionary Entities 2 0 2 eee eee eee 21 4 21 2 4 Dictionary Relationships 0 00 eee 21 4 21 2 5 Extracting CDD Repository Data Definitions 21 4 21 3 Using CDD Repository with BASIC 005 21 7 21 3 1 DEPENDENCY_DATA Qualifier 0004 21 7 21 3 2 Creating Relationships with Included Record Definitions 21 8 21 4 Creating Relationships for Referenced Dictionary Entities 21 10 21 5 Specifying a CDD History List Entry 0 21 11 21 6 CDD Repository Arrays 00 eens 21 12 21 7 CDD Repository Variants 0 0 eens 21 14 21 8 NAME FOR BASIC Clause 00 e eee eee ee ees 21 15 21 9 CDD Repository Data Types 0 0 eee 21 16 21 9 1 Character String Data Types 20 0 00 cee eee 21 21 21 9 2 Integer Data Types 0 0 ce cece eens 21 22 21 9 3 Floating Point Data Types 0 0 eee eee 21 25 21 9 4 Decimal String Data Types 0 0 cee eee 21 27 21 9 5 Other Data Types 0 0 0 cee ees 21 29 22 Using DECwindows Motif Bindings with BASIC 22 1 Overview of DECwindows Motif Concepts 4 22 1 22 2 Using DECwindows Motif Bindings with BASIC 22 1 22 3 DECwindows Motif Programming Examples Using BASIC 22 3 22 4 Special Considerations for Handling
4. 1CDD Repository specifies bit field length in bits HP BASIC specifies string length in bytes If the length in bits does not divide evenly into bytes HP BASIC signals the error Field lt fieldname gt from CDD Repository has bit offset or length continued on next page 21 20 Using CDD Repository with BASIC 21 9 1 Table 21 2 Cont Unsupported CDD Repository Data Types Data Type HP BASIC Translation UNSPECIFIED GROUP CDD Repository field name STRING STRING_VALUE length END GROUP VIRTUAL FIELD Ignored The following sections describe how HP BASIC translates CDD Repository data types Character String Data Types There are two CDD Repository character string data types TEXT and VARYING STRING The TEXT data type translates directly into the HP BASIC STRING data type VARYING STRING is not a supported HP BASIC data type therefore HP BASIC creates a group to contain the field The following example is a CDD Repository definition that contains both the TEXT and VARYING STRING data types and the translated HP BASIC RECORD statement Example 21 1 CDDL define record CDD top basic strings description is test basicstrings structure abc datatype is text size is 10 xyz datatype is varying string size is 16 end basicstrings structure end strings In the VARYING STRING data type the actual character string is preceded by a 16 bit count field Therefore HP BASIC creates a WORD variable to
5. 200 18 2 2 6 Rewinding a Tape 0 cee eee ee ees 18 2 2 7 Closing a Tape lt i5 0 8 6 lt o eaeoud open cbeareeeaneea 18 2 3 Device Specific I O to Disks 0 0000 eee eee 18 2 3 1 Assigning and Mounting a Disk 18 2 3 2 Opening a Disk File for Output 0 18 2 3 3 Opening a Disk File for Input 18 2 3 4 Writing Records to a Disk File 18 2 3 5 Reading Records from a Disk File 18 3 TO t Mailboxes 0 0 0 0 0c eens 18 4 Network VO resessie eww POS gel SA WR OE SR awe 18 4 1 Remote File Access 0 0 0 0 cece eee eae 18 4 2 Task to Task Communication 00000000 eee 18 4 3 Accessing a VAX Rdb VMS Database 19 Using BASIC in the Common Language Environment 19 1 Specifying Parameter Passing Mechanisms 19 1 1 Passing Parameters by Reference 055 19 1 2 Passing Parameters by Descriptor 0005 19 1 3 Passing Parameters by Value 0000 ee eee 19 1 4 HP BASIC Default Parameter Passing Mechanisms 19 1 5 Creating Local Copies 0 eee eee 19 1 6 Passing Arrays fo o oo sie OU OSES ON Ss ORO oe Oe 19 2 Calling External Routines 20 19 2 1 Determining the Type of Call 02220005 19 2 2 Declaring an External Routine and Its Arguments 19 2 3 Calling the Routine 0 0
6. IF directive contains a ELSE clause with no intervening THEN clause User Action Insert a THEN clause IF_IN_INC IF directive in INCLUDE directive needs END IF directive in same file Explanation ERROR A INCLUDE file contains a IF but no WEND IF User Action Supply a WEND IF for the INCLUDE file IF_NOTTER IF statement not terminated Explanation ERROR The program contains an if then else statement within a block for example a FOR NEXT SELECT CASE or WHILE block and the end of the block was reached before the if then else statement was terminated User Action Check program logic to be sure if then else statements are terminated with a line number or an END IF statement before the end of the block is reached ILLALLCLA illegal ALLOW clause lt clause gt Explanation ERROR The program contains an ALLOW clause on a GET statement and the file was not opened with the UNLOCK EXPLICIT clause User Action Either remove the ALLOW clause from the GET statement or use the UNLOCK EXPLICIT clause in the OPEN statement ILLARGBP2 illegal argument count for BASIC PLUS 2 Explanation INFORMATION The program contains a SUB DEF or EXTERNAL FUNCTION reference with more than 32 parameters This error is reported only when the FLAG BP2COMPATIBILITY qualifier is in effect User Action If the program must run under both HP BASIC and PDP 11 BASIC PLUS 2 the function must have 32 or fewer parameters ILLAR
7. LSE accepts keywords or tokens for all languages with LSE support However the specific tokens themselves are language defined For example you can expand the MAT token only when using HP BASIC Likewise LSE provides placeholders or prompt markers for all languages with LSE support However as with tokens the specific text or choices these markers call for are language defined For example you see the record declarations placeholder only when using HP BASIC Note Keywords such as TYPE VARIANT IF FOR and OPEN can be tokens as well as placeholders Therefore any time you are in LSE with the language set to HP BASIC you can type one of these words and press Ctrl E to expand the construct Remember that braces enclose required placeholders and brackets enclose optional placeholders Note that when you erase an optional placeholder LSE also deletes any associated text before and after that placeholder You can use the SHOW TOKEN and SHOW PLACEHOLDER commands to display a list of all HP BASIC tokens and placeholders or a particular token or placeholder For example LSE gt SHOW TOKEN IF lists the token IF LSE gt SHOW TOKEN lists all tokens Optional Programming Productivity Tools C 3 To copy the listed information into a separate file first enter the appropriate SHOW command to put the list into the SHOW buffer Next enter the following command LSE gt GOTO BUFFER SHOW LSE gt WRIT
8. 10 1 10 1 1 10 1 1 10 1 1 10 1 1 10 1 1 10 1 1 10 1 1 10 1 1 10 1 2 10 1 2 1 10 1 2 2 Yonik Statement Modifiers IF Modifier UNLESS Modifier FOR Modifier UNTIL Modifier WHILE Modifier Nesting Modifiers Loops FOR NEXT Loops WHILE NEXT Loops 0000s UNTIL NEXT LOOPS e 20d ene beadda wee taceeawesads Nesting Loops Unconditional Branching GOTO Statement Conditional Branching ON GOTO OTHERWISE Statement IF THEN ELSE Statement 00 00 0000 ee SELECT CASE Statement 0 0 0 0 e eee EXIT and ITERATE Statements 0 0 0 0 000 eee Executing Local Subroutines 0 00 0 GOSUB and RETURN Statements ON GOSUB OTHERWISE Statement Suspending and Halting Program Execution SLEEP Statement WAIT Statement STOP Statement END Statement ons Built In Functions Numeric Functions ABS Function INT and FIX Functions 0 000000 ee SIN COS and TAN Functions 0 SQR Function LOGIO Function 552d00 8 cease rn iess dee a OEKE EXP Function RND Function Data Conversion Functions 0 0000 eee eee ASCII Function CHR Function 9 1 9 2 9 2 9 2 9 2 9 2 9 3 9 3 9 3 9 6 9 7 9 8 9 8 9 9 9 9 9 10 9 12 9 14 9 16 9 16 9 17 9 18 9 19 9 19 9 20 9 20 vi
9. HP BASIC moves the decimal point two places to the left then rounds to units Note that when rounding numeric strings HP BASIC returns only part of the number If the integer expression is between 5001 and 15 000 the following rules apply e Ifthe integer expression is 10 000 HP BASIC truncates the number at the decimal point e Ifthe integer expression is greater than 10 000 10 000 plus n HP BASIC truncates the numeric string n places to the right of the decimal point For example if the integer expression is 10 001 10 000 plus 1 HP BASIC truncates the number starting one place to the right of the decimal point If the integer expression is 10 002 10 000 plus 2 HP BASIC truncates the number starting two places to the right of the decimal point and so on e Ifthe integer expression is less than 10 000 10 000 minus n HP BASIC truncates the numeric string n places to the left of the decimal point For example if the integer expression is 9999 10 000 minus 1 HP BASIC truncates the number starting one place to the left of the decimal point If the integer expression is 9998 10 000 minus 2 HP BASIC truncates starting two places to the left of the decimal point and so on The PLACE function returns a numeric string truncated or rounded according to an integer argument you supply The following example displays the use of the PLACE function with several different integer expression arguments number 123456 65
10. Overview of HP BASIC BASIC is a powerful structured programming language designed for novice and application programmers alike BASIC was originally developed for students with little or no programming experience Since then BASIC has become one of the most widely used programming languages and is available on almost every computer system The OpenVMS implementations of BASIC have evolved beyond the original design but still support all of the traditional features of the original language in addition to more recent programming techniques HP BASIC has become much more than a teaching tool and is used in a wide variety of sophisticated applications 1 1 Language Constructs Supported HP BASIC supports the following language constructs e Code without line numbers traditional line numbers are optional e Control structures such as SELECT CASE e Explicit variable declarations e Capabilities for handling dynamic strings e Adaptable file handling capabilities for terminal format files and the full range of RMS facilities e Global and local run time error handling with WHEN ERROR blocks e Compile time directives e A variety of data types including packed decimal user defined records and VAX and IEEE floating point data types e Extensive error checking with meaningful error messages e Thirty one character names for variables labels functions and subprograms Overview of HP BASIC 1 1 1 2 Advantages on OpenVMS HP BASIC us
11. Prints credit and debit characters immediately following the number BASIC prints CR for negative numbers and zero and DR for positive numbers Specifies that the next character is a literal not a formatting character Commas You can place a comma anywhere in a number field to the left of the decimal point or to the right of the field s first character A comma cannot start a format field BASIC prints a comma to the left of every third digit from the decimal point If there are fewer than four digits to the left of the decimal point BASIC omits the comma PRINT USING 10000 PRINT USING 759 PRINT USING SS 25694 3 PRINT USING 7259 PRINT USING 25239 END Formatting Output with the PRINT USING Statement 14 7 14 3 3 2 Output 10 000 759 25 694 30 7 259 25 239 00 Asierisk Fill Fields To print an asterisk before the first digit of a number you must start the field with two asterisks DECLARE STRING CONSTANT FM PRINT USING FM 1 2 PRINT USING FM 27 95 PRINT USING FM 107 PRINT USING FM 1007 5 END Output 1 20 27 95 107 00 1007 50 Note that the asterisks reserve two places as well as cause asterisk fill To specify a negative number in an asterisk fill field you must place a trailing minus sign in the field The trailing minus sign must be the last character in the format string DECLARE STRING CONSTANT FM
12. SUB example sub LONG X END SUB If you do not specify data types for parameters the default data type is determined by e The last specified parameter data type e An OPTION statement e An HP BASIC compilation qualifier for example REAL_SIZE DOUBLE e The system default The last specified parameter data type overrides all the other default data types the defaults specified in the OPTION statement override any compilation qualifiers and system defaults and so on When you know the length of a string or the dimensions of an array at compile time you can achieve optimum performance by passing them BY REF When you call programs written in other languages the practice of declaring subprograms and specifying the data types of parameters becomes more important because other languages might not use the HP BASIC default parameter passing mechanisms For more information about calling subprograms written in other languages see Chapter 19 12 6 Program Segmentation 12 3 Compiling Subprograms an HP BASIC source file can contain multiple program units When you compile such a file HP BASIC produces a single object file containing the code from all the program units You can then link this object file to create an executable image If the main program and subprograms are in separate source files you can compile them separately from the DCL level The following command causes HP BASIC to create MAIN OBJ SUB1 OBJ and SUB2 O
13. See Section 3 5 3 for an explanation of how the EXAMINE and the EVALUATE commands differ 3 5 2 Changing the Values of Variables To change the value of a variable use the DEPOSIT command as follows DBG gt DEPOSIT variable_name value The DEPOSIT command is like an assignment statement in BASIC In the following examples the DEPOSIT command assigns new values to different variables The debugger checks that the value assigned which may be a language expression is consistent with the data type and dimensional constraints of the variable Deposit a string value it must be enclosed in quotation marks or apostrophes DBG gt DEPOSIT PARTNUMBER WG 7619 3 84 Deposit an integer expression DBG gt DEPOSIT WIDTH CURRENT WIDTH 10 Deposit element 12 of an array of characters you cannot deposit an entire array aggregate with a single DEPOSIT command only an element DBG gt DEPOSIT C_ARRAY 12 K You can specify any kind of address expression not just a variable name with the DEPOSIT command as with the EXAMINE command You can override the defaults for typed and untyped locations if you want the data to be interpreted in some other data format 3 12 Using the OpenVMS Debugger with BASIC 3 5 3 Evaluating Expressions To evaluate a language expression use the EVALUATE command as follows DBG gt EVALUATE lang_exp The debugger recognizes the operators and expression syntax of the currently set language In the follo
14. User Action Specify a valid area style for the device ILLBYTCOU Illegal byte count for I O ERR 31 Explanation A PRINT or INPUT list invoked a function that closed an T O channel User Action Change the function so that it does not close the I O channel B 10 Run Time Messages ILLCNTCLA Illegal count clause ERR 290 Explanation In a graphics statement you specified a COUNT clause with a numeric value that exceeds the size of the array User Action Specify a numeric value that is less than or equal to the size of the array ILLCOLIND Illegal color index ERR 280 Explanation The index you specified is not supported by the device User Action Specify a valid color index The valid range of indices for the device is from 0 to the value retrieved by the ASK MAX COLOR statement ILLCOLMIX Illegal color mix ERR 291 Explanation The color mix value specified on the SET COLOR MIX statement is outside the range of 0 to 1 User Action Specify a value from 0 to 1 ILLDEVID Illegal device identification number ERR 266 Explanation The device identification number is beyond the valid range of 0 through 255 User Action Specify a device identification number between 0 and 255 ILLDEVNAM Illegal device name in OPEN ERR 292 Explanation An explicit or implicit OPEN FOR GRAPHICS statement contains an illegal device name for the device type being used Possible causes include e Specifying a device that do
15. You can also assign values to variables with the DATA and READ statements however this method requires that you know all input data values while you are coding your program The INPUT LINPUT and INPUT LINE statements all assign values in the context of data being read into the program These statements are discussed in Chapter 5 4 14 BASIC Concepts and Elements 5 Simple Input and Output This chapter explains how to use BASIC statements to move data to and from your program 5 1 Program Input BASIC programs receive data in the following ways e You can enter data interactively while the program runs You do this with the INPUT INPUT LINE and LINPUT statements e If you know all the information your program will require you can enter it as you write the program You do this with the READ DATA and RESTORE statements or you can name constants with the known values e You can read data from files outside the program You do this with the INPUT INPUT LINE and LINPUT statements The following sections describe how to use these statements in detail 5 1 1 Providing Input Interactively The INPUT INPUT LINE and LINPUT statements prompt a user for data while the program runs 5 1 1 1 INPUT Statement The INPUT statement interactively prompts the user for data You can use the optional prompt string to clarify the input request by specifying the type and number of data elements required by the program This is
16. 20 OPEN MTO FILE DAT FOR INPUT AS FILE 4 amp SEQUENTIAL FIXED MAP XXX ACCESS READ NA MES GET 4 UNTIL NA ME JONES PRINT NA MES LIVES AT address CLOSE 4 END Rewinding a Tape With the RESTORE statement you can rewind the tape to the start of the currently open file For example OPEN MTO FTF DAT FOR INPUT AS FILE 2 ACCESS READ GET 2 RESTORE 2 GET 2 You cannot rewind past the beginning of the currently open file Closing a File The CLOSE statement ends I O to the file The following statement ends input and output to the file open on channel 6 CLOSE 6 If you opened the file with ACCESS READ CLOSE has no further effect If you opened the file without specifying ACCESS READ and the tape is not write locked that is if the plastic write ring is in place HP BASIC does the following 18 6 Advanced File Input and Output e Writes the file trailer labels and two end of file marks following the last record e Backspaces over the last end of file mark HP BASIC does not rewind the tape 18 2 Device Specific I O 18 2 1 18 2 2 18 2 2 1 Device specific I O lets you perform I O directly to a device The following sections describe device specific I O to unit record devices tapes and disks Device Specific I O to Unit Record Devices You perform device specific I O to unit record devices by using only the device name in the OPEN statement file specification You shoul
17. ANSLINNUM ANSI line numbers must begin in column 1 Explanation ERROR A program compiled with the ANSI_STANDARD qualifier contains a line number preceded by one or more spaces or tabs User Action Remove any spaces and tabs that precede the line number ANSREQREA ANSI requires REAL default type Explanation ERROR The ANSI_STANDARD qualifier conflicts with the TYPE_DEFAULT qualifier User Action Do not specify a default data type other than REAL REAL is the default A 4 Compile Time Error Messages ANSREQSCA ANSI requires SCALE 0 Explanation ERROR The ANSI_STANDARD qualifier conflicts with the SCALE qualifier User Action Do not specify a scale factor ANSREQSET ANSI requires SETUP Explanation ERROR The ANSI_STANDARD qualifier conflicts with the NOSETUP qualifier User Action Do not specify NOSETUP ANYDIMNOT dimension checking not allowed on ANY Explanation ERROR Both a data type of ANY and a DIM clause were specified in an EXTERNAL statement User Action Remove the DIM clause from the EXTERNAL statement ANY implies either scalar or array ANYNOTALL ANY not allowed on EXTERNAL PICTURE Explanation ERROR An attempt was made to specify the ANY keyword on an EXTERNAL PICTURE declaration This is not allowed because the ANY data type should be used for calling non BASIC procedures only User Action Remove the ANY keyword from the EXTERNAL PICTURE declaration APPMISNUM appen
18. An operand contains a value An operand can be a scalar subscripted variable named constant literal and so on An operator specifies a procedure to be carried out by one or more operands An expression consists of operands separated by operators The following are types of operators Arithmetic String Relational Logical When combined with operands these operators can produce e Numeric expressions e String expressions BASIC Concepts and Elements 4 13 e Conditional expressions For more information about operands operators and expressions see the HP BASIC for OpenVMS Reference Manual 4 10 Assignment Statements The following statements assign values to variables e LET e INPUT e LINPUT e INPUT LINE LET and INPUT statements allow you to assign values to any type of variable while LINPUT and INPUT LINE allow you to assign values to string variables For example LET A 1 25 LET is an optional keyword You can assign a value to more than one variable at a time although this is not reeommended Instead use a separate assignment statement each time you assign a value to a variable Whenever you assign a value to a numeric variable BASIC converts the value to the data type of the variable If you assign a floating point value to an integer variable BASIC truncates the value at the decimal point If you assign an integer value to a floating point variable BASIC converts the value to floating point format
19. CASE CASE CASE Ee 2 3s 4 Is 6 Ts 8 TOs 10 Tl FIRST NAME LAST NAME STREET NUMBER STREET CITY STATE ZIP WAGE CLASS DATE OF REVIEW SALARY YTD TAX YTD CHANGE NUMBER NUMBER SELECT NUMBER 1 INPUT 2 INPUT 3 INPUT 4 INPUT 5 INPUT 6 FIRST NAME first_name LAST NAME last_name STREET NUMBER street_number STREET street CITY city INPUT STATE state CASE CASE CASE CASE CASE CASE END S 1 INPUT 8 INPUT 9 INPUT 10 INPUT 11 INPUT ELSE PRINT ELECT ZIP CODE zip WAGE CLASS wage_class DATE OF REVIEW date of review SALARY YTD salary ytd TAX YTD tax_ytd Invalid choice String Handling 11 19 NEXT END Output Changes please type YES or NO YES FIRST NAME LAST NAME STREET NUMBER STREET CITY STATE ZIP WAGE CLASS 9 DATE OF REVIEW 10 SALARY YTD 11 TAX YTD CHANGE NUMBER 10 SALARY YTD 14 277 08 Changes please type YES or NO YES CHANGE NUMBER 11 TAX YTD 998 32 Changes please type YES or NO NO See Chapter 7 and the HP BASIC for OpenVMS Reference Manual for more information about the MAP statement OADM BUNE 11 20 String Handling 12 Program Segmentation This chapter describes how to e Declare HP BASIC subprograms e Write HP BASIC subprograms Program segmentation is the process of dividing a program into small man
20. MAT PRINT B PRINT PRINT ARRAY C MAT PRINT C Output ARRAY A 0 ooonoocncoocoo oooocjoo ocoo oooocoococoo ooooc jcoo o coo ooooc joococoo ooooococococococoe oooooccoceoo oooooccocooo wa K oocoooocornof PE GOO0OOGGOGOOGO G SCCDODCCOOFPCCON FW OGOGoOGGOOOGOOOGG Re oOooo0oo0oo0ooro oOo oO ooooc jcoroqoqjooo oooorcjoooo ooorcj ocooocoo oorocoocoococe oOorooocoocococce eooo OO Arrays 6 13 6 6 2 MAT READ Statement The MAT READ statement assigns values from DATA statements to array elements Subscripts define either the dimensions of the array being created or the new dimensions of an existing array subscripts are optional in MAT READ statements If you do not provide enough data in DATA statements to fill the specified array BASIC leaves the remaining array elements unchanged If you provide more data values than there are array elements BASIC assigns enough values to fill the array and leaves the DATA pointer at the next value In the following example BASIC fills matrix B with the first four DATA items fills matrix C with the next four DATA values and leaves the DATA pointer at the ninth value in the DATA list MAT READ B 2 2 MAT READ C 2 2 PRINT PRINT MATRIX B PRINT PRINT MAT PRINT B PRINT PRINT MATRIX C PRINT PRINT MAT PRINT C DATA 1 2 3 4 5 6 7 8 9 10 END Output MATRIX B 1 2 3 4 MATRIX C 5 6 7 8 6 6 3 MAT INPUT Statemen
21. Output 00001 23 00012 34 00123 45 01234 56 12345 67 When you specify zero fill you cannot specify asterisk fill or floating dollar sign format for the same field Blank lf Zero Fields To print a blank field for values which round to zero you must start the numeric field with a percent sign enclosed in angle brackets lt gt In the following example PRINT USING displays spaces in each reserved position for the second and third items in the list The value of the second item is zero while the value of the third item becomes zero when rounded to fit the numeric field DECLARE STRING CONSTANT FM lt o gt PRINT USING FM 1000 0 001 5000 Formatting Output with the PRINT USING Statement 14 11 Output 1000 00 5000 00 14 3 3 8 Debits and Credits You can have BASIC use credit and debit notation to differentiate positive and negative numbers To do this you place the characters lt CD gt Credit Debit at the end of the numeric format string This causes BASIC to print CR Credit Record after negative numbers and DR Debit Record after positive numbers and zero DECLARE STRING CONSTANT FM SS lt cd gt PRINT USING FM 552 35 200 5 Output 552 35CR 200 00DR 5 00CR You cannot use a trailing minus sign and Credit Debit formatting in the same numeric field Using the Credit Debit formatting character causes the value to be printed with a leading space 14 4 Printing Strings
22. PRINT USING FM 27 95 PRINT USING FM 107 PRINT USING FM 1007 5 END Output 27 95 107 00 1007 50 If you try to print a negative number in an asterisk fill field that does not include a trailing minus sign BASIC signals PRINT USING format error ERR 116 You cannot specify both asterisk fill and zero fill for the same numeric field 14 8 Formatting Output with the PRINT USING Statement 14 3 3 3 14 3 3 4 Currency Symbols To print a currency symbol before the first digit of a number you must start the field with two dollar signs If the data contains both positive and negative numbers you must include a trailing minus sign DECLARE STRING CONSTANT FM SS PRINT USING FM 77 44 PRINT USING FM 304 55 PRINT USING FM 2211 42 PRINT USING FM 125 6 PRINT USING FM 127 82 END Output 77 44 304 55 2211 42 125 60 127 82 Note that the dollar signs reserve places for the currency symbol and only one digit the dollar sign is always printed Hence the warning indicator when the third PRINT USING statement executes Contrast this with the asterisk fill field where BASIC prints asterisks only when there are leading spaces By default the currency symbol is a dollar sign On OpenVMS systems you can change the currency symbol radix point and digit separator by assigning the characters you want to the logical names SYS CURRENCY SYS RADIX_ POINT and SYS DIGIT_SEP respect
23. With the PRINT USING statement you can specify the following aspects of string format e The number of characters e Left justified format e Right justified format e Centered format e Extended field format Table 14 2 summarizes the format characters and their effects 14 12 Formatting Output with the PRINT USING Statement Table 14 2 Format Characters for String Fields Character Effect on Format Single quotation mark Starts the string field and reserves a place for one character L upper or lowercase Left justifies the string and reserves a place for one character R upper or lowercase Right justifies the string and reserves a place for one character C upper or lowercase Centers the string in the field and reserves a place for one character E upper or lowercase Left justifies the string expands the field as necessary to print the entire string and reserves a place for one character Two backslashes Reserves n 2 character positions where n is the number of spaces between the two backslashes PRINT USING left justifies the string in this field This formatting character is included for compatibility with BASIC PLUS It is recommended that you not use this type of field for new program development Exclamation point Creates a 1 character field The exclamation point both starts and ends the field This formatting character is included for compatibility with BASIC PLUS It is recomme
24. amp SEQUENTIAL STREAM The following example creates a relative file and associates it with a static record buffer The MAP statement defines the record buffer s total size and the data types of its variables When the program is compiled BASIC allocates space in the record buffer for one integer one 16 byte string and one double precision floating point number The record size is the total of these fields or 28 bytes All subsequent record operations use this static buffer for I O to the file MAP Inv_item LONG Part_number amp STRING Inv_name 16 amp DOUBLE Unit price OPEN INVENTORY DAT FOR OUTPUT AS FILE 1 amp ORGANIZATION RELATIVE FIXED ACCESS MODIFY amp ALLOW READ MAP Inv_item The following OPEN statement opens a sequential file for reading only ACCESS READ Because the OPEN statement does not contain a MAP clause a record buffer is created This record buffer is 100 bytes long OPEN CASE DAT AS FILE 1 amp ORGANIZATION SEQUENTIAL VARIABLE amp ACCESS READ amp RECORDSIZE 100 When you do not specify a MAP statement your program must use MOVE TO and MOVE FROM statements to move data between the record buffer and a list of variables 13 12 File Input and Output The OPEN statement for indexed files must have a MAP clause Moreover if you are creating an indexed file a PRIMARY KEY clause is required You can create a segmented index key containing more than one string variable b
25. nes 19 3 Calling HP BASIC Subprograms from Other Languages 19 4 Calling System Routines 0 0 00 cece eens 19 4 1 OpenVMS Run Time Library Routines 19 4 2 System Service Routines 0 000 e eee eens 19 4 3 System Routine Arguments 0 0 0 0 eee eee 19 4 4 Including Symbolic Definitions 200 19 4 5 Condition Values s se aces epa e meteta eee ees 19 5 Examples of Calling System Routines 04 19 6 OpenVMS Calling Standard 0 0 19 7 Additional Information 0 0 0 cee eee 18 7 18 7 18 8 18 8 18 9 18 9 18 10 18 10 18 10 18 11 18 11 18 11 18 11 18 12 18 13 18 15 18 15 18 16 18 18 19 1 19 2 19 2 19 2 19 3 19 4 19 5 19 5 19 6 19 6 19 7 19 8 19 10 19 11 19 11 19 12 19 17 19 19 19 19 19 22 19 23 xiii 20 Libraries and Shareable Images 20 1 Overview of Libraries 0 0 0 ee eee 20 1 20 2 System Supplied Libraries 0 0 0 ees 20 2 20 3 Creating User Supplied Object Module Libraries 20 3 20 3 1 Accessing User Supplied Object Module Libraries 20 3 20 4 Shareable Images 0 cece eee eee nee 20 4 20 4 1 Accessing Shareable Images 00 00 ee eee 20 5 21 Using CDD Repository with BASIC 21 1 Overview of CDD Repository 0 0 cee 21 1 21 2 CDD Repository Concepts 000 ce ees 21 1 21 2 1 Dictionary Formats
26. or to the error handler of the calling program in the case of a separately compiled subprogram An error handler in the DEF function does not permanently override an error handler in the main program HP BASIC saves the error handler in the main program when you transfer into a DEF and restores it when you return The ON ERROR GOTO statement is usually placed before any other executable statements The following example clears end of file errors and passes all other errors back to the HP BASIC default error handling procedures 5 ON ERROR GOTO Error handler Error_handler Trap end of file on device IF ERR 11 THEN RESUME 1000 ELSE ON ERROR GO BACK END IF The ON ERROR GOTO statement remains in effect after your program successfully handles an error When the system signals another error control once again transfers to the specified error handler Every ON ERROR error handler must end with one of the following statements e RESUME target e ON ERROR GOTO 0 e ON ERROR GO BACK 15 22 Handling Run Time Errors If none of these statements is present the HP BASIC error handler aborts your program with the fatal error Error trap needs RESUME as soon as an END END SUB END DEF END FUNCTION END PROGRAM or END PICTURE statement is encountered The RESUME statement like the RETRY and CONTINUE statements clears the error condition You can resume execution at any line number or label that is in the same module a
27. 19 1 3 e By descriptor BY DESC e By value BY VALUE The following sections outline each of these parameter passing mechanisms in more detail Passing Parameters by Reference When you pass a parameter by reference HP BASIC passes the address at which the actual parameter value is stored In other words your routine has access to the parameter s storage address therefore you can manipulate and change the value of this parameter Any changes that you make to the value of the parameter in your routine are reflected in the calling routine as well Passing Parameters by Descriptor A descriptor is a data structure that contains the address of a parameter along with other information such as the parameter s data type and size When you pass a parameter by descriptor the HP BASIC compiler passes the address of a descriptor to the called routine You usually use descriptors to pass parameters that have unknown lengths such as the following e Character strings e Arrays e Compound data structures Like parameters passed by reference any change made to the value of a parameter passed by descriptor is reflected in the calling routine Passing Parameters by Value When you pass a parameter by value you pass a copy of the parameter value to the routine instead of passing its address Because the actual value of the parameter is passed the routine does not have access to the storage location of the parameter therefore any chang
28. 305 3 sees pha yts Se are BE EGA ae eae 11 6 2 POS Punction cso chad eee eed ee Onde Eee de he pie ae eer 11 6 3 SEG Function s 5 4004 0e 4a eed brea apedieeaeewds 11 6 4 MID Function 0 000 11 6 5 STRING Function 000 e eee eee eee rart 11 6 6 SPACES Function 0 0 ccc eee ee ee ce eee eens 11 6 7 TRIMS Function e 4 64 60 4 40k 6 ba Se bao OMe eae On De gees 11 6 8 EDIT Function 0 00 c eee cee eee eee eae 11 7 Manipulating String Data with Multiple Maps 10 7 10 8 10 8 10 9 10 10 10 11 10 11 10 13 10 14 10 14 10 14 10 15 10 15 10 16 10 16 10 17 10 18 10 18 10 20 11 1 11 2 11 3 11 4 11 5 11 5 11 6 11 7 11 8 11 9 11 9 11 10 11 12 11 14 11 15 11 16 11 16 11 16 11 18 12 Program Segmentation 12 1 HP BASIC Subprograms 0 00 12 1 1 SUB Subprograms 0 0 0 12 1 2 FUNCTION Subprograms 0 000 eee 12 2 Declaring Subprograms and Parameters 12 3 Compiling Subprograms 0 00 eee 12 4 Invoking Subprograms 0 c eee eee eee 12 4 1 Invoking SUB Subprograms 00 ce eens 12 4 2 Invoking FUNCTION Subprograms 4 12 5 Returning Program Status 0 eee 13 File Input and Output 13 1 Record Formats 0 0 0 0 eee ene 13 1 1 Fixed Length Records 0 cece eee ee eee 13 1 2 Variable Length Records
29. 7 2 Data Types At its most fundamental level a data type is a format for information storage All information is stored in the computer as bit patterns groups of ones and zeros Data types specify how the computer should interpret these patterns HP BASIC programs allow five general data types integer floating point string packed decimal and record Each data type is suited for a particular type of task For example integers are useful for numeric computations involving whole numbers strings provide a way to manipulate alphanumeric Data Definition 7 1 characters and packed decimal data is useful for manipulating numeric values that require precise representation For more information about HP BASIC data types see the HP BASIC for OpenVMS Reference Manual 7 3 Setting the Default Data Type and Size There are two ways to set the default data type and size for your program e With the OPTION statement e With the following qualifiers TYPE_DEFAULT AINTEGER_SIZE REAL_SIZE DECIMAL_SIZE The OPTION statement can override the defaults set with qualifiers For example the following statement sets the default integer type to be LONG OPTION SIZE INTEGER LONG You can have more than one OPTION statement in a program module however OPTION statements can be preceded only by a SUB FUNCTION REM or another OPTION statement Note that the OPTION statement can also specify the following e Integer and packe
30. A resequenced program contains a IF THEN ELSE END amp IF directive User Action Remove the IF THEN ELSE END IF directive RESABOSYN RESEQUENCE aborted due to syntax error Explanation ERROR A RESEQUENCE operation was terminated because the program was not syntactically correct User Action Correct the syntax error and retry the RESEQUENCE operation RESATTINC result attributes inconsistent with prior declaration Explanation ERROR An external or DEF function declaration specifies a data type for the function s result which is different from the data type the DEF or FUNCTION statement specifies User Action Change the specified data type in either the declaration or the DEF or FUNCTION statement so that the data types agree RESINCLIN RESEQUENCE cannot be used if INCLUDE files reference line numbers Explanation ERROR The current program references an INCLUDE file that contains line number references for example GOTO User Action Remove the INCLUDE directive HP BASIC cannot resequence lines in an INCLUDE file RESLINGTR RESEQUENCE cannot generate line numbers greater than 32 767 Explanation ERROR The RESEQUENCE command specified an interval or starting point that would have created a line number greater than 32 767 User Action Reduce the interval or the starting point A 76 Compile Time Error Messages RESNOTWHE RESUME not allowed in WHEN block or handler Explanation ERROR A
31. CDD CDDSTOP BASIC FUNNYINTEGERS Cl Test of quadword and octaword integer data types Cl RECORD BASICINT UNSPECIFIED Cl GROUP MY BYTE SIGNED BYTE Cl BYTE BYTE VALUE Cl END GROUP Cl LONG MY LONG SIGNED LONGWORD Cl END RECORD SBASIC I CDDATTSCA CDD specifies SCALE for BASICINT MY BYTE Not supported SBASIC E CDDATTBAS CDD attributes for BASICINT MY LONG are other than base 10 21 9 3 At compilation time HP BASIC also signals these warning errors for each reference to fields that are not base 10 or that have a SCALE Floating Point Data Types CDD Repository supports F_floating D_floating and G_floating data types These correspond to the BASIC SINGLE DOUBLE and GFLOAT data types respectively As with fixed point data types CDD Repository also allows the specification of scale and base for floating point data types If a CDD Repository data definition contains a floating point field that specifies a SCALE or BASE HP BASIC signals the informational message CDD Repository specifies SCALE for lt name gt Not supported or the error message CDD Repository attributes for lt name gt are other than base 10 For example 1 HP BASIC does not support the H_floating or HFLOAT data type Using CDD Repository with BASIC 21 25 CDDL Definition define record floats description is Test of floating point data types basicfloat structure my single datatype is f floating scale 3 my double
32. Compiler Directives 16 1 e Directives cannot appear within a quoted string e Directives cannot follow an END END SUB or END FUNCTION statement 16 2 Controlling the Compilation Listing 16 2 1 The following compiler listing directives let you control the content and appearance of the compilation listing e TITLE places a title string on the first line of the listing header e SBTTL places a subtitle string on the second line of the listing header e IDENT places an identification string on the second line of the listing header and within the object module e PAGE causes BASIC to skip to top of form in the output listing e NOLIST causes BASIC to stop accumulating information for the output listing e LIST causes BASIC to resume accumulating information for the output listing e NOCROSS causes BASIC to stop accumulating cross reference information for the output listing e CROSS causes BASIC to resume accumulating cross reference information for the output listing These directives are described in the following sections The listing control directives have no effect if no source program listing is being produced Similarly the CROSS and NOCROSS directives have no effect if no cross reference listing is being produced However the IDENT directive places the specified text in the object module whether or not a listing is produced TITLE and SBTTL Directives The TITLE directive lets you specify a line
33. Date of purchase 15 JUNE 1985 Requisition number 4167C Department name AUTOMOTIVE Date of purchase 6 JANUARY 1985 Requisition number 2522A Department name SPORTING GOODS Date of purchase 25 FEBRUARY 1985 13 20 File Input and Output 13 6 6 13 6 7 BAS F DUPKEYDET Duplicate key detected BAS I ON CHAFIL on channel 2 for file USERSSDISK MAGNUS INFO DAT 8 at user PC 0017E593 BAS O FROLINMOD from line 30 in module DUPLICATES RMS F DUP duplicate key detected DUP not set Deleting Records The DELETE statement removes a record from a file that was opened with ACCESS MODIFY After you have deleted a record you cannot retrieve it DELETE works with relative and indexed files only A successful FIND or GET operation must precede the DELETE operation These operations make the target record available for deletion In the following example the FIND statement locates record 67 in a relative file and the DELETE statement removes this record from the file Because the cell itself is not deleted you can use the PUT statement to write a record into that cell after deleting its contents FIND 1 RECORD 67 DELETE 1 Note There is no current record after a deletion The next record pointer is unchanged Updating Records The UPDATE statement writes a new record at the location indicated by the current record pointer UPDATE is valid on RMS sequential relative and indexed files UPDATE operates on
34. ERROR You specified an array with less than four elements This statement requires an array with at least four elements in it User Action Supply an array declared as having at least 4 elements ARRNAMREQ array names only allowed Explanation ERROR The type of variable name required must be an array name User Action Change the variable name to an array name ARRNOTALL array lt name gt not allowed in DEF declaration Explanation ERROR The parameter list for a DEF function definition contained an entire array User Action Remove the array specification Passing an entire array as a parameter to a DEF function is not allowed ARRTOOBIG named array lt array name gt is too large Explanation ERROR An array must occupy fewer than 216 1 bytes of storage User Action Reduce the size of the array If the array is within a record the maximum size of the array is 65 535 bytes A 6 Compile Time Error Messages ATROVRVAR attributes of overlaid variable lt name gt don t match Explanation ERROR A variable name appears in more than one overlaid MAP however the attributes specified for the variable are inconsistent User Action If the same variable name appears in multiple overlaid MAPs the attributes for example data type must be identical ATRPRIREF attributes of prior reference to lt name gt don t match Explanation WARNING A variable or array is referenced before the MAP that dec
35. MSG 32 MAP FIL NAMES 32 RESERVATIONS 64 OPEN SYS NET FOR INPUT AS FILE 1 SEQUENTIAL amp MAP SJK OPEN RESER DAT FOR INPUT AS FILE 2 amp INDEXED FIXED PRIMARY NAMES MAP FIL GET 18 MSG NAME CONFIRMED WHEN ERROR IN 100 FIND 2 KEY 0 EQ MSG USE IF ERR 153 THEN MSG ERROR IN NAME ELSE EXIT HANDLER END IF END WHEN PUT 1 CLOSE 2 1 END The task to task communication ends when the files are closed See the DECnet for OpenVMS Networking Manual and the HP OpenVMS System Manager s Manual for more information Advanced File Input and Output 18 17 18 4 3 Accessing a VAX Rdb VMS Database If you have purchased a VAX Rdb VMS development license you can store and access data in a VAX Rdb VMS database from a HP BASIC program To do this you embed RDO statements in your HP BASIC program Each line of an RDO statement must be preceded by the Rdb VMS statement flag amp RDB amp HP BASIC line numbers cannot be included in any RDO statement line You then precompile your program with the Rdb VMS precompiler The precompiler translates the RDO statements into BASIC statements that make direct calls to Rdb VMS 18 18 Advanced File Input and Output 19 Using BASIC in the Common Language Environment This chapter shows you how to call the following e External routines written in other OpenVMS languages e OpenVMS Run Time Library routines e OpenVMS system services The terms rou
36. None The maximum string length for virtual arrays is 512 Compile Time Error Messages A 81 STRLITREQ string literal required for compiler directive Explanation ERROR A quoted string is missing in a compiler directive that requires one for example IDENT User Action Supply a string literal for the compiler directive STROUTRAN string is too large Explanation ERROR A string exceeds the maximum allowable length The maximum length is 65 535 characters User Action Reduce the length of the string STRRECFIE string record element may not be FIELDed Explanation ERROR A FIELD statement contains a string record element as the fielded variable User Action Replace the string record element with a dynamic string Fielded variables must be dynamic STRRECFOR stream format must have sequential organization Explanation ERROR A file was opened using STREAM as a record format but the specified organization was not SEQUENTIAL User Action Change the OPEN statement so that it specifies ORGANIZATION SEQUENTIAL STRVAREXP string variable expected Explanation ERROR A CHANGE statement specifies a numeric variable User Action Supply a string variable the CHANGE statement changes a string variable to a numeric array and vice versa STRVARREQ string variable required Explanation ERROR A statement references a numeric variable instead of a string variable for example LINPUT A User Action Suppl
37. Opening a Tape File for Output To create and open the magnetic tape for output you use the OPEN statement The following statement opens tape drive MT1 for writing It is important to use the SEQUENTIAL VARIABLE clause unless the records are fixed In contrast to ANSI tape processing RMS does not write record length headers or variable length records to foreign tapes If you specify SEQUENTIAL VARIABLE you should have some way to determine where records begin and end OPEN MT1 FOR OUTPUT AS FILE 1 amp ORGANIZATION SEQUENTIAL VARIABLE Opening a Tape File for Input To access a tape with existing data you also use the OPEN statement For example the following statement opens the tape unit MT2 OPEN MT2 AS FILE 2 Depending on how you access records there are two ways to open a foreign magnetic tape If your program uses dynamic buffering and MOVE statements open the file with no RECORDSIZE clause RMS will provide the correct buffer size for HP BASIC Do not specify a BLOCKSIZE value or ORGANIZATION clause with the OPEN statement If your program uses MAP and REMAP statements but you do not know how long the records are specify a MAP that is as large as the value you specified for the BLOCKSIZE qualifier when mounting the tape Do not specify a BLOCKSIZE value or ORGANIZATION clause with the OPEN statement When processing records each GET operation will read one physical record whose size is returned in RECOUNT
38. Qualifiers 5 3 ea0 haa note ea nd SHS Chae Re Re eae S s StAteMENts a ga aed oe ea a ee ee ee xix 3 Using the OpenVMS Debugger with BASIC 3 1 3 2 3 3 3 3 1 3 3 2 3 4 3 4 1 3 4 2 Overview of the Debugger 0 2 0 0 cece eee eee Compiling and Linking to Prepare for Debugging Viewing Your Source Code 0 0 eee Noscreen Mode 00 0 c ee eee eee eens Screen Mode 000 eee eee eee eens Controlling and Monitoring Program Execution Starting and Resuming Program Execution Determining the Current Location of the Program Counter ccc ices het sheetdaeead eho Seeded eee ean Suspending Program Execution 00 005 Tracing Program Execution 0000 e eee Monitoring Changes in Variables Examining and Manipulating Data Displaying the Values of Variables Changing the Values of Variables Evaluating Expressions 0 000 e eee eee Stepping Into BASIC Routines 000 Controlling Symbol References 0004 Sample Debugging Session 0 0 00 ccc eee eee eee Hints for Using the OpenVMS Debugger Part Il HP BASIC Programming Concepts 4 BASIC Concepts and Elements 4 1 4 1 1 4 1 2 4 1 3 4 1 4 4 2 4 3 4 4 4 5 Tune Numbers iisccaa cede edi aeeadeebe aren eeebee ena Programs with Line Numbers
39. REAL R IF R lt 0 THEN Sphere volume 0 0 ELSE Sphere volume 4 3 PI R 3 END IF END FUNCTION The following example declares the FUNCTION subprogram and invokes it PROGRAM call sphere EXTERNAL REAL FUNCTION SPHERE VOLUME REAL PRINT SPHERE VOLUME 5 925 END PROGRAM Note that this module is compiled separately from the FUNCTION subprogram You can link these modules together to run the program from DCL level 12 2 Declaring Subprograms and Parameters You declare a subprogram by naming it in an EXTERNAL statement in the calling program You may also declare the data type of each parameter If the subprogram is a function the EXTERNAL statement also lets you specify the data type of the returned value The following statements are subprogram declarations using the EXTERNAL statement EXTERNAL SUB my_sub LONG STRING EXTERNAL GFLOAT FUNCTION my func GFLOAT LONG GFLOAT EXTERNAL REAL FUNCTION determinant LONG DIM 12 4 Program Segmentation Note that the parameter lists contain only data type and dimension information they cannot contain any format or actual parameters When the external procedure is invoked HP BASIC ensures that the actual parameter data type matches the data type specified in the EXTERNAL declaration However HP BASIC does not check to make sure that the parameters declared in the EXTERNAL statement match those in the external routine You must ensure that these parameters mat
40. Second test1 An array element is assigned to a single instance Second test1 Array of test1 2 And vice versa Array of testl 2 Second_testl Further you can assign values from single RECORD instances to groups contained in other instances In the following example Array_of_test1 and First_test1 do not have the same form because Array_of_test1 is an array of RECORD Test1 and First_test1 is a single instance of RECORD Test1 Therefore First_test1 and Array_of_test1 cannot be assigned to one another 8 12 Creating and Using Data Structures A single instance is assigned to one group Array of testl 3 Group_1 2 First_testl An array element is assigned a value from a group contained in another array instance Array_of test3 5 Array of test1 3 Group_1 3 The examples shown in this chapter explain the mechanics of using data structures See Chapter 12 for more information about using data structures as parameters See Chapter 13 for more information about using data structures for file input and output Creating and Using Data Structures 8 13 9 Program Control This chapter describes the HP BASIC control statements HP BASIC normally executes statements sequentially Control statements let you change this sequence of execution HP BASIC control statements can alter the sequence of program execution at several levels e Statement modifiers control the execution of a single statement e Loops or decisi
41. Soc_sec_number Social security END IF a NEXT Index FOR Index 0 TO 10 PRINT PRINT Employee number is Emp array Index Emp number PRINT First name is Emp _array Index First_name PRINT Last name is Emp _array Index Last_name PRINT Social security is Emp array Index Soc_sec_number NEXT Index END Creating and Using Data Structures 8 3 You can have a RECORD that contains an array When you declare arrays HP BASIC allows you to specify both lower and upper bounds RECORD Grade_record STRING Student_name 30 INTEGER Quiz_scores 1 TO 10 Array to hold ten quiz grades END RECORD Declarations DECLARE Grade_record Student_grades 5 The Student_grades array holds information on six students 0 through 5 each of whom has ten quiz grades 1 through 10 DECLARE INTEGER I J Program logic starts here FOR I 0 T0 5 This loop executes once for each student PRINT INPUT Student name Student_grades 1I Student_name FOR J 1 TO 10 This loop executes ten times for each student PRINT Score for quiz number J INPUT Student_grades I Quiz scores J NEXT J NEXT I FOR I 0 T0 5 PRINT PRINT Student name Student_grades I Student_name FOR J 1 TO 10 PRINT Score for quiz number J PRINT Student_grades 1I Quiz_scores J NEXT J NEXT I END Because any reference to a component of a RECORD instance must begin with the name of the RECORD i
42. TSLFE THEN PRINT ERTS ERR CONTINUE ELSE EXIT HANDLER END IF END HANDLER 15 14 Handling Run Time Errors 15 2 5 5 Determining OpenVMS Error Information HP BASIC provides a built in function VMSSTATUS that returns the originally signaled error before it is translated to a BASIC error For example for the BASIC error End of file on device ERR 11 the VMSSTATUS function returns RMS EOF RMS end of file This function is useful when the error is NOTBASIC ERR 194 When there is no error pending VMSSTATUS is undefined The value returned by this function is the actual signaled error value If non BASIC errors are being handled the VMSSTATUS function might be the only way to find out which error caused the exception The following example shows a program that performs file I O The first WHEN ERROR block traps any errors that occur while the program is opening the file or requesting user input The detached handler for this block checks the value of VMSSTATUS to determine the exception that occurred The inner error handler handles two special errors BAS K_RECNOTFOU and BAS K_ RECBUCLOC separately If the error signaled does not correspond to one of these the inner error handler passes control to the outer handler with the EXIT HANDLER statement The outer handler sets the program status to VMSSTATUS When the program exits the operating system displays any status that is of warning severity or greater PROGRAM Teste
43. The display of source lines is independent of program execution You can use the TYPE command to display source code from a module other than the one currently executing In that case you need to use a directory specification to specify the module For example the following command displays lines 16 to 21 of module TEST DBG gt TYPE TEST 16 21 3 2 Using the OpenVMS Debugger with BASIC 3 3 2 Screen Mode To invoke screen mode press PF3 In screen mode by default the debugger splits the screen into three displays called SRC OUT and PROMPT SRC module SAMPLESMAIN scroll source 1 10 SAMPLE 2 3 EXTERNAL SUB TRIPLE amp 4 PRINT SUB 53 6 WHEN ERROR USE HANDLER 1 gt 7 CALL TRIPLE 8 CALL PRINT SUB 9 OUT output stepped to SAMPLESMAIN LINE 7 PROMPT error program prompt DBG gt STEP DBG gt The SRC display at the top of the screen shows the source code of the module compilation unit that is currently executing An arrow in the left column points to the next line to be executed which corresponds to the current location of the program counter PC The line numbers which are assigned by the compiler match those in a listing file Note BASIC line numbers are treated as text by the debugger In this chapter line numbers refer to the sequential line numbers generated by the compiler When a p
44. The specified text path is invalid User Action Specify a valid text path Valid text path values are as follows e RIGHT the default e LEFT e UP e DOWN ILLTEXPRE Illegal text precision ERR 264 Explanation The specified precision string is invalid User Action Valid precision values are STROKE for software fonts STRING and CHAR for hardware fonts Specify a valid string for the precision value ILLTEXRAT Illegal text width to height ratio ERR 276 Explanation The specified width to height ratio is less than or equal to zero User Action Specify a width to height ratio greater than zero ILLTFFOPE Illegal terminal format file operation ERR 191 Explanation The program specifies a GETRFA function on a terminal format file User Action Change the file organization when opening the file to be sequential variable ILLTRANUM Illegal transformation number ERR 257 Explanation The specified tranformation number is less than 1 or greater than 255 User Action Specify a transformation number from 1 to 255 ILLUSADEYV Illegal usage for device ERR 133 Explanation The requested operation cannot be performed because e The device specification contains illegal syntax e The specified device does not exist on your system B 16 Run Time Messages e The specified device is inappropriate for the requested operation for example an indexed file access on magnetic tape User Action
45. User Action Specify a numeric variable You can use only numeric variables as loop control variables Compile Time Error Messages A 53 LOOINIMUS loop initial value must be a numeric expression Explanation ERROR A FOR statement attempts to assign a string expression as the loop control variable s initial value User Action Remove the string expression You can assign only numeric values as the loop s initial value LOOLIMMUS loop limit must be numeric Explanation ERROR A FOR statement attempts to assign a string expression as the loop control variable s limiting value User Action Remove the string expression You can assign only numeric values as the loop control variable s limiting value LOOWILNEY loop will never execute Explanation WARNING The program contains a FOR NEXT loop that is not executable for example FOR I 1 TO 0 Compilation continues but the loop is ignored User Action Change the loop parameters or insert an appropriate STEP clause LOWLSSUP lower bound must be less than upper bound Explanation ERROR The lower bound specified in the array is greater than the upper bound User Action Correct the bounds LOWNOTVIR lower bound not permitted with virtual arrays Explanation ERROR Lower bounds of virtual arrays must be zero User Action Correct the lower bounds to be zero LOWNOTZERO lower bound must be zero Explanation ERROR The lower bound of the array must be
46. amp STRING Translation buffer Buffer length Setting TRNSLNM to not distinguish between uppercase and lowercase letters in the logical name to be translated Attributes LNM M CASE BLIND continued on next page 19 20 Using BASIC in the Common Language Environment Example 19 3 Cont Calling System Services Assign values to each record item TRNLNM_ITEMS item 0 Buf_len Buffer length TRNLNM_ITEMS item 0 Code E LNM STRING TRNLNM_ITEMS item 0 Buffer_address LOC Translation_buffer TRNLNM_ITEMS item 0 Length address LOC Equiv_len TRNLNM_ITEMS item 1 Terminator 0 Invoke the function TRANS STATUS SYS TRNLNM attributes LNMSDCL_ LOGICAL logical_name amp trnlnm_items Check the condition value IF trans_status AND SS NORMAL THEN Translate LEFT Translation buffer Equiv_len ELSE Translate END IF END FUNCTION Example 19 4 is a program that demonstrates the use of the system service QIOW Unlike SYS QIO SYS QIOW performs synchronously SYS QIOW returns a condition value to the caller after I O operation is complete Example 19 4 Program Displaying the QIOW System Service Routine 10 Declare SYSSQIOW as an EXTERNAL FUNCTION EXTERNAL LONG FUNCTION SYSS QIOW WORD BY VALUE LONG BY VALUE WORD DIM amp BY REF STRING BY REF LONG BY VALUE amp LONG BY VALUE Declare SYSSASSIGN as an EXTERNAL FUNCTION EXTERNAL LONG FUNCTION SYSSASSIGN STRING WORD EXTER
47. are overwritten Also you must not set RMS Locate mode when using a USEROPEN routine on sequential files 13 8 12 WINDOWSIZE Clause The WINDOWSIZE clause specifies the number of block retrieval pointers in memory for the file WINDOWSIZE is not a file attribute and therefore can be changed any time you open a file Retrieval pointers are associated with the file header and point to contiguous blocks on disk By keeping retrieval pointers in memory you can reduce the I O associated with locating a record because the operating system does not have to access the file header for pointers as frequently The number of retrieval pointers in memory at any one time is determined by the system default or by the value you supply in the WINDOWSIZE clause The usual default number of retrieval pointers is 7 A value of zero specifies the default number of retrieval pointers A value of 1 specifies mapping the entire file if possible Values from 128 to 2 are reserved File Input and Output 13 43 14 Formatting Output with the PRINT USING Statement The PRINT USING statement controls the appearance and location of data on a line of output With it you can create formatted lists tables reports and forms This chapter describes how to format data with the PRINT USING statement 14 1 Overview of the PRINT USING Statement The ability to format data with the PRINT USING statement is useful because the way in which HP BASIC
48. assuming lt keyword gt to match lt keyword gt Explanation ERROR The program contains a syntax error HP BASIC assumes a keyword is misspelled and continues compilation under that assumption so that other errors can be detected The actual program line remains unchanged and no object file is produced User Action Examine the line carefully to discover the error Change the program line to correct the syntax error INSSPADYN insufficient space for MAP DYNAMIC variable in MAP lt name gt Explanation ERROR A variable named in a MAP DYNAMIC statement is larger than the MAP for example a GFLOAT variable in a MAP that is only four bytes long User Action Increase the size of the MAP so that it is large enough to hold the largest member INTCODERR an internal coding error has been detected Submit an SPR Explanation ERROR An error has been detected in the HP BASIC compiler User Action Please submit a software problem report SPR with the source code of a small program that produces this error INTCONEXC integer constant exceeds machine integer size Explanation ERROR The value specified in a DECLARE CONSTANT statement exceeds the largest allowable value for an integer User Action Supply a value in the valid range INTCONREQ integer constant required Explanation ERROR The program contains a noninteger named constant in a context that requires an integer For example DIM A 123 D User Action
49. it can access data by calculating the distance from the beginning of the file to the desired data If there is not enough contiguous disk space BASIC allocates as much contiguous space as possible For truly contiguous records you must use the USEROPEN clause and set the CTG bit in the FAB FOP field see the OpenVMS Record Management Services Reference Manual Opening a file with both the FILESIZE and CONTIGUOUS clauses pre extends the file contiguously or in as few disk extents as possible DEFAULTNAME Clause The DEFAULTNAME clause in the OPEN statement lets you specify a default file specification for the file to be opened It is valid with all file organizations BASIC uses the DEFAULTNAME clause for any part of the file specification that is not explicitly supplied LINPUT Next data file Fils OPEN Fil FOR INPUT AS FILE 5 amp ORGANIZATION SEQUENTIAL amp DEFAULTNAME USERSDEVICE DAT The DEFAULTNAME clause supplies default values for the device directory and file type portions of the file specification Typing ABC in response to the Next data file prompt causes BASIC to try to open USER DEVICE ABC DAT BASIC uses the DEFAULTNAME values only if you do not supply those parts of the file specification appearing in the DEFAULTNAME clause For example if you type SYS DEVICE ABC in response to the prompt BASIC tries to open SYS DEVICE ABC DAT In this case SYS DEVICE overrides the device default in the DEFAULTNAME cla
50. row and column zero The MAT PRINT statement takes values from an array by row starting with element 1 1 and writes each element to a sequential record in the terminal format file Subscripts are optional in MAT PRINT statements If you do not specify subscripts MAT PRINT displays the entire array excluding row and column zero If you specify subscripts MAT PRINT displays the specified subset of the array In the case of the MAT PRINT statement the subscripts determine how many array elements are written to the file The MAT PRINT statement does not redimension an existing array If the last character in the MAT PRINT array list is a semicolon BASIC begins each array row on a separate line Data values on each line are packed together with no intermediate spaces However if the last character in the MAT PRINT array list is a comma BASIC begins each array row on a separate line and each data value in a separate print zone If there is neither a comma nor a semicolon after the array name BASIC prints each array element on a separate line In the following example the first MAT PRINT statement does not end in a comma or semicolon so each element is printed on a separate line The second MAT PRINT statement prints the elements twice the first time starting each element in a new print zone and the second time leaving a space before and after each value The MAT PRINT statement sends the last two lines of output to a t
51. unterminated string literal Explanation ERROR The program contains an improperly terminated string literal for example ABC ABC and ABC are all improperly terminated User Action Use the same type of quotation mark either single or double for both beginning and ending string delimiters USEONLALO USE only allowed inside WHEN blocks Explanation ERROR A USE statement is not within a WHEN block User Action Remove the USE statement A 88 Compile Time Error Messages USERABORT user ABORT directive lt text gt Explanation FATAL The compilation was terminated as the result of a ABORT directive The compiler prints the text following the 7ABORT User Action None USERPRINT lt text gt Explanation SUCCESS The compilation found a PRINT directive and printed the specified message to the terminal and listing file User Action None USEVARNOT user variable lt name gt not allowed in declaration Explanation ERROR The parameter list in an external subprogram declaration contains a user variable name User Action Remove the variable from the parameter list When declaring a routine the parameter list can contain only data type and parameter passing mechanism specifications VALTOOLAR value too large for constant Explanation WARNING The value of an EXTERNAL CONSTANT is larger than the specified data type allows User Action Make sure the data type specified in the EXTERNAL CONSTANT s
52. 10 STRING Last name 20 STRING Soc_sec_number 11 END RECORD Employee Declarations DECLARE Employee Emp rec DECLARE STRING Social security Program logic starts here INPUT Employee number Emp rec Emp number INPUT First name Emp rec First name INPUT Last name Emp rec Last name INPUT Social security Social security IF Social security lt gt THEN Emp rec Soc sec number Social security END IF 7 8 2 Creating and Using Data Structures PRINT PRINT Employee number is Emp rec Emp number PRINT First name is Emp rec First name PRINT Last name is Emp rec Last name PRINT Social security is Emp rec Soc_sec_number END When you access an array of RECORD instances the array subscript should immediately follow the name of the RECORD variable The following example shows an array of RECORD instances Record Template RECORD Employee LONG Emp number STRING First name 10 STRING Last name 20 STRING Soc_sec_number 11 END RECORD Declarations DECLARE Employee Emp array 10 DECLARE INTEGER Index DECLARE STRING Social security Program logic starts here FOR Index 0 TO 10 PRINT INPUT Employee number Emp array Index Emp_number INPUT First name Emp _array Index First_name INPUT Last name Emp_array Index Last_name INPUT Social security Social security IF Social security lt gt THEN a Emp _array Index
53. 13 3 virtual 13 4 Files appending 2 2 closing 13 31 deleting with KILL statement 13 31 file related functions 13 31 to 13 34 including 16 7 opening with OPEN statement 13 11 renaming with NAME AS statement 13 30 restoring 13 29 to 13 30 transferring data to 13 29 truncating with SCRATCH statement 13 30 FILL formats 7 10 FILL items 7 9 FIND statement 13 14 to 13 16 random access 13 15 sequential 13 14 Fixed length strings 11 1 changing 11 3 using 11 3 FIXED record formats specifying 18 2 FIX function 10 2 FLAG qualifier 2 9 Floating point variables 4 10 Floating point numbers displaying with PRINT USING statement 14 1 FOR NEXT loops 9 3 to 9 6 FORMATS function 10 8 Format characters with PRINT USING statement 14 6 Format fields with PRINT USING statement 14 2 Format strings with PRINT USING statement 14 2 Formatting characters with PRINT statement 5 9 FOR modifier 9 1 FORTRAN arrays 19 8 FREE statement 13 24 to 13 25 FSP function 13 32 FULL 2 24 FUNCTION 12 8 to 12 4 Function call 19 6 Functions 10 1 to 10 24 built in 10 1 date and time 10 13 to 10 15 string arithmetic 10 10 to 10 13 terminal control 10 15 creating with DEF 10 18 to 10 24 data conversion 10 6 declaring 10 21 external 12 3 file related 13 31 to 13 34 naming 10 18 10 19 10 21 numeric string 10 7 parameter data types 10 2 recursion in 10 23 resultant data type 10 2 string ar
54. 14 describes how to format output with the PRINT USING statement Chapter 15 explains error handling techniques Chapter 16 shows how to use compiler directives Chapter 17 describes how BASIC represents data Part Ill Using HP BASIC Features on OpenVMS Systems Chapter 18 describes additional I O considerations on OpenVMS systems Chapter 19 describes OpenVMS System Services and Run Time Library routines Chapter 20 describes the use of user supplied libraries and shareable images Chapter 21 describes how to use CDD Repository capabilities Chapter 22 describes using standard Motif Bindings with BASIC Appendixes Appendix A lists compile time error messages Appendix B lists run time error messages Appendix C provides an overview of the optional productivity tools Related Documents For more information about language elements syntax and reference information see the HP BASIC for OpenVMS Reference Manual Reader s Comments HP welcomes your comments on this manual Please send comments to either of the following addresses Internet openvmsdoc hp com Postal Mail Hewlett Packard Company OSSG Documentation Group ZKO3 4 U08 110 Spit Brook Rd Nashua NH 03062 2698 Conventions The following product names may appear in this manual e HP OpenVMS Industry Standard 64 for Integrity Servers e OpenVMS I64 e 164 All three names the longer form and the two abbreviated forms refer to the version of the OpenVMS
55. 16 NO JCROSS_REFERENCE 2 23 NOJDEBUG 2 24 NOJEXECUTABLE 2 24 NOJMAP 2 24 NO JSHAREABLE 2 24 NO JTRACEBACK 2 24 Null character 11 3 string 11 3 NUMS function 10 8 NUM1 function 10 8 Numbers printing with PRINT USING statement 14 3 Numeric data interpreting with multiple maps 7 9 NUM function 6 18 O Object module libraries 20 3 creating 20 3 module names in 4 4 Object module library using 2 26 Object modules producing with OBJECT 2 11 OBJECT qualifier 2 11 OLD_VERSION CDD_ARRAYS qualifier 2 11 ON ERROR GO BACK statement 15 22 ON ERROR GOTO statement 15 21 passing to default error handler 15 21 ON ERROR statement 15 20 15 21 to 15 23 OPEN statement 5 14 13 11 BUCKETSIZE 13 34 clauses for optimizing I O 13 34 to 13 43 control structures set by USEROPEN keyword 13 40 EXTENDSIZE clause 13 38 FOR INPUT 13 11 FOR OUTPUT 13 11 keyword 13 40 opening indexed files 13 13 ORGANIZATION UNDEFINED 13 32 RECORDSIZE 13 12 RECORDTYPE ANY 13 32 specifying file characteristics with 13 12 UNLOCK EXPLICIT 13 24 with BUFFER clause 13 36 with CONNECT clause 13 36 with CONTIGUOUS clause 13 37 with DEFAULTNAME clause 13 37 OPEN statement cont d with FILESIZE clause 13 38 with MAP clause 13 12 with NOSPAN clause 13 39 with RECORDTYPE clause 13 39 with TEMPORARY clause 13 40 with USEROPEN keyword 13 40 with WINDOWSIZE attribute 13 43 OpenVMS
56. 39 37 MAT cm array 2 54 inch array MAT PRINT cm array 5 END Output 2 54 30 48 91 44 254 99 9998 6 7 2 Matrix Functions BASIC provides the following matrix functions TRN INV DET With these functions you can transpose and invert matrices and find the determinant of an inverted matrix 6 7 2 1 TRN Function The TRN function transposes a matrix When you transpose a matrix BASIC interchanges the array s dimensions For example a matrix with n rows and m columns is transposed to a matrix with m rows and n columns The elements in the first row of the input matrix become the elements in the first column of the output matrix You cannot transpose a matrix to itself MAT A TRN A is invalid The following example creates a 3 by 5 matrix transposes it and prints the results DIM B 3 5 MAT READ B MAT A TRN B DATA 1 2 3 4 5 DATA 6 7 8 9 10 DATA 11 12 13 14 15 MAT PRINT B MAT PRINT A END Arrays 6 21 Output 12345 6789 10 11 12 13 14 15 1 6 11 2 7 12 3 8 13 4 9 14 5 10 15 6 7 2 2 INV Function The INV function inverts a matrix BASIC can invert a matrix only if its subscripts are identical and it can be reduced to the identity matrix by elementary row operations The input matrix multiplied by the output matrix its inverse always gives the identity matrix as a result MAT INPUT first array 3 3 MAT PRINT first array PRINT MAT inv array INV first array MAT PRINT inv arra
57. 66 Compile Time Error Messages OPTBASMUS OPTION BASE must be before array declarations Explanation ERROR A program compiled with the ANSI_STANDARD qualifier contains an OPTION BASE statement that lexically follows an array declaration User Action Move the OPTION BASE statement so that it lexically precedes the array declaration OPTCLACON OPTION clause occurs more than once Explanation ERROR The OPTION statement contains a duplicate clause for example specifying the default integer size as both BYTE and LONG User Action Remove one of the clauses OPTNOTALL OPTIONAL not allowed on EXTERNAL PICTURE Explanation ERROR An attempt was made to specify the OPTIONAL keyword on an EXTERNAL PICTURE declaration This is not allowed because OPTIONAL parameters should be used for calling non BASIC procedures only User Action Remove the OPTIONAL keyword from the EXTERNAL PICTURE declaration OPTOUTSEQ OPTION statement out of sequence Explanation ERROR The OPTION statement is either 1 not the first statement in a main program or 2 not the first statement following the SUB or FUNCTION statement User Action Move the OPTION statement so that it is either the first statement in the main program or the first statement following the SUB or FUNCTION statement in the subprogram ORGUNDREQ ORGANIZATION UNDEFINED requires FOR INPUT clause Explanation ERROR The program opens a file with ORGANIZATION UNDEFINED b
58. A 31 FILNOTDEL error deleting lt file name gt Explanation ERROR An error was detected in attempting to delete a file User Action Supply a valid file specification or take corrective action based on the associated message FILTOOBIG FILL number lt n gt in overlay lt m gt of MAP lt name gt too big Explanation ERROR A FILL string length or repeat count caused the compiler to try to allocate more than 2 31 longwords of storage User Action Check the specified MAP statement and change the FILL string length or repeat count FLDNOALGN FIELD lt field name gt within RECORD lt record_name gt is not naturally aligned Explanation WARNING Identifies a field within a record that was found not to be naturally aligned This error is reported only when the WARNING ALIGNMENT qualifier is in effect User Action Modify the record so that all fields are naturally aligned FLOCVTILL floating CVT valid only for SINGLE and DOUBLE Explanation ERROR A CVTF or CVT F function names a GFLOAT HFLOAT SFLOAT TFLOAT or XFLOAT value as an argument or the default real size is one of these User Action Use a SINGLE argument rather than SFLOAT Use a DOUBLE argument rather than GFLOAT TFLOAT HFLOAT or XFLOAT FLOPOIERR floating point error or overflow Explanation WARNING The program contains a numeric expression whose value is outside the valid range for the default floating point data type User Action Modify
59. ALLOW NONE clause To allow less restrictive access to the open file specify ALLOW READ or ALLOW MODIFY When a file is open for read access only and you have not restricted access to other programs with ALLOW NONE BASIC allows other programs to read any record in the file including records that your program is concurrently accessing However when you retrieve a record with the GET statement from a file you have opened with the intent to modify BASIC normally restricts other programs from accessing that record This restriction is called locking To allow other programs to access a record you have locked you must release the lock on the record in one of the following ways e Retrieve another record on the same channel Unless you have opened the file with the UNLOCK EXPLICIT clause see the following discussion this action will unlock the previous record e Explicitly unlock the record with the UNLOCK or FREE statement The UNLOCK statement releases the current record The FREE statement releases all records locked on a given channel e Perform an UPDATE operation on the record An UPDATE statement causes the current record to be unlocked e Close the file In addition to the capability of restricting access through the OPEN statement ALLOW clause BASIC allows programs to explicitly control record locking on each record that is retrieved To use explicit record locking on a file the OPEN statement must include an UNLOCK EXPLICIT
60. ANALYSIS_DATA qualifier generates a file containing data analysis information This file has the file type ANA The Source Code Analyzer SCA library uses these files to display cross reference information and to analyze source code Developing HP BASIC Programs 2 3 Remarks e SCA must be installed GENERIC HOST EV4 Alpha only EV5 Alpha only EV56 Alpha only PCA56 Alpha only EV6 Alpha only EV67 Alpha only ITANIUM2 164 only MERCED I64 only ARCHITECTURE ARCHITECTURE GENERIC default The ARCHITECTURE qualifier specifies which version of the Itanium or Alpha architecture to generate instructions for All Itanium and Alpha processors implement a core set of instructions and in some cases the following extensions BWX byte and word manipulation instructions and MAX multimedia instructions OpenVMS Version 7 1 and subsequent releases include an instruction emulator This capability allows any Itanium or Alpha chip to execute and produce correct results from Itanium or Alpha instructions respectively even if some of the instructions are not implemented on the chip Applications using emulated instructions will run correctly but might incur significant emulation overhead at run time Remarks e ARCHITECTURE GENERIC default generates instructions that are appropriate for all Itanium or Alpha processors e ARCHITECTURE HOST generates instructions for the Itanium or Alpha processor
61. B is subtracted from A PROD PROD A B P A is multiplied by B The product is expressed with precision P QUO QUO A B P A is divided by B The quotient is expressed with precision P PLACE PLACE A P A is expressed with precision P String arithmetic computations permit 56 significant digits The functions QUO PLACE and PROD however permit up to 60 significant digits Table 10 2 shows how HP BASIC determines the precision permitted by each function and if that precision is implicit or explicit Table 10 2 Precision of String Arithmetic Functions Function How Determined How Stated SUM Precision of argument Implicitly DIF Precision of argument Implicitly PROD Value of argument Explicitly QUO Value of argument Explicitly PLACE Value of argument Explicitly 10 10 Functions 10 1 4 1 10 1 4 2 SUMS and DIF Functions The SUM and DIF functions take the precision of the more precise argument in the function unless padded zeros generate that precision SUM and DIF omit trailing zeros to the right of the decimal point The size and precision of results returned by the SUM and DIF functions depend on the size and precision of the arguments involved e The sum or difference of two integers takes the precision of the larger integer e The sum or difference of two decimal fractions takes the precision of the more precise fraction e The sum or difference of two real numbers t
62. BASIC rounds it to 6 digits When you print a floating point number with more than 6 digits and with magnitude smaller than 0 1 BASIC rounds it to 6 digits and prints it in E format The PRINT statement displays only up to 6 digits of precision for floating point numbers This corresponds to the precision of the SINGLE or SFLOAT data types To display the extra digits in DOUBLE GFLOAT TFLOAT or XFLOAT numbers you must use the PRINT USING statement See Chapter 14 for more information about the PRINT USING statement 5 12 Simple Input and Output The following example shows how BASIC prints various numbers with single precision FOR I 1 TO 20 PRINT 2 I I 2 I NEXT I END Output a5 1 2 225 2 4 125 3 8 0625 4 16 03125 5 32 015625 6 64 78125E 02 7 128 390625E 02 8 256 195313E 02 9 512 976563E 03 10 1024 488281E 03 11 2048 244141E 03 12 4096 12207E 03 13 8192 610352E 04 14 16384 305176E 04 15 32768 152588E 04 16 65536 767939E 05 17 131072 38147E 05 18 262144 190735E 05 19 524288 953674E 06 20 104858E 07 5 3 Terminal Format Files Terminal format files let you perform simple I O to disk files The records in a terminal format file must be accessed sequentially That is you must access the records in the file one by one from the first to the last You can add new records only at the end of the file Just as the INPUT LINPUT and INPUT LINE statements receive information from a terminal the INPU
63. CASE statement the CONTINUE statement causes HP BASIC to resume execution at the statement following the end of the loop structure the NEXT END CASE or END SELECT statements Note When you use the RETRY or the CONTINUE statement without a target the compiler builds read only tables in the generated object file with information about statements in the associated protected regions Therefore when space is extremely critical do not protect large regions with handlers containing RETRY or CONTINUE without a specified target Handling Run Time Errors 15 9 15 2 3 3 EXIT HANDLER Statement Unlike RETRY and CONTINUE the EXIT HANDLER statement does not clear the error rather it allows you to exit from the handler with the error pending This allows you to pass an error to the handler associated with the next outer protected region or back to HP BASIC default error handling or to the calling procedure When an error occurs within a nested protected region control passes to the handler associated with the innermost protected region in which the error occurred If the innermost handler does not handle the error the error is passed to the next outer handler with the EXIT HANDLER statement All handlers for any outer WHEN ERROR blocks are processed before reverting to default error handling or resignaling the calling procedure The following example shows two nested protected regions Neither handler traps division by zero If d
64. DATES 0 PRINT DATES 126 PRINT DATE 6168 END Output 15 Jun 85 06 May 70 16 Jun 76 If you supply an invalid date for example day 370 of the year 1973 the results are undefined See Section 10 1 5 2 for the recommended replacement for DATE which has a two digit year field in the result string DATE4 Function The DATE4 function is strongly recommended as replacement for the DATE function to avoid problems in the year 2000 and beyond It functions the same as the DATE function except that the year portion of the result string contains two more digits indicating the century For example PRINT 32150 DATES 32150 DATE4S 32150 Produces the following output 32150 30 May 02 30 May 2002 See the description of the DATE function for more information TIMES Function The TIME function returns a string displaying the time of day in the form hh mm AM or hh mm PM TIME returns the time of day at a specified number of minutes before midnight If you specify zero in the numeric expression TIME returns the current time of day For example 10 14 Functions PRINT TIMES 0 PRINT TIMES 1 PRINT TIME 1440 PRINT TIME 721 END Output 03 53 PM 11 59 PM 12 00 AM 11 59 AM 10 1 5 4 TIME Function The TIME function requests time and usage information from the operating system and returns it to your program The information returned by the TIME function depends on the value of the argument passed to it T
65. END GIF 16 9 INCLUDE 16 7 16 8 21 7 INCLUDE FROM CDD 21 2 21 4 21 6 LET 16 8 16 9 LIST 16 2 16 5 NOCROSS 16 2 16 6 NOLIST 16 2 16 5 PAGE 16 2 16 4 REPORT DEPENDENCY 21 2 21 10 SBTITL 16 2 16 3 TITLE 16 2 VARIANT 16 8 16 10 Directory CDO format 21 4 directory specification in debugging 3 2 3 5 3 7 3 8 Disks accessing 18 10 creating 18 11 opening 18 11 opening an existing disk file 18 11 Disk unit allocating 18 11 Display source code 3 2 Division by zero 15 2 Dynamic mapping 7 13 13 7 to 13 9 Dynamic storage 4 8 allocating 7 4 Dynamic string descriptors 17 10 Dynamic strings concatenating 11 2 modifying 11 3 using 11 2 Index 5 E ECHO function 10 16 EDIT function string function 11 16 Editor LSE C 1 to C 4 Elliptical references 8 9 ELSE clause 9 10 END FUNCTION statement 12 3 specifying expression with 12 4 END HANDLER statement 15 7 END IF statement 9 10 END SUB statement 12 3 END WHEN statement 15 7 Entities CDO format dictionary 21 4 ERL function 15 138 15 14 ERN function 15 14 ERR function 15 12 Error conditions with PRINT USING statement 14 16 Error handlers debugging 15 20 user written 15 2 to 15 20 Error handling 15 1 to 15 23 default 15 1 to 15 2 Error messages compile time A 1 Errors forcing 15 20 handling in DEF s 15 19 handling in functions 15 19 handling in subprograms 15 18 to 15 20 handling O
66. ERROR IN OPEN file txt FOR OUTPUT AS FILE 1 PRINT 1 TIME 0 USE Error 12 is fatal system I O failure IF ERR 12 THEN PRINT An unexpected RMS error has occurred PRINT Status RMSSTATUS 1 PRINT Value RMSSTATUS 1 VALUE EXIT HANDLER END IF END WHEN CLOSE 1 GOTO done done END If you want to find an RMS status without knowing which particular channel to check you can use VMSSTATUS to get the STATUS value STS if an error has occurred 15 16 Handling Run Time Errors 15 2 6 Ctrl C Trapping Error handling procedures are commonly used to trap user Ctrl C responses With Ctrl C trapping enabled control is transferred to an error handler if a user presses Ctrl C during program execution You enable Ctrl C trapping in your program by invoking the built in CTRLC function For example Y CTRLC After you invoke the CTRLC function a Ctrl C entered at the terminal transfers control to the error handler Once the Ctrl C is trapped you can include routines to interact with the program as shown in the following example WHEN ERROR IN Y CTRLC OPEN FIL DAT FOR INPUT AS FILE 1 INPUT HOW MANY RECORDS Rec read FOR I 1 TO Rec read D GET 1 PRINT Name Address Emp code PRINT NEXT I USE Trap C IF ERR 283 THEN PRINT CURRENT RECORD IS I ELSE EXIT HANDLER END IF CONTINUE Clean up END WHEN Clean up CLOSE 1 PRINT END OF PROCESSING END Output
67. EXPLICIT clause in the OPEN statement ILLRESSUB Illegal RESUME to subroutine ERR 247 Explanation While in an error handler activated by an ON ERROR GO BACK the error handler attempts to RESUME without a line number This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action None you cannot specify the RESUME statement without a line number in any program module except in the program module containing the error handler ILLSTYIND Illegal area style index ERR 279 Explanation The specified area style index is less than or equal to zero User Action Specify a valid area style index greater than zero ILLSWIUSA Illegal switch usage ERR 67 Explanation The program attempts an illegal SYS call User Action See the appropriate RSTS E SYS call documentation ILLSYSUSA Illegal SYS usage ERR 18 Explanation The program attempted an illegal SYS call User Action See the appropriate RSTS E SYS call documentation ILLTEXHEI Illegal text height ERR 278 Explanation The text height is less than or equal to zero User Action Specify a text height greater than zero ILLTEXJUS Illegal text justification ERR 263 Explanation The specified text justification factor is invalid User Action See Programming with VAX BASIC Graphics for valid justification values Specify valid values Run Time Messages B 15 ILLTEXPAT Illegal text path ERR 265 Explanation
68. If you are using a map only the first n bytes n is the value returned in RECOUNT are valid 18 8 Advanced File Input and Output 18 2 2 4 18 2 2 5 Writing Records to a File The PUT statement writes records to the file in sequential order For example OPEN MTO FOR OUTPUT AS FILE 9 amp SEQUENTIAL VARIABLE INPUT NAME NA MES MOVE TO 9 NA MES PUT 9 The last line writes the contents of the record buffer to the device Successive PUT operations write successive records The default record length and therefore the size of the buffer is 132 bytes The RECORDSIZE attribute causes HP BASIC to read or write records of a specified length For example the following statement opens tape unit MTO and specifies records of 900 characters You must specify an even integer larger than or equal to 18 If you specify a buffer length less than 18 HP BASIC signals an error If you try to write a record longer than the buffer HP BASIC signals the error Size of record invalid ERR 156 OPEN MTO FOR INPUT AS FILE 1 RECORDSIZE 900 To write records shorter than the buffer include the COUNT clause with the PUT statement The following statement writes a 56 character record to the file open on channel 6 If you do not specify COUNT HP BASIC writes a full buffer You can specify a minimum count of 18 and a maximum count equal to the buffer size When writing records to a foreign magnetic tape neither HP BASIC nor R
69. In the following example when BASIC encounters the LIST directive it resumes adding new information to the listing file STITLE Payroll Program SSBTTL Constant Declarations SNOLIST LIST PAGE SSBTTL Subroutines PAGE SBTTL Error Handler Compiler Directives 16 5 If you have not requested the creation of a compilation listing the LIST and NOLIST directives have no effect If a program line contains a syntax error BASIC overrides the NOLIST directive for that line and produces the normal error diagnostics in the listing file 16 2 5 CROSS and NOCROSS Directives The CROSS and NOCROSS directives are complementary The CROSS directive causes BASIC to resume adding cross reference information while the NOCROSS directive causes BASIC to stop adding cross reference information to the listing file Therefore you can specify that only certain parts of the source program are to be cross referenced In the following example as soon as BASIC encounters the CROSS directive it resumes adding new cross reference information to the listing file STITLE Payroll Program SSBTTL Constant Declarations SNOCROSS CROSS PAGE SSBTTL Subroutines PAGE SBTTL Error Handler If you have not requested the creation of a cross reference listing the CROSS and NOCROSS directives have no effect 16 6 Compiler Directives 16 3 Accessing External Source Files The INCLUDE directive lets you access BASIC
70. O buffer of 1080 bytes Each physical read or write operation moves 1080 bytes of data between the tape and this buffer Every twelfth GET or PUT operation causes a physical read or write The next eleven GET or PUT operations only move data into or out of the I O buffer Specifying a block size larger than the default can reduce overhead by eliminating some physical reading and writing to the tape In addition specifying a large block size conserves space on the tape by reducing the number of interrecord gaps IRGs In the example a block size of 12 saves time by accessing the tape only after every twelfth record operation OPEN MTO SMITH TEST SEQ FOR OUTPUT AS FILE 12 amp ORGANIZATION SEQUENTIAL FIXED RECORDSIZE 90 amp BLOCKSIZE 12 Advanced File Input and Output 18 5 18 1 8 18 1 9 Through RMS HP BASIC controls the blocking and deblocking of records RMS checks each PUT operation to see if the specified record fits in the tape block If it does not RMS fills the rest of the block with circumflexes blanks and starts the record in a new block Records cannot span blocks in magnetic tape files When you read blocks of records your program can issue successive GET statements until it locates the fields of the record you want The following program finds and displays a record on the terminal You can invoke the RECOUNT function to determine how many bytes were read in the GET operation MAP XXX NA MES 5 address
71. O operations are complete QIOW returns to the caller 19 6 OpenVMS Calling Standard The primary purpose of the OpenVMS Calling Standard is to define the concepts for invoking routines and passing data between them For more information see the HP OpenVMS Calling Standard 19 22 Using BASIC in the Common Language Environment 19 7 Additional Information The information provided on system routines in this chapter is general to all system services and OpenVMS Run Time Library routines For specific information about these routines see the VMS Run Time Library Routines Volume and the HP OpenVMS System Services Reference Manual Using BASIC in the Common Language Environment 19 23 20 Libraries and Shareable Images Libraries and shareable images allow you to access program symbols and incorporate commonly used routines into your source code This chapter describes how to create and access libraries and shareable images in HP BASIC 20 1 Overview of Libraries Libraries are files that can contain object modules text modules and shareable images There are two types of libraries system supplied and user supplied System supplied libraries are provided by the OpenVMS system and user supplied libraries are libraries that you create Shareable images are similar to libraries they contain code that can be shared by other programs However shareable images contain executable code rather than object code If you have routines
72. PUT THEN PRINT IN FUNCTION CONTINUE ELSE PRINT IN MAIN CONTINUE Invoke def END IF END WHEN Main code DEF FNIN PUT P WHEN ERROR IN PRINT PS INPUT LINE INS FNIN PUTS INTEGER LINE_INS USE IF ERR 50 THEN RETRY ELSE EXIT HANDLER END IF END WHEN END DEF Handling Run Time Errors 15 19 Note If you invoke a GOSUB statement or a DEF function from within a protected region and the invoked procedure is outside of any protected region all pending errors are handled by the WHEN ERROR handler unless a previously executed ON ERROR statement specifies otherwise 15 2 8 Forcing Errors The CAUSE ERROR statement allows a program to artificially generate an error when the program would not otherwise do so You can force any HP BASIC run time error You must specify the number of the error the compiler should force the error numbers are listed in Appendix B The following statement forces an end of file error ERR 11 to occur CAUSE ERROR 11 You can use this feature to debug an error handler during program development as shown in the following example WHEN ERROR IN CAUSE ERROR 11 USE SELECT ERR CASE 11 PRINT Trapped an end of file on device CONTINUE CASE ELSE EXIT HANDLER END WHEN 15 3 Using the ON ERROR Statements HP BASIC supports ON ERROR statements as an alternative to WHEN blocks primarily for compatibility with existing programs WHEN ERROR blocks are similar to declarative statem
73. RECORD 8 1 Terminal format files 13 3 channel specification for 5 14 closing 5 14 input and output 5 13 to 5 15 opening 5 14 transferring data to 13 29 writing records to 5 14 Text libraries accessing 16 7 creating 16 7 system supplied 16 7 THEN clause 9 10 TIME function 10 14 TIME function 10 15 TITLE directive 16 2 Traceback SHOW CALLS debugger command 3 6 Tracepoint 3 9 TRM function string function 11 16 TRN function 6 21 TYPE debugger command 3 2 TYPE_DEFAULT qualifier 2 17 U UBOUND function 6 8 UNDEFINE 16 12 UNLESS modifier 9 1 UNLOCK EXPLICIT clause 13 24 UNLOCK statement 13 24 UNTIL NEXT loops 9 7 UNTIL modifier 9 1 UPDATE statement 13 21 to 13 23 current and next record pointers after 138 22 in an indexed file 13 23 in a relative file 13 23 in a sequential file 13 22 Upper bounds with COMMON statement 7 5 with MAP statement 7 6 with the RECORD statement 8 4 V VAL function 10 9 VAL function 10 9 Variable name DEPOSIT debugger command 3 12 EVALUATE debugger command 3 13 EXAMINE debugger command 3 11 VARIABLE record formats specifying 18 2 Index 15 Variables 4 10 arrays of 4 10 4 11 declaring 4 6 7 3 floating point 4 10 initialization of 4 12 integer 4 10 names 4 10 packed decimal 4 11 redefining 7 12 string 4 11 11 1 subscripted 4 10 4 11 VARIANT 8 5 to 8 8 VARIANT directive 16 8 16 10 VARIANT
74. RMS error when accessing the specified file User Action Take action based on the reported RMS error number INCSUBUSE inconsistent subscript use for lt array name gt Explanation ERROR The number of subscripts in an array reference does not match the number of subscripts specified when the array was created User Action Specify the same number of subscripts INIOUTRAN initial value must be within the specified range Explanation ERROR The specified initial value is not within the range specified in the RANGE clause User Action Change either the initial value or the range values so that the initial value falls within the range INPPROMUS input prompt must be a string constant Explanation ERROR An INPUT LINPUT or INPUT LINE statement list contains a numeric constant immediately following the statement User Action Remove the numeric constant You can specify only a string constant immediately after an INPUT LINPUT or INPUT LINE statement Compile Time Error Messages A 43 INSERTB assuming lt keyword gt before lt keyword gt Explanation ERROR The program contains a syntax error HP BASIC assumes a keyword is missing and continues compilation under that assumption so that other errors can be detected The actual program line remains unchanged and no object file is produced User Action Examine the line carefully to discover the error Change the program line to correct the syntax error INSERTM
75. Repository field name SINGLE SINGLE_R_VALUE SINGLE SINGLE_I_VALUE END GROUP GROUP CDD Repository field name DOUBLE DOUBLE_R_VALUE DOUBLE DOUBLE_I_VALUE END GROUP GROUP CDD Repository field name GFLOAT GFLOAT_R_VALUE GFLOAT GFLOAT_I_VALUE END GROUP GROUP CDD Repository field name HFLOAT HFLOAT_R_VALUE HFLOAT HFLOAT_I_VALUE END GROUP GROUP CDD Repository field name STRING STRING_VALUE Es Es Es Es Es length END GROUP continued on next page Using CDD Repository with BASIC 21 19 Table 21 2 Cont Unsupported CDD Repository Data Types Data Type HP BASIC Translation UNSIGNED NUMERIC GROUP CDD Repository field name STRING STRING_VALUE length END GROUP LEFT SEPARATE NUMERIC GROUP CDD Repository field name STRING STRING_VALUE length 1 END GROUP LEFT OVERPUNCHED GROUP CDD Repository field name NUMERIC STRING STRING_VALUE length END GROUP RIGHT SEPARATE NUMERIC GROUP CDD Repository field name STRING STRING_VALUE length 1 END GROUP RIGHT OVERPUNCHED GROUP CDD Repository field name NUMERIC STRING STRING_VALUE length END GROUP VARYING STRING GROUP CDD Repository field name WORD WORD_VALUE STRING STRING_VALUE length END GROUP BIT GROUP CDD Repository field name STRING STRING_VALUE length 8 END GROUP DATE GROUP CDD Repository field name STRING STRING_VALUE 8 END GROUP POINTER GROUP CDD Repository field name LONG LONG_VALUE END GROUP
76. Section 2 1 3 Command Qualifier NOJANALYSIS_DATA file specification ARCHITECTURE arch type NOJAUDIT text entry NO JCHECK check clause NO JCROSS_REF NO KEYWORDS NO DEBUG debug clause DECIMAL_SIZE d s NO DEPENDENCY_DATA NO DIAGNOSTICS file specification NO FLAG flag clause INTEGER_SIZE data type NO JLINES NO LISTING file specification NOJMACHINE_CODE NOJOBJECT file specification NOJOLD_VERSION CDD_ARRAYS NOJOPTIMIZE LEVEL n REAL_SIZE data type NOJROUND_DECIMAL SCALE n NO SEPARATE_COMPILATION NO JSHOW show item NOJSYNCHRONOUS_EXCEPTIONS TYPE_DEFAULT default clause VARIANT int const NO JWARNINGS warn clause Default NOANALYSIS_DATA ARCHITECTURE GENERIC NOAUDIT CHECK BOUNDS OVERFLOW NOCROSS_REF DEBUG TRACEBACK SYMBOLS DECIMAL_SIZE 15 2 NODEPENDENCY_DATA NODIAGNOSTICS FLAG NODECLINING JINTEGER_SIZE LONG NOLINES NOLISTING from terminal LISTING batch NOMACHINE_CODE OBJECT NOOLD_VERSION OPTIMIZE LEVEL 4 REAL_SIZE SFLOAT 164 or SINGLE Alpha NOROUND_DECIMAL SCALE 0 NOSEPARATE_COMPILATION SHOW NOSYNCHRONOUS_EXCEPTIONS TYPE_DEFAULT REAL VARIANT 0 WARNINGS INFORMATIONALS WARNINGS NOALIGNMENT NOJANALYSIS_ DATA file specification NOANALYSIS_DATA default The
77. Single test and a separate single instance of type Test The minimal reference to the string Group_1_string in RECORD instance Array_of_test is as follows Array _of_test i Group_1 string In this case i is the subscript for array Array_of_test Because the RECORD instance is itself an array the reference must include a specific array element 8 10 Creating and Using Data Structures Because Single_test is not an array the minimal reference to string Group_1_ string in RECORD instance Single_test is as follows Single test Group 1 string The minimal reference for the REAL variable My_number in GROUP Group_1 in RECORD instance Array_of_test is as follows Array of _test i Group_1 My number Here i is the subscript for array Array_of_test The minimal reference to the REAL variable My_number in RECORD instance Single_test is as follows Single test Group_1 My_ number Because there is a variable named My_number in groups Group_1 and Group_ 2 you must specify either Group_1 My_number or Group_2 i My_number In this case extra component names are required to resolve an otherwise ambiguous reference The minimal reference to the DECIMAL variable Group_2_decimal in RECORD instances Array_of_test and Single_test are the fully qualified references In the following examples i is the subscript for array Array_of_test and j is an index into the group array Group_2 Even though Group_2_decimal is a unique component n
78. The DEFINE directive allows you to assign a value to an identifier The UNDEFINE directive will remove the value The representation of this value stays in force until a corresponding UNDEFINE directive or the end of the source module is encountered 16 5 Record Dependency Relationships in CDD Repository By using the ZINCLUDE FROM CDD or the REPORT DEPENDENCY directives in conjunction with the DEPENDENCY_DATA qualifier in the BASIC command you can record dependency relationships in a CDO dictionary between a compiled module entity and included records or other referenced dictionary entities See Chapter 21 for more information about record dependency relationships 16 12 Compiler Directives 17 Data Representation This chapter describes how HP BASIC represents data stored in memory The following sections discuss four types of data representation integer float decimal and string 17 1 Integer Format 17 1 1 There are four ways in which integer data can be represented depending on the size of the data to be stored byte word longword and quadword Negative integer values are stored in two s complement format The following sections describe each of these formats Byte Length Integer Format Byte length integers are in the range 128 to 127 and are stored as 1 byte 8 bits starting on an arbitrary byte boundary Bits are labeled from the right 0 to 7 as in Figure 17 1 Figure 17 1 Byte Length Integ
79. The PC is within a routine that was compiled without the DEBUG compiler command qualifier or with NODEBUG e The source file was moved to a different directory after it was compiled the location of source files is embedded in the object modules Use the SET SOURCE command to direct the debugger to the new location 3 4 Controlling and Monitoring Program Execution This section discusses the following e Starting and resuming program execution with the GO command e Stepping through the program s code with the STEP command e Determining the current location of the program counter PC with the SHOW CALLS command e Suspending program execution with breakpoints e Tracing program execution with tracepoints e Monitoring changes in variables with watchpoints 3 4 1 Starting and Resuming Program Execution There are two commands for starting or resuming program execution GO and STEP The GO command starts execution The STEP command lets you execute a specified number of source lines or instructions 3 4 Using the OpenVMS Debugger with BASIC GO Command The GO command starts program execution which continues until forced to stop You will probably use the GO command most often in conjunction with breakpoints tracepoints and watchpoints If you set a breakpoint in the path of execution and then enter the GO command or press the keypad comma key that executes the GO command execution will be suspended when the program reaches that b
80. The program contains a language feature that is not recommended for new program development for example the FIELD statement This error is reported only when the FLAG DECLINING qualifier is in effect User Action Use 1 MAP MAP DYNAMIC and REMAP statements instead of FIELD 2 EDIT rather than CVT and 3 overlaid MAPs rather than CVTxx functions LANFEAINC language feature incompatible with BASIC PLUS 2 Explanation INFORMATION The program contains syntax that results in different behavior under HP BASIC and PDP 11 BASIC PLUS 2 for example opening a terminal format file This error is reported only when the FLAG BP2COMPATIBILITY qualifier is in effect User Action None A 50 Compile Time Error Messages LANFEAINH language feature inhibits optimization Explanation INFORMATION A program compiled with the NOSETUP qualifier contains a language feature that requires SETUP for example the RESUME statement The compilation continues with SETUP in effect User Action None The program must be compiled with SETUP in effect for the language feature to work LANFEANOT language feature not available in BASIC PLUS 2 Explanation INFORMATION The program contains a language element that is not supported in BASIC PLUS 2 for example RECORD statements This error is reported only when the FLAG BP2COMPATIBILITY qualifier is in effect User Action If the program must run under both HP BASIC and PDP 11 BASIC PL
81. This option permits the compiler to generate any EV4 instruction any instructions contained in the BWX and MAX extensions plus any instructions added for the EV6 chip These instructions include a floating point square root instruction SQRT integer floating point register transfer instructions and additional instructions to identify extensions and processor groups Programs compiled with this option might incur emulation overhead on EV4 EV5 EV56 and PCA56 processors ARCHITECTURE EV67 generates instructions for the EV67 processor 21264A Alpha chip This option permits the compiler to generate any EV6 instruction plus bit count instructions CTLZ CTPOP and CTTZ However HP BASIC does not generate any of the bit count instructions so EV67 is essentially identical to EV6 Programs compiled with this option might incur emulation overhead on EV4 EV5 EV56 and PCA56 processors ARCHITECTURE ITANIUM2 generates instructions for the Itanium 2 processor This option permits the compiler to generate any Itanium 2 instructions ARCHITECTURE MERCED generates instructions for the Merced processor This option permits the compiler to generate any Merced instructions Developing HP BASIC Programs 2 5 str lit NOJAUDIT file specification NOAUDIT default The AUDIT qualifier causes the compiler to include a history entry in CDD Repository when extracting a CDD Repository definition You can specify either a st
82. UNSIGNED WORD Cl WORD WORD VALUE Cl END GROUP c1 LONG MY LONG SIGNED LONGWORD Cl GROUP MY ULONG UNSIGNED LONGWORD Cl LONG LONG VALUE Cl END GROUP i Cl END RECORD Using CDD Repository with BASIC 21 23 SBASIC I CDDSUBGRO 1 data type in CDD Repository not supported substituted group for BASICINT MY UBYTE SBASIC I CDDSUBGRO 1 data type in CDD Repository not supported substituted group for BASICINT MY_UWORD SBASIC I CDDSUBGRO 1 data type in CDD Repository not supported substituted group for BASICINT MY_ULONG When the previous data definition is extracted from CDD Repository HP BASIC signals an informational message for each of the unsigned data types and names the CDD Repository unsigned byte field BYTE_VALUE the CDD Repository unsigned word field WORD_VALUE and the CDD Repository unsigned longword field LONG_VALUE HP BASIC does not support OCTAWORD integers If a CDD Repository defi nition contains an OCTAWORD integer HP BASIC signals the informational message Datatype in CDD Repository not supported substituted group for lt field name gt and creates a group to contain the field and a string component within the group The string component is 16 bytes for OCTAWORD integers For example CDDL Definition define record CDD top basic bigintegers description is Test of quadword and octaword integer data types basicint structure my quad datatype is signed quadword my octa datatype is si
83. Using CDD Repository with BASIC Suppose the HP BASIC program DOG_REPORT BAS contains the following directive SREPORT DEPENDENCY DISK1 CDDPLUS BASIC SMITH DOG DATABASE Use the DEPENDENCY_DATA qualifier when you compile the program BASIC DEPENDENCY DATA DOG REPORT After the compilation the dictionary contains the following CDO gt DIR Directory DISK1 CDDPLUS BASIC SMITH BREED 1 FIELD CALL_NAME 1 FIELD DOG_REPORTS MAIN 1 CDDSCOMPILED_MODULE DOG DATABASE 1 CDDS DATABASE DOG_INFORMATION 1 CDD RMS DATABASE DOG REC 1 RECORD OWNER_NUMBER 1 FIELD REG DOG NAME 1 FIELD CDO gt SHOW USES DOG DATABASE Owners of DISK1 CDDPLUS BASIC SMITH DOG DATABASE 1 DISK1 CDDPLUS BASIC SMITH DOG_REPORTSMAIN 1 Type CDDSCOMPILED MODULE via CDDS COMPILED DEPENDS ON CDO gt SHOW USED BY DOG REPORTSMAIN Members of DISK1 CDDPLUS BASIC SMITH DOG REPORTS MAIN 1 DOG_REPORT Type CDDSFILE via CDDSIN FILE DISK1 CDDPLUS BASIC SMITH DOG DATABASE 1 Type CDDSDATABASE via CDD COMPILED DEPENDS ON 21 5 Specifying a CDD History List Entry When your HP BASIC program accesses CDD Repository you have the option of entering a history list entry in the database The history list entry provides a history of users that access CDD Repository You create a history list entry by specifying the DCL command qualifier AUDIT For example BASIC DEPENDENCY DATA AUDIT History text goes here EX1 BAS Note that instead o
84. Variants A variant comprises two or more fields of a record that provide alternative descriptions for the same portion of a record 21 14 D FLOATING G FLOATING SIGNED LONGWORD H_FLOATING The following is an example of a CDDL data definition containing variant fields and the corresponding HP BASIC RECORD statement CDDL Definition define record CDD top basic variant_example description is test simple variant variant_example structure my_string datatype text size 9 variants variant my_s_real datatype my d real datatype end variant variant my g real datatype my h real datatype end variant end variants my byte datatype end variant example structure end variant_example Using CDD Repository with BASIC f floating d_floating g floating h_floating signed byte Translated RECORD Statement 1 INCLUDE FROM CDD CDDSTOP BASIC VARIANT EXAMPLE c1 test simple variant Cl RECORD VARIANT EXAMPLE UNSPECIFIED Cl STRING MY STRING 9 TEXT Cl VARIANT Cl CASE Cl SINGLE MY S REAL F FLOATING Cl DOUBLE MY D REAL D FLOATING Cl CASE Cl GFLOAT MY G REAL G FLOATING Cl HFLOAT MY H REAL H FLOATING Cl END VARIANT c1 BYTE MY BYTE SIGNED BYTE Cl END RECORD CDD Repository data definitions sometimes contain VARIANTS OF field description statements as well as simple variants A CDDL or CDO VARIANTS OF statement names a tag variable whose value at run time determines which
85. WHEN block or handler Explanation ERROR A DEF function definition is not allowed in a WHEN block or its associated handler User Action Remove the DEF function definition from within the WHEN block or handler DEFRESREF DEF lt name gt result reference illegal in this context Explanation ERROR The program attempts to assign a value to a DEF name outside the DEF block User Action Remove the assignment statement You cannot assign a value to a DEF outside of the DEF block DEFSIZNOT DEF lt name gt decimal size not as declared Explanation ERROR The DECIMAL d s size specified in the DEF statement does not match the DECIMAL d s used in the associated DECLARE DEF statement User Action Make the DECIMAL size specification agree in both the DECLARE DEF and DEF statements DEFSTAPAR DEF formal lt formal name gt inconsistent with usage outside DEF Explanation ERROR A DEF formal parameter has the same name as a program variable but different attributes User Action You should not use the same names for DEF parameters or program variables If you do you must ensure that they have the same data type and size DEFSTOOCMPX DEF lt name gt too complex to compile Explanation ERROR A DEF function uses too many temporary variables or parameters or is too complex to compile User Action Simplify and or break the function into smaller pieces DEFSTRPAR DEF string parameter is illegal in MAP DYNAMI
86. Z both uppercase and lowercase e The digits 0 to 9 e Special characters See the HP BASIC for OpenVMS Reference Manual for a complete list of the ASCII character set and character values The compiler does not distinguish between uppercase and lowercase letters except for letters inside quotation marks called string literals or letters in a DATA statement The compiler also does not process characters in a REM statement or comment field You can use nonprinting characters in your program for example in string literals and constants but to do so you must do one of the following e Use a predefined constant such as ESC or DEL e Use the CHR function to specify an ASCII value See Section 4 6 for more information about predefined constants See Chapter 10 for more information about the CHR function 4 4 Program Documentation Documenting a program is the process of putting explanatory text comments into your code to make the program more understandable Program documentation does not affect the way a program executes You can add comments throughout a program however programs that are neatly structured need fewer comments You can clarify your code by doing the following e Using meaningful variable names e Including sufficient white space e Indenting your program lines according to the structure of your code A comment field starts with an exclamation point and ends with another exclamation point or a carriage return The f
87. a dynamic string When a string variable is fixed length its length does not change regardless of the statement you use to modify it Table 11 1 provides more information about string modification Strings in virtual arrays have both fixed length and dynamic attributes String virtual arrays have a specified maximum length from 0 to 512 characters During program execution the length of an element in a string virtual array can change however the length is always from 0 to the maximum string size specified when the array was created See Section 11 4 and Chapter 13 for more information about virtual arrays String Handling 11 1 Table 11 1 String Modification Changes Made to Changes Made to Statement Fixed Length Strings Dynamic Strings LET Value Value and length LSET Value Value RSET Value Value Terminal I O Value Value and length Statements 1Terminal I O statements include INPUT INPUT LINE LINPUT MAT INPUT and so on 11 2 Using Dynamic Strings Although dynamic strings are less efficient than fixed length strings they are often more flexible For example to concatenate strings you can use the LET statement to assign the concatenated value to a dynamic string variable without having to be concerned about HP BASIC truncating the string or adding trailing spaces to it However if the destination variable is fixed length you must make sure that it is long enough to receive the concatenated string or HP BASIC
88. a greater amount of data is available in memory at one time however it also increases the memory space needed for buffer allocation and the processing time required to search the bucket Conversely a small bucket size minimizes buffer requirements but increases the number of accesses to the storage device thereby decreasing the speed of operations It is recommended that you use the DCL command EDIT FDL to design files used in production applications where performance is a concern File Input and Output 13 35 13 8 2 BUFFER Clause The BUFFER clause applies to disk files of any organization In the case of sequential files the BUFFER clause sets the number of blocks read in on each disk access For relative and indexed files the BUFFER clause determines the number of I O buffers that are allocated In general the OpenVMS operating system supplies adequate defaults for all file types therefore the BUFFER clause is rarely necessary You can specify up to 127 buffers as either a positive or a negative number e If 0 lt BUFFER lt 127 RMS allocates enough space for the specified number of buckets e If 128 lt BUFFER lt 0 BASIC allocates the absolute value of the specified number of buffers e If BUFFER 0 BASIC allocates the process default for the particular file organization and device this value is usually adequate 13 8 3 CONNECT Clause The CONNECT clause can be used only on indexed files CONNECT lets you
89. a listing file specify the LISTING qualifier when you compile your HP BASIC program interactively For example BASIC LISTING prog name If the program is compiled as a batch job the listing file is created by default specify the NOLISTING qualifier to suppress creation of the listing file By default the name of the listing file is the name of the source program followed by the file type LIS You can include a file specification with the LISTING qualifier to override this default A compiler listing generated by the LISTING qualifier has the following major sections e Source Program Listing The source program section contains the source code and line numbers generated by the compiler e Cross Reference The cross reference section is present if the CROSS_REFERENCE qualifier was specified It contains cross references of variables symbols and so forth e Allocation Map The allocation map section contains summary information about program sections variables and arrays e Qualifier Summary The qualifier summary section lists the qualifiers used with the BASIC command and the compilation statistics e Machine Code The machine code section is present if the MACHINE_CODE qualifier was specified It contains a symbolic representation of the machine instructions generated for the program section Developing HP BASIC Programs 2 21 2 2 Linking an HP BASIC Program On OpenVMS systems the OpenVMS Linker link
90. a subprogram Each time you call a subprogram HP BASIC positions the data pointer at the beginning of the subprogram s data The data pointer in the main program is not affected by READ or RESTORE statements in the subprogram in contrast with the RESTORE statement which resets record pointers to the first record in the file no matter where it is executed Chapter 5 contains more information about the READ and RESTORE statements For more information about the RESTORE statement see Chapter 13 SUB Subprograms A SUB subprogram is a program module that can be separately compiled and that cannot return a value A SUB subprogram is delimited by the SUB and END SUB statements You may use the EXTERNAL statement to explicitly declare the SUB subprogram 12 2 Program Segmentation 12 1 2 The END SUB statement does the following e Marks the end of the SUB subprogram e Does not affect I O operations or files e Releases the storage allocated to local variables e Returns control to the calling program The EXIT SUB statement transfers control to the statement lexically following the statement that invoked the subprogram It is equivalent to an unconditional branch to an END SUB statement The following SUB subprogram sorts two integers If this SUB statement is invoked with actual parameter values that are already in sorted order the EXIT SUB statement is executed and control returns to the calling program SUB sort_out INTEG
91. a value of one Ifthe specified starting position is less than or equal to 1 POS returns a value of one Ifthe specified starting position is greater than one and less than or equal to the string s length plus 1 POS returns the specified starting position Note that searching for a null string is not the same as searching for the null character A null string has a length of zero while the null character has a length of one The null character is an ASCII character whose value is zero 11 6 3 SEG Function The SEG function extracts a segment substring from a string The original string remains unchanged In the following example time is the input string 13 is the position of the first character extracted and 16 is the position of the last character extracted SEG time 13 16 SEG extracts from the input string the substring that starts at the first character position up to and including the last character position It returns the extracted segment PRINT SEG ABCDEFG 3 5 END 11 12 String Handling Output CDE If you specify character positions that exist in the string the length of the returned substring always equals int exp2 int exp1 1 Keep these considerations in mind when you use SEG e Ifthe starting character position is less than 1 HP BASIC assumes a value of 1 e Ifthe starting character position is greater than the ending character position or the length of the string SE
92. an invalid value for a keyword User Action Supply a valid value BASICHLB BASIC s HELP library is not installed on this system Explanation INFORMATION A HELP command was entered and the HP BASIC HELP library was not available User Action See your system manager BIFREQNUM built in function requires numeric expression Explanation ERROR A reference to an HP BASIC built in function contains a string instead of a numeric expression User Action Supply a numeric expression BIFREQSTR built in function requires string expression Explanation ERROR The program specifies a numeric expression for a built in function that requires a string argument User Action Supply a string expression for the built in function BLTFUNNOT built in function not supported Explanation ERROR The program contains a reference to a built in function not supported by this version of HP BASIC User Action Remove the function reference BOTBOUSPE bottom boundary must be less than the top boundary Explanation ERROR In a statement that specifies a viewport or windowsize you specified a bottom boundary that is greater than or equal to the corresponding top boundary User Action Correct the bottom boundary so that it is less than the top boundary BOUCANNOT bound cannot be specified for array Explanation ERROR An EXTERNAL statement declaring a SUB or FUNCTION subprogram specifies bounds in an array parameter for exa
93. and compiles the text as if it were placed in the position of the INCLUDE directive SINCLUDE DMB TEST FROM LIBRARY SYS LIBRARY BASIC_LIB TLB BASIC supplies the text library BASIC STARLET located in SYS LIBRARY This text library contains condition codes and other symbols defined in the system object and shareable image libraries Using the definitions from BASIC STARLET allows you to reference condition codes and other system defined symbols as local rather than global symbols To create your own text libraries using the OpenVMS Librarian utility see the VMS Librarian Utility Manual All file specifications CDD Repository path specifications text modules and library specifications must be string literals enclosed in quotation marks Compiler Directives 16 7 The source files accessed with INCLUDE cannot contain line numbers This requirement means that all statements in the accessed file are associated with the BASIC line containing the INCLUDE directive if line numbers are being used Therefore if you are using line numbers a INCLUDE directive cannot appear before the first line number in a source program A file accessed by INCLUDE can itself contain a INCLUDE directive When a program is compiled BASIC inserts the included text at the point at which it encounters the INCLUDE directive The compilation listing identifies any text obtained from an included file by placing a mnemonic in the first character position
94. and evolution It is comprised of a set of commands that enable you to manage files of an ongoing project For more information about CMS see the Guide to Source Code Analyzer for VMS Systems C 4 Optional Programming Productivity Tools A ABORT directive 16 10 ABS function 10 2 Addition of matrices 6 20 Address expression with DEPOSIT debugger command 3 12 with EXAMINE debugger command 3 11 with SET BREAK debugger command 3 7 with SET TRACE debugger command 3 9 Ampersand amp in comment field 4 6 ANALYSIS_DATA qualifier 2 3 ANSI D formatted file 18 2 ANSI tape files accessing 18 3 ARCHITECTURE qualifier 2 4 Arrays 4 10 4 11 6 1 to 6 23 as part of a record buffer 6 7 bounds 6 8 bounds of CDD Repository 2 11 CDD Repository 21 12 creating explicitly 6 2 to 6 7 creating implicitly 6 7 to 6 8 creating virtual array files 13 14 descriptors of 17 11 FORTRAN 19 9 input 6 9 to 6 19 matrix 6 1 of fixed length strings 6 6 Index Arrays cont d of RECORD instances 8 3 output 6 9 to 6 19 redimensioning with DIM statement 6 5 referencing 6 3 6 7 sharing among program modules 6 6 subscripts 6 1 to 6 2 vector 6 1 within a RECORD 8 4 zero based 6 1 ASCII character set 4 5 ASCII function 10 6 Assignment of matrices 6 19 Asterisk with PRINT USING statement 14 8 AUDIT qualifier 2 6 21 11 BASIC ANALYSIS_DATA 2 3 ARCHITECTURE 2 4 A
95. array implicitly then redimension the array with an executable DIM statement The DIM statement must execute before any reference to the array An array name cannot appear in a declarative statement after the array has been implicitly declared by a reference The following DECLARE statement is therefore illegal and causes HP BASIC to signal the compile time error illegal multiple definition of name NEW_ARRAY new_array 5 5 5 1 DECLARE LONG new_array 15 10 5 6 4 Determining the Bounds of an Array BASIC provides two built in functions LBOUND and UBOUND that allow you to determine the lower and upper bounds respectively for any dimension in an array The following example sets up four variables that contain the lower and upper bounds of both dimensions of the array Sales_data These variables represent the years and months for which there is sales data available The two FOR NEXT loops print all the sales information in the array starting with the first year and month and ending with the last year and month 6 8 Arrays DECLARE Sales data 1900 TO 1999 1 TO 12 Month start LBOUND Sales data 2 Year start LBOUND Sales data 1 Month end UBOUND Sales data 2 Year end UBOUND Sales data 1 FOR Years Year_start TO Year_end FOR Month Month_start TO Month ends PRINT Sales data Year Month NEXT Month NEXT Year Note You cannot implicitly declare arrays with the LBOUND and UBO
96. be naturally aligned because the size of each record element is not a multiple of the record s natural alignment This error is reported only when the WARNING ALIGNMENT qualifier is in effect User Action Modify the size of the record to be a multiple of the record s natural alignment ELSIMPCON ELSE appears in improper context ignored Explanation ERROR The program contains an ELSE clause that either is not preceded by an IF statement or that appears after an IF has been terminated with a line number or END IF User Action Remove either the ELSE clause or the terminating line number or END IF EMPTYOBJ Empty object file due to error Explanation INFORMATION The compiler has detected errors and therefore did not produce an object file User Action The errors must be corrected before the compiler will produce an object file ENDIMPCON END IF appears in improper context ignored Explanation ERROR The program contains an END IF statement that either is not preceded by an IF statement or occurs after an IF has been terminated by a line number User Action Supply an IF statement or remove the terminating line number ENDSTAREQ END statement required in ANSI Explanation INFORMATION A program compiled with the ANSI_ STANDARD qualifier does not contain an END statement User Action Include an END statement as the last statement in the program ANSI Minimal BASIC requires an END statement A 26 Compil
97. called a PSECT Any HP BASIC subprogram can access the values in a common area by specifying a common with the same name An item in a COMMON statement can be any one of the following e Numeric variable e Numeric array e Fixed length string variable e Array of fixed length strings e RECORD instance e FILL item e RFA item The amount of storage reserved for a variable depends on its data type You can specify a length for string variables and string array elements that appear in a COMMON statement If you do not specify a length the default is 16 The following statement specifies 2 bytes for emp code 3 bytes for wage code and 22 bytes for dep code COMMON code STRING emp code 2 wage code 3 dep code 22 In a single program module multiple common areas with the same name allocate storage end to end in a single PSECT That is HP BASIC concatenates all common areas with the same name in the same program module in order of appearance For example the following statements allocate storage for five LONG integers in a single PSECT named into COMMON into LONG call_ count subl count sub2 count COMMON into LONG sub3 count sub4 count When you explicitly declare an array HP BASIC allows you to specify both upper and lower bound values The value you supply as the upper bound determines the maximum subscript value for a given dimension and the value you supply for the lower bound determines the minimum subscript value for a
98. conditional compilation Explanation ERROR The program references a line number that does not appear in the object code as a result of the branch taken in a IF THEN ELSE END IF directive User Action Change the IF THEN ELSE END IF directive or remove the line number reference LINOUTORDE Line numbers are out of order Explanation ERROR The line numbers in an Alpha BASIC program are not in ascending order User Action Reorder the line numbers and or statements in your program so that the line numbers are in ascending order LINREQTWO LINES output requires at least 2 X Y points Explanation ERROR A LINE graphic output statement specifies less than 2 points User Action Specify a minimum of 2 points in the LINE graphic output statement LNPNOTBP2 programs without line numbers are not allowed in BASIC PLUS 2 Explanation INFORMATION BASIC PLUS 2 does not support programs without line numbers This error is reported only when the FLAG BP2COMPATIBILITY qualifier is in effect User Action Add a line number to the first line of the program LOGOPENON logical operation on noninteger quantity Explanation ERROR The program contains a logical operation performed on strings or real numbers User Action Change the logical operands to integers LOOINDMUS loop control variable must be a numeric variable Explanation ERROR A FOR statement specifies a string variable as the loop control variable
99. contain that field For more information about how HP BASIC translates CDD Repository data types see Section 21 9 21 3 Using CDD Repository with BASIC When dependency recording is in effect the compiler updates the CDO format dictionary to show what dictionary data entities are used by the program the data dependencies created by the compilation To take advantage of dependency recording do the following e Use either or both of the HP BASIC lexical directives INCLUDE FROM CDD and REPORT DEPENDENCY in the source program to define the dependency relationships you want to create between your program and definitions in the CDO format dictionary e Establish a CDO format dictionary called CDD DEFAULT e Include the DEPENDENCY_DATA qualifier in the BASIC command that compiles the module 21 3 1 DEPENDENCY_DATA Qualifier When you compile a program that references CDO format data definitions you can include the qualifier in the BASIC command line The DEPENDENCY_ DATA qualifier instructs the compiler to create dependency relationships as defined in the program by INCLUDE and REPORT directives and update the dictionary to show those relationships To prevent update of the dictionary specify the default NODEPENDENCY_ DATA The compiler can extract record definitions from the dictionary as specified by INCLUDE FROM CDD directives in the program but not update the dictionary The compilation does not add compiled m
100. decimal point is less than or equal to the total number of digits DECSIZOUT DECIMAL size specification out of range Explanation ERROR The declaration for a packed decimal variable or variable specifies more than 31 digits User Action Change the declaration to specify 31 or fewer digits DEFEXPCOM expression with DEF too complex moving lt name gt invocation Explanation WARNING A DEF is being invoked from within a complex expression To simplify the expression the compiler will evaluate the DEF s first Alpha BASIC only User Action Rewrite statement into simpler expressions DEFINVNOT DEF invocation not allowed in assignment context Explanation ERROR A DEF function invocation including a parameter list appears on the left side of an assignment statement User Action Remove the assignment statement You cannot assign values to a function invocation DEFMODNOT DEF lt name gt mode not as declared Explanation ERROR The specified data type in a function declaration disagrees with the data type specified in the function definition User Action Make the data type specifications match in both the function declaration and the function definition DEFNOTDEF DEF lt name gt not defined Explanation ERROR The program contains a reference to a nonexistent user defined function User Action Define the function in a DEF statement Compile Time Error Messages A 21 DEFNOTWHE DEF not allowed in
101. displays data with the PRINT statement is often limited For example a program might use floating point numbers to represent dollars and cents The PRINT statement displays floating point numbers with up to six digits of accuracy and places the decimal point anywhere in that 6 digit field In contrast PRINT USING lets you display floating point numbers in the following ways e Rounded to a number of specified decimal places e Vertically aligned on the decimal point e Preceded by a dollar sign e With commas every third digit to the left of the decimal point Formatting monetary values in this way provides a more readable report Another use for formatted numeric values might be to print checks on a printer PRINT USING lets you print numbers with a dollar sign and an asterisk filled field preceding the first digit PRINT USING also formats string data With it you can left and right justify string expressions or center a string expression over a specified column position Further the PRINT USING statement can contain string literals These are strings that do not control the format of a print item but instead are printed exactly as they appear in the format string Formatting Output with the PRINT USING Statement 14 1 It is recommended that you declare all format expressions as string constants When you do this the HP BASIC compiler instructs the Run Time Library to compile the string at compile time rather than at run time thus imp
102. ends the first format field after the third character HP BASIC continues to scan the format string searching for a character that begins a format field The first such character is the number sign at character position 7 Therefore the characters at positions 4 5 and 6 are treated as a string literal The characters at positions 7 8 and 9 make up a second valid numeric format field PRINT USING ABC 123 345 14 2 Formatting Output with the PRINT USING Statement Output 123ABC345 When the statement executes HP BASIC prints the first number in the list using the first format field then prints the string literal ABC and finally prints the second number in the list using the second format field If you were to supply a third number in the list HP BASIC would reuse the first format string This is called reversion PRINT USING ABC H 123 345 564 Output 123ABC345 564ABC Because any character not part of a format field is printed just as it appears in the format field you can use a space or multiple spaces to separate format fields in the format string as shown in the following example DECLARE STRING CONSTANT format string DECLARE SINGLE A B A 2 565 B 100 350 PRINT USING format_string A B A B Output 2 57 100 35 2 57 100 35 When the HP BASIC compiler encounters the PRINT USING statement HP BASIC prints the value of A rounded according to PRINT USING rules three space
103. error handling is in effect a program will abort when division by zero is attempted because division by zero is an error of SEVERE severity With an error handler you can include an alternative set of instructions for the program to follow if the zero was input at a terminal a user written error handler could display a Try again message and execute the program lines again requesting input 15 2 User Supplied Error Handlers It is good programming practice to anticipate certain errors and provide your own error handlers for them User written error handlers allow you to handle errors for a specified block of program statements as well as complete program units Any program module can contain one or more error handlers These error handlers test the error condition and include statements to be executed if an error occurs To provide your own error handlers you use WHEN ERROR constructs A WHEN ERROR construct consists of two blocks of code a protected region and a handler A protected region is a block of code that is monitored by the compiler for the occurrence of an error A handler is the block of code that receives program control when an error occurs during the execution of the statements in the protected region There are two forms of WHEN ERROR constructs in both cases the protected region begins immediately after a WHEN ERROR statement The following partial programs illustrate each form In Example 1 the handler is attached t
104. especially useful when the program contains many variables or when someone else is running your program For example INPUT PLEASE TYPE 3 INTEGERS B C D A B C D PRINT THEIR SUM IS A END Simple Input and Output 5 1 Output PLEASE TYPE 3 INTEGERS 25 50 75 Retum THEIR SUM IS 150 When your program runs BASIC stops at each INPUT LINPUT or INPUT LINE statement prints a string prompt if specified and an optional question mark followed by a space it then waits for your input By using either a comma or semicolon you can affect the format of your string prompt as follows e If you have a semicolon separating the input prompt string from the variable BASIC prints the question mark and space immediately after the input prompt string e If you have a comma separating the input prompt string from the variable BASIC prints the input prompt string skips to the next print zone and then prints the question mark and space See Section 5 2 1 for more information about print zones For more information about formatting string prompts see Section 5 1 1 3 You must provide one value for each variable in the INPUT request If you do not provide enough values BASIC prompts you again For example INPUT A B END Output 5 Return 6 Return BASIC interprets a carriage return null input as a zero value for numeric variables and as a null string for string variables For exam
105. file spec The name of the file you want to execute The following example executes the image SAMPLE EXE without invoking the debugger RUN SAMPLE NODEBUG See Chapter 3 for more information about debugging programs During program execution an image can generate a fatal error called an exception condition When an exception condition occurs HP BASIC displays an error message Run time errors can also be issued by other facilities such as the OpenVMS operating system For more information about run time errors see Appendix B 2 3 1 Improving Run Time Performance of HP BASIC Programs Even with fast hardware and an optimizing compiler you can still tune your code for run time performance This section provides recommendations to consider if further performance improvements are desirable To achieve the best performance for your application it is important to let both the hardware and the optimizer code generator take advantage of their full capabilities This can be accomplished by minimizing and in some cases avoiding the use of language features and qualifiers that block optimal program execution 2 28 Developing HP BASIC Programs 2 3 1 1 Data Items Choose data types and align data items with the following in mind Align data items in MAP COMMON and RECORD statements This is the recommended first step to improve performance For more information on alignment see Section 2 1 2 under WARNING ALIGNMENT Use LONG or QU
106. following example the PRINT statement displays the Rig component in the Specifications group in the variable named My_yacht The RECORD instance name qualifies the group name and the group name qualifies the elementary RECORD component The elementary component name qualified by all intermediate group names and by the RECORD instance name is called 8 8 Creating and Using Data Structures a fully qualified component The full qualification of a component is called a component path name DECLARE Yacht My_ yacht PRINT My yacht Specifications Rig Because it is cumbersome to specify the entire component path name BASIC allows elliptical references to RECORD components GROUP names are optional in the component path name unless e A RECORD contains more than one component with the same name e The GROUP is an array The rules for using elliptical references are as follows e You must always specify the RECORD instance that is the name of the declared variable e You must always specify any dimensioned group e You may omit any other intermediate component names e You must specify the final component name The following example shows that using the complete component path name is valid but not required The assignment statement uses the fully qualified component name the PRINT statement uses an elliptical reference to the same component omitting Hxtended_family and Nuclear_family GROUP names Note that the Children GROUP name i
107. have read access to the record That is other users can retrieve the record but cannot perform DELETE PUT or UPDATE operations on it ALLOW MODIFY lets other access streams perform GET DELETE or UPDATE operations on the record If you are trying to access a locked record BASIC signals Record bucket locked ERR 154 However if you only need to read this record you can override the lock with the REGARDLESS clause The REGARDLESS clause allows you to read a locked record Use caution when using the REGARDLESS clause because a record accessed in this way might be in the process of being changed by another program Alternatively you can also specify the WAIT clause on a GET statement the WAIT clause allows you to handle record locked conditions by waiting for the record to become available Note that if a WAIT clause is specified on a GET operation to a unit record device such as a terminal the integer expression indicates how long to wait for the I O to complete rather than how long to wait on a record locked condition For more information see Section 13 6 9 13 18 File Input and Output 13 6 5 Writing Records For a file opened with ACCESS WRITE or ACCESS MODIFY the PUT statement moves data from the record buffer to a file using the I O buffer PUT statements are valid on RMS sequential relative and indexed files You cannot use PUT statements on terminal format files or virtual array files Sequential access is valid on
108. indexed file and specify a bucket size other than that originally assigned to the file BASIC signals the error File attributes not matched ERR 160 13 34 File Input and Output Records cannot span bucket boundaries Therefore when you specify a bucket size in your program you must consider the size of the largest record in the file Note that a bucket must contain at least one record Buckets in both relative and indexed files contain information in addition to the records stored in the bucket You should take this into consideration There are two ways to establish the number of blocks in a bucket The first is to use the default The second is to specify the approximate number of records you want in each bucket A bucket size based on that number is then calculated The default bucket size assigned to relative and indexed files is as small as possible A small bucket size however is rarely desirable A default bucket size is selected depending on the e Record length e File organization relative or indexed e Record format If you do not define the BUCKETSIZE clause in the OPEN statement BASIC does the following e Assumes that there is a minimum of one record in the bucket e Calculates a size e Assigns the appropriate number of blocks Note that when you specify a bucket size for files in your program you must keep in mind the space versus speed tradeoffs A large bucket size increases file processing speed because
109. initial values are reset each time the DIM statement is executed Arrays 6 5 In the following example the second DIM statement reinitializes the array real_array therefore real_array 1 equals zero in the second PRINT statement X 10 Y 20 DIM real array X real array 1 100 PRINT real array 1 DIM real array Y PRINT real array 1 END Output 100 0 You cannot reference an array named in an executable DIM statement until after the DIM statement executes If you reference an array element declared in an executable DIM statement whose subscripts are larger than the bounds specified in the last execution of the DIM statement BASIC signals the run time error Subscript out of range ERR 55 provided subscript checking is enabled 6 2 3 Creating Arrays with the COMMON Statement Create arrays with the COMMON statement when you need an array of fixed length strings or when you want to share an array among program modules Program modules can share arrays in COMMON statements by defining a common block with the same name The COMMON statements in the following programs create a 100 element array of fixed length strings each element 10 characters long Because the main program and subprograms use the same common name the storage for these arrays is overlaid when the programs are linked therefore both programs can read and write data to the array Main Program COMMON ABC STRING access list 1 TO 1
110. it retrieves the next value in the data block BASIC signals an error if you do one of the following e Assign alphabetic characters to a numeric variable BASIC signals Data format error ERR 50 e Have more variables in the READ statements than there are values in the DATA statements BASIC signals Out of data ERR 57 BASIC ignores excess data in DATA statements The following example of READ and DATA mixes string and floating point data types The first READ statement reads the first data item in the program The circumference is The second READ statement reads the second data item 40 5 DATA The circumference is DATA 40 5 READ texts READ radius CIRCUMFERENCE PI radius 2 PRINT text CIRCUMFERENCE END Output The circumference is 254 469 5 1 2 2 RESTORE Statement The RESTORE statement lets you read the same data more than once It has no effect without READ and DATA statements RESTORE resets the data pointer to the beginning of the first DATA statement in the program unit You can then read data values again Consider the following program 10 READ B C D 20 RESTORE 30 READ E F G 40 DATA 6 3 4 7 9 2 50 END The READ statement in line 10 reads the first three values in the DATA statement B 6 C 3 D 4 Simple Input and Output 5 7 The RESTORE statement resets the pointer to the beginning of line 40 During the second READ statement line 30 the first three values are rea
111. know that the program did not end correctly WHEN ERROR USE error_handler Y CTRLC END WHEN HANDLER error_handler IF ERR 28 THEN PRINT 1 Abort END HANDLER Note When you trap Ctrl C with an error handler your program might be in an inconsistent state therefore you should handle the Ctrl C error and exit the program as quickly as possible ECHO and NOECHO Functions The NOECHO function disables echoing on a specified channel Echoing is the process by which characters typed at the terminal keyboard appear on the screen If you specify channel 0 your terminal as the argument the characters typed on the keyboard are still accepted as input however they do not appear on the screen The ECHO function enables echoing on a specified channel and cancels the effect of the NOECHO function on that channel 10 16 Functions 10 1 6 3 If you do not use these functions ECHO is the default The following program shows a password routine in which the password does not echo Y NOECHO 03 INPUT PASSWORD pword IF pword PLUGH THEN PRINT THAT IS CORRECT END IF Y ECHO 03 END Note that the Y ECHO 0 statement is necessary to turn the echo back on If this statement were not included then all subsequent user inputs would not echo to the terminal screen INKEY Function The INKEY function reads a single keystroke from a terminal opened on a specified channel and returns the typed char
112. lock_status_block NA lock_value_block NA logical_name STRING longword_signed LONG continued on next page Using BASIC in the Common Language Environment 19 15 Table 19 4 Cont OpenVMS Usages OpenVMS Usage BASIC Implementation longword_unsigned mask_byte mask_longword mask_quadword mask_word null_arg octaword_signed octaword_unsigned page_protection procedure process_id process_name quadword_signed quadword_unsigned rights_holder rights_id rab section_id section_name system_access_id time_name uic user_arg varying_arg vector_byte_signed vector_byte_unsigned LONG BYTE LONG QUAD WORD A null argument is indicated by a comma used as a placekeeper in the argument list BASIC OCTAWORD BASIC OCTAWORD LONG EXTERNAL LONG FUNCTION proc LONG STRING QUAD QUAD QUAD LONG NA QUAD STRING QUAD STRING LONG LONG Dependent upon application BYTE array n BYTE array n 2Although unsigned data structures are not directly supported in BASIC you can substitute the signed equivalent provided you do not exceed the range of the signed data structure 3The definition of the RECORD structures are included in the HP BASIC system definitions text library See Section 19 4 4 for more information continued on next page 19 16 Using BASIC in the Common Language Environment 19 4 4 Table 19 4 Cont OpenVMS Usages OpenVMS Usage BASIC Implementation ve
113. lt name gt with nonstring datatype Explanation ERROR The suffix is only allowed on string data types User Action Remove the suffix from the variable name or change the data type keyword CDDSUBGRO substituted GROUP for lt field name gt Data type in CDD Repository not supported Explanation INFORMATION The CDD Repository definition specifies a data type that is not native to HP BASIC HP BASIC creates a GROUP with the same name as the CDD Repository field and creates variable names for the GROUP components User Action None CDDTAGIGN tag value ignored for lt field name gt from CDD Repository Explanation INFORMATION The CDD Repository record definition contains a VARIANTS OF User Action None HP BASIC translates the VARIANTS OF as if it were a regular variant however the tag value is ignored Compile Time Error Messages A 15 CDDUNSDAT data type specified in CDD Repository for lt field name gt not supported Explanation ERROR The data type specified for a field is not supported by HP BASIC User Action Change the data type in the CDD Repository record definition CDDUPPBOU upper bound omitted for dimension lt number gt of lt array name gt Explanation ERROR An array in a CDD Repository definition does not specify an upper bound User Action Specify an upper bound in the CDD Repository definition CDDVARFLD field lt name gt from CDD Repository has variable offset or length
114. map variables do not change the actual records in the file To transfer the changed variables to the file you must use the PUT or UPDATE statement For more information see Chapter 13 The following program example uses map variables to access fields in payroll records 7 6 Data Definition WHEN ERROR USE eof_handler DECLARE INTEGER CONSTANT EOF 11 MAP PAYROL STRING emp name LONG wage class amp STRING sal_rev date SINGLE tax_ytd OPEN payroll dat FOR INPUT AS FILE 4 amp ORGANIZATION SEQUENTIAL amp ACCESS READ amp MAP PAYROL OPEN payrol new FOR OUTPUT AS FILE 5 amp ORGANIZATION SEQUENTIAL amp ACCESS WRITE amp MAP payrol PRINT PAYROLL VERIFICATION get_loop WHILE 1 1 PRINT emp name wage class sal rev date tax ytd PRINT YOU CAN CHANGE Zoo PRINT 1 EMPLOYEE NAME PRINT 2 WAGE CLASS PRINT 3 REVIEW DATE PRINT 4 TAX YEAR TO DATE PRINT 5 DONE read loop WHILE 1 1 INPUT CHANGES ANSWER WITH YES OR NO chng IF chng NO THEN ITERATE get loop ELSE INPUT NUMBER number END IF Data Definition 7 7 SELECT numbers CASE CASE CASE CASE CASE CASE 1 INPUT EMPLOYEE NAME emp name 2 INPUT WAGE CLASS wage_class 3 INPUT REVIEW DATE sal_rev_date 4 INPUT TAX YEAR TO DATE tax_ytd 5 EXIT read_loop ELSE PRINT Invalid response please try again END SELECT NEXT PUT 5 NEXT END WHEN HANDLER e
115. more items or no items Do not type the brackets on the command line However you must include the brackets in the syntax for OpenVMS directory specifications and for a substring specification in an assignment statement In command format descriptions vertical bars separate choices within brackets or braces Within brackets the choices are optional within braces at least one choice is required Do not type the vertical bars on the command line In command format descriptions braces indicate required choices you must choose at least one of the items listed Do not type the braces on the command line Bold type represents the introduction of a new term It also represents the name of an argument an attribute or a reason Italic type indicates important information complete titles of manuals or variables Variables include information that varies in system output Internal error number in command lines PRODUCER name and in command parameters in text where dd represents the predefined code for the device type Uppercase type indicates a command the name of a routine the name of a file or the abbreviation for a system privilege numbers angle array chnl chnl exp com cond cond exp const data type decimal var decl item def delim equiv name err num exp ext routine external param file spec func int int const int exp int var A hyphen at the end of a command format description
116. not to generate a compiled module entity NO DIAGNOSTICS file spec NODIAGNOSTICS default The DIAGNOSTICS qualifier creates a diagnostics file containing compiler messages and diagnostic information The diagnostics file is used by LSE to display diagnostic error messages and to position the cursor on the line and column where a source error exists 2 8 Developing HP BASIC Programs Remarks e The Language Sensitive Editor LSE must be installed e If you do not supply a file specification with the DIAGNOSTICS qualifier the diagnostics file has the same name as its corresponding source file and the file type DIA All other file specification attributes depend on the placement of the qualifier in the command See the OpenVMS documentation set for more information e NODIAGNOSTICS specifies that no diagnostics file is created NO DECLINING NO FLAG ALL NONE FLAG NODECLINING default The FLAG qualifier lets you specify whether BASIC warns you about declining features Remarks e NOFLAG causes the compiler to issue no warnings about declining features e FLAG ALL is the same as FLAG DECLINING e FLAG NONE is the same as NOFLAG BYTE WORD LONG QUAD INTEGER_SIZE INTEGER_SIZE LONG default The INTEGER_SIZE qualifier lets you specify the default size for integer data Remarks e The default integer size LONG applies to all integer variables whose data type is not ex
117. not transfer control out of a DEF function except by way of an EXIT DEF or END DEF statement This means that e If the DEF function contains an ON ERROR GOTO GOTO ON GOTO GOSUB ON GOSUB or RESUME statement that statement s target line number must also be in that DEF function e An ON ERROR GO BACK statement can transfer control out of a DEF function however a RESUME statement in an error handler outside the DEF function cannot transfer control back into the DEF function e Ifthe DEF function contains a handler and was invoked from a protected region an EXIT HANDLER statement causes control to be transferred to the specified handler for that protected region However if the DEF function contains a handler but was not invoked from a protected region an EXIT HANDLER statement causes control to be transferred to the default error handler Functions 10 23 e A subroutine cannot be shared by more than one DEF function however if you rewrite the subroutine as a DEF function with no parameters other function definitions can share it A DEF function never changes the value of a parameter passed to it Also because formal parameters are local to the function definition you cannot access the values of these variables from outside the DEF statement These variable names are known only inside the DEF statement In the following example the variable first is declared only in the function fn_sum When HP BASIC sees the second PRINT s
118. number that starts the error handling code Otherwise the ON ERROR statement specifies the branch to be taken in the event of an error There are three forms of the ON ERROR statement e ON ERROR GOTO 0 The ON ERROR GOTO 0 statement reverts control to HP BASIC default error handling in one of two ways Ifan error is pending execution of the ON ERROR GOTO 0 statement returns control to the HP BASIC error handler immediately Ifno error is pending an ON ERROR GOTO 0 statement disables your current error handler The HP BASIC error handler handles all subsequent errors until another ON ERROR statement is executed unless an error occurs in a WHEN ERROR protected region e ON ERROR GOTO target The ON ERROR GOTO target statement reverts control to the target when subsequent errors occur that are not handled by WHEN block handlers Handling Run Time Errors 15 21 e ON ERROR GO BACK The ON ERROR GO BACK statement transfers control to the calling program s error handler if an error occurs in the subprogram or DEF function If you use ON ERROR GO BACK in a PROGRAM unit outside of a DEF function and no other outer protected region exists it is equivalent to ON ERROR GOTO 0 and HP BASIC default error handling is in effect With ON ERROR GO BACK if an error occurs in the execution of a function or subprogram the error is passed to either the error handler of the surrounding program module in the case of a DEF function definition
119. of text that appears on the first line of every page in the compilation listing This text line is a quoted string of up to 31 characters and normally contains the source program title and other information 16 2 Compiler Directives If the TITLE directive is the first source text in a module then the quoted string appears in the first line of every page of the compilation listing otherwise the quoted string appears in the first line of every subsequent page in the compilation listing That is if BASIC encounters a TITLE directive after it has begun creating a page in the output listing the title information will not appear on that page Rather it appears on all of the following pages until it encounters another TITLE directive TITLE must appear on its own line For example STITLE File OPEN Subprogram Author Hugh Ristics SUB FILSUB STRING F_NAME The SBTTL directive lets you specify a line of text that appears on the second line of every page in the compilation listing beneath the title If BASIC encounters a SBTTL directive after it has begun creating a page in the output listing the subtitle information will not appear on that page Rather it appears on all following pages until it encounters another SBTTL or TITLE directive If you want the subtitle to appear on the first page the SBTTL directive must appear directly after the TITLE directive Any number of SBTTL directives can appear in a source file thus y
120. of the decimal point BASIC fills the remaining spaces with zeros DECLARE STRING CONSTANT FM PRINT USING FM 15 72 PRINT USING FM 39 3758 PRINT USING FM 26 Output 15 720 39 376 26 000 If there are more fractional digits than reserved places to the right of the decimal point BASIC rounds the number to fit the reserved places Note that there must be enough places reserved to the left of the decimal point for the integer portion of the number Otherwise BASIC prints the number in PRINT format preceded by a percent sign The following example shows how PRINT USING rounds numbers when you specify decimal point location Formatting Output with the PRINT USING Statement 14 5 14 3 3 PRINT USING 25 789 PRINT USING 100 2 PRINT USING 999 END Output 25 79 100 2 1 00 BASIC fills all reserved spaces to the left of the decimal point with specified digits spaces or the minus sign PRINT USING 5 25 PRINT USING 5 25 PRINT USING 5 25 END Output 5 25 5 25 5 25 Printing Numbers with Special Symbols Special symbols let you print numbers with trailing minus signs asterisk fill fields floating currency symbols commas or E notation You can also specify debits credits leading zeros leading blanks and blank if zero fields Table 14 1 summarizes these special characters Table 14 1 Format Characters for Numeric Fields Character Effec
121. of the program This example indicates that execution is currently at line 18 of routine PRODUCT in module TEST which was called from line 47 of routine COUNTER in module TEST which was called from line 21 of routine MY_PROG in module MY_PROG 3 4 3 Suspending Program Execution The SET BREAK command lets you select breakpoints which are locations at which the program will stop running When you reach a breakpoint you can enter commands to check the call stack examine the current values of variables and so on A typical use of the SET BREAK command is shown in the following example DBG gt SET BREAK COUNTER DBG gt GO break at TEST COUNTER 34 SUB COUNTER LONG X Y DBG gt In this example the SET BREAK command sets a breakpoint on the subprogram COUNTER the GO command starts execution When the subprogram COUNTER is encountered execution is suspended the debugger announces that the breakpoint at COUNTER has been reached break at displays the source line 34 where execution is suspended and prompts you for another command At this breakpoint you can step through the subprogram COUNTER using the STEP command and use the EXAMINE command see Section 3 5 1 to check on the current values of X and Y When using the SET BREAK command you can specify program locations using various kinds of address expressions for example line numbers routine names instructions virtual memory addresses With high level la
122. of the variant fields is the current variant HP BASIC does not support the VARIANTS OF statement If a CDD Repository data definition containing a VARIANTS OF statement is extracted HP BASIC signals the informational message lt number gt tag value from CDD Repository ignored and treats the VARIANTS OF as an ordinary variant and ignores the tag value 21 8 NAME FOR BASIC Clause HP BASIC supports the CDDL and CDO field attribute clause NAME FOR BASIC The field attribute clause NAME FOR BASIC declares a facility specific name for a field For example name for basic is subject_name When you assign a name using the NAME FOR BASIC clause in a CDDL or CDO data definition HP BASIC recognizes only this name when you refer to the field Note that when you use the NAME FOR BASIC clause you can place dollar sign and percent sign suffixes in your RECORD statement field names The following example is a CDDL data definition containing the NAME FOR BASIC clause and the corresponding HP BASIC RECORD statement Using CDD Repository with BASIC 21 15 CDDL Definition define record city study description is This example formats data resulting from a study on the relationship between place of birth and earning potential info structure subject name datatype text size 10 B name for basic is subject name birth city datatype text size 10 name for basic is city of births salary datatype signed byte n
123. off errors by multiplying floating point values by 10 raised to the scale factor before storing them in variables It is ignored for all but VAX double precision DOUBLE floating point numbers Remarks The SCALE qualifier is provided for compatibility with existing programs and with other implementations of BASIC It is recommended that you do not use this feature for new program development Accumulated round off errors can be better controlled with packed decimal numbers See the HP BASIC for OpenVMS Reference Manual for more information about packed decimal numbers NO SEPARATE_COMPILATION NOSEPARATE_COMPILATION default The SEPARATE_COMPILATION qualifier causes the compiler to place indi vidual compilation units in separate modules in the object file NOSEPARATE_ COMPILATION the default groups individual compilation units in a source file as a single module in the object file When creating modules for use in an object library consider using SEPARATE_ COMPILATION to minimize the size of the routines included by the linker as it creates the executable image SEPARATE_COMPILATION also reduces the compiler virtual memory requirements when a source contains several compilation units Remarks e SEPARATE COMPILATION causes the compiler to place each routine in a separate module within the output object e NOSEPARATE_COMPILATION in most cases allows more interprocedu ral optimizations NO CDD_DEFINITIONS NOJENVI
124. on device 5 CANFINFIL Can t find file or account 7 IO_CHAALR I O channel already open 9 IO_CHANOT I O channel not open 10 PROVIO Protection violation 11 ENDFILDEYV End of file on device 12 FATSYSIO_ Fatal system I O failure 14 DEVHUNWRI Device hung or write locked 15 KEYWAIEXH Keyboard wait exhausted 18 ILLSYSUSA Illegal SYS usage 28 PROC__TRA Programmable C trap 29 CORFILSTR Corrupted file structure 31 ILLBYTCOU Illegal byte count for I O 35 MEMMANVIO Memory management violation 42 VIRBUFTOO Virtual buffer too large 43 VIRARRDIS Virtual array not on disk 45 VIRARROPE Virtual array not yet open 46 ILLIO_CHA Illegal I O channel 47 LINTOOLON Line too long 48 FLOPOIERR Floating point error or overflow 49 ARGTOOLAR Argument too large in EXP 50 DATFORERR Data format error 51 INTERR Integer error 52 ILLNUM Illegal number 53 ILLARGLOG Illegal argument in LOG 54 IMASQUROO Imaginary square roots continued on next page Run Time Messages B 31 Table B 1 Cont BASIC Run Time Errors Error Number Explanation 55 SUBOUTRAN Subscript out of range 56 CANINVMAT Can t invert matrix 57 OUTOF_DAT Out of data 58 ON_STAOUT ON statement out of range 59 NOTENODAT Not enough data in record 61 DIVBY_ZER Division by 0 63 FIEOVEBUF FIELD overflows buffer 64 NOTRANACC Not a random access device 66 MISSPEFEA Missing special feature 67 ILLSWIUSA Illegal switch usage 72 RETWITGO
125. one virtual array on the channel you must reduce the amount of storage used by the array However if there is more than one virtual array on the channel you can put each array on a separate channel VIRNOTALL virtual array not allowed in graphics statements Explanation ERROR You specified an entire virtual array on a statement that does not allow them User Action Specify a nonvirtual array in place of the virtual array VIRRECTOO virtual RECORD lt name gt is too large Limit is 512 bytes Explanation ERROR The elements of a virtual array are of type lt name gt and the total storage requirement for each element is greater than 512 bytes User Action Reduce the size of the RECORD WRITEERR error writing lt file name gt Explanation ERROR An error was detected in attempting to write to a file User Action Supply a valid file specification or take corrective action based on the associated message A 90 Compile Time Error Messages WROTYPLIB library lt lib name gt is not an OBJECT or IMAGE library Explanation WARNING The logical BASIC LIBn translates to a library that is not an object library or a shareable image library User Action Change the logical BASIC LIBn to translate to an object library or a shareable image library XYPOIREQ X Y point required between semicolons Explanation ERROR In a list of points in a statement such as PLOT LINES you specified two semicolons in a row without an
126. or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries Printed in the US ZK5424 This manual is available on CD ROM This document was prepared using DECdocument Version 3 3 1b Preface Contents Part Developing BASIC Programs on OpenVMS Systems 1 Overview of HP BASIC 1 1 1 2 Language Constructs Supported 0 000 e eee eee Advantages on OpenVMS 0 0 00 c eee eee 2 Developing HP BASIC Programs 2 1 2 1 1 2 1 2 2 1 3 2 1 4 2 2 2 2 1 2 2 2 2 2 3 2 2 4 2 2 5 2 2 6 2 3 2 3 1 2 3 1 1 2 3 1 2 2 3 1 3 Compiling an HP BASIC Program 00000000s BASIC Command 0 0 eee eee tenes BASIC Command Qualifiers 0 0 00 ce eee Declining Qualifiers and Their Recommended Replacements 0 0 0 cee ee eee Compiler Listings 2 2 0 0 cee ees Linking an HP BASIC Program 20 0000 e eee LINK Command ses sa es eisi ede EEE e data a eae 4S LINK Command Qualifiers 0 0 00 0c eee Linker Input Files 0 0 0 00 cece eee Linker Output Files 0 0 0 cee eee Using an Object Module Library Linker Error Messages 000 cc eee eee eens Running an HP BASIC Program 00005 Improving Run Time Performance of HP BASIC Programs 6 4 86 AS 4e SERGE EE RERE REMY RENE SERS ERR E EM Data Nemisis oye vais ae ce ee eee ee eee
127. process different groups of records on different indexed keys or on the same key without incurring all of the RMS overhead of opening the same file more than once For example a program can read records in an indexed file sequentially by one key and randomly by another Each stream is an independent active series of record operations MAP Indmap WORD Emp num amp STRING Emp last name 20 amp SINGLE Salary amp STRING Wage code 2 OPEN IND DAT FOR INPUT AS FILE 13 amp ORGANIZATION INDEXED amp MAP Indmap amp PRIMARY KEY Emp num amp ALTERNATE KEY Emp last_name OPEN IND DAT FOR INPUT AS FILE 2 amp ORGANIZATION INDEXED amp MAP Indmap amp CONNECT 1 13 36 File Input and Output 13 8 4 13 8 5 The channel on which you open the file for the first time is called the parent The CONNECT clause specifies another channel on which you access the same file connected channels are called children More than one OPEN statement can connect to the parent channel however you cannot connect to a channel that has already been connected to another channel Do not use the CONNECT clause when accessing files on remote DECnet nodes CONTIGUOUS Clause A contiguous file with physically adjoining blocks minimizes disk searching and decreases file access time Once the system knows where a contiguous file starts on the disk it does not need to use as many retrieval pointers to locate the pieces of that file Rather
128. program The format is as follows REPORT DEPENDENCY pathname relationship type The pathname parameter identifies the dictionary item that the compiled object module references The path name can specify a CDO format dictionary item with an anchor as the first element or it can specify a CDO format item in the compatibility dictionary which can be specified either as a CDD TOP path name or as an anchor path name See Section 21 2 2 for a full description of the path name options The optional relationship type parameter determines the type of relationship by specifying a CDD Repository protocol There are many valid values refer to the CDD Repository documentation for full information The most commonly used relationship for HP BASIC users is as follows CDD COMPILED DEPENDS ON This specifies a relationship that links a compiled object module to the element that goes into the compilation This is the default The REPORT DEPENDENCY directive is meaningful only when the following conditions are true e The DEPENDENCY_DATA qualifier is specified in the BASIC command line If it is not specified the compiler checks syntax but does not update the dictionary to reflect this usage of the item e The current CDD DEFAULT dictionary points to a directory in a CDO dictionary e The dictionary item specified by pathname is in a CDO format dictionary No relationship can be created in a DMU format dictionary 21 10
129. program to the record buffer A specifies a 1 dimensional string array C specifies a 2 dimensional array of the default data type and D specifies a 3 dimensional integer array B 3 2 specifies the element of array B that appears in row 3 column 2 MOVE TO 5 AS C D amp B 3 2 File Input and Output 13 9 Successive MOVE statements to or from the buffer start at the beginning of the record buffer If a MOVE TO operation only partially fills the buffer the rest of the buffer is unchanged You use the GET statement to read a record from a file and then you move the data from the buffer to variables and reference the variables in your program A MOVE TO operation moves data from the variables into the buffer created by HP BASIC A PUT or UPDATE statement then moves the data from the buffer to the file The following program opens file MOV DAT reads the first record into the buffer and moves the data from the buffer into the variables specified in the MOVE FROM statement DECLARE STRING Emp name Address Department DECLARE LONG Badge OPEN MOV DAT AS FILE 18 amp RELATIVE VARIABLE amp ACCESS MODIFY ALLOW NONE amp RECORDSIZE 512 GET 1 MOVE FROM 18 amp Emp name 25 amp Badge amp Address 25 amp Department 4 MOVE TO 13 amp Emp name 25 amp Badge amp Address 25 amp Department 4 UPDATE 1 CLOSE 1 END The MOVE TO statement moves the data from the named
130. s_floating 3 digits for g floating and t_floating and 4 digits for h_floating and x_ floating In exponential format BASIC does not pad the digits to the left of the decimal point Instead the most significant digit shifts to the leftmost place of the format field and the exponent compensates for this adjustment PRINT USING 5 PRINT USING 1000 PRINT USING 5 END Output 500 00E 02 100 00E 01 50E 01 14 10 Formatting Output with the PRINT USING Statement 14 3 3 6 14 3 3 7 If you use fewer than four carets the number does not print in E format the carets print as literal characters If you use more than four carets BASIC prints the number in E format and includes the extra carets as a string literal PRINT USING 5 PRINT USING 5 END Output 5 00 500 00E 02 You must reserve a place for a minus sign to the left of the decimal point to display negative numbers in exponential format If you do not BASIC prints a percent sign as a warning You cannot use exponential format with asterisk fill floating dollar sign or trailing minus formats Leading Zeros To print leading zeros in a numeric field you must start the format field with a zero enclosed in angle brackets lt 0 gt These characters also reserve one place for a digit DECLARE STRING CONSTANT FM lt O gt PRINT USING FM 1 23 12 34 123 45 1234 56 12345 67
131. same name behave differently depending on whether these statements are in the same program module If they are in the same program module then the storage for each common area is concatenated However if they are in different program units then the common areas overlay the same storage The following COMMON statements are in the same program module therefore they are concatenated in a single PSECT The PSECT contains two 32 byte strings Data Definition 7 11 COMMON XYZ STRING A COMMON XYZ STRING B 32 32 In contrast the following COMMON statements are in different program modules and thus overlay the same storage Therefore the PSECT contains one 32 byte string called A in the main program and B in the subprogram lIn the main program COMMON XYZ STRING A 32 In the subprogram COMMON XYZ STRING B 32 Although you can redefine the storage in a common section when you access it from a subprogram you should generally not do so Common areas should contain exactly the same variables in all program modules To make sure of this you should use the INCLUDE directive as shown in the following example COMMON SHARE WORD emp num amp DECIMAL 8 0 salary amp STRING wage_class 2 lIn the main program SINCLUDE COMMON BAS In the subprogram SINCLUDE COMMON BAS If you use the INCLUDE directive you can lessen the risk of a typographical error For more information about using the INCLUDE directive s
132. single line DEF the function name the formal parameter list and the defining expression all appear on the same line The defining expression specifies the calculations that the function performs You can pass up to 255 arguments to this function through the formal parameter list These parameters are variables local to the function definition and each formal parameter can be preceded by a data type keyword 10 18 Functions The following example creates a function named fnratio This function has two formal parameters numer and denomin whose ratio is returned as a REAL value When the function is invoked HP BASIC does the following e Copies the values 5 6 and 7 8 into the formal parameters numer and denomin e Evaluates the expression to the right of the equal sign e Returns the value to the statement that invoked the function the PRINT statement The PRINT statement then prints the returned value DEF REAL fnratio numer denomin numer denomin PRINT fnratio 5 6 7 8 END Output 717949 Note that the actual parameters you supply must agree in number and data type with those in the formal parameter list you must supply numeric values for numeric variables and string values for string variables The defining expression for a single line function definition can contain any constant variable HP BASIC built in function or any user defined function except the function being defined The following examples are valid f
133. specified a data type after the CDD Repository STRUCTURE keyword HP BASIC translates STRUCTURE to an HP BASIC RECORD or GROUP statement These HP BASIC statements do not allow data type attributes User Action Change the CDD Repository definition CDDATTDIG DIGITS attribute of lt field name gt not supported for datatype Explanation INFORMATION The field contains a CDD Repository fixed point data type that specifies the number of allowed digits This warning tells you that HP BASIC interprets the field as BYTE WORD LONG or QUAD and does not support the DIGITS attribute for this data type User Action None CDDATTSCA CDD Repository specifies SCALE for lt RECORD component gt Not supported Explanation INFORMATION A field in a CDD Repository definition uses the SCALE keyword This warns you that the field has an implied exponent User Action Remove the SCALE attribute in CDD Repository or avoid using the field Compile Time Error Messages A 11 CDDATTTXT CDD Repository TEXT attribute for group lt group name gt ignored Explanation INFORMATION A CDD Repository record definition specifies a data type of TEXT for the entire record User Action None HP BASIC ignores the TEXT attribute and substitutes the UNSPECIFIED attribute CDDBASNAM CDD Repository specified BASIC name lt name gt has illegal form Explanation ERROR The HP BASIC name specified in the CDD Repository record definition is a reserved k
134. specified dimension cannot be returned because the array has fewer dimensions than the one requested User Action Change the dimensions specified with the LBOUND or UBOUND function DIRERR Directive error ERR 253 Explanation A system service call resulted in an error User Action See the VMS I O User s Reference Volume or the OpenVMS Record Management Services Reference Manual DIVBY_ZER Division by 0 ERR 61 Explanation The program attempts to divide a value by zero User Action Check program logic and change the attempted division or trap the error in an error handler DUPKEYDET Duplicate key detected ERR 134 Explanation In a PUT operation to an indexed file a duplicate key was specified and DUPLICATES was not specified when the file was created User Action Change the duplicate key or recreate the file specifying DUPLICATES for that key ECHTYPNOT Prompt echo type not supported ERR 256 Explanation The specified prompt or echo type is invalid HP BASIC supports only the default prompt and echo types User Action Do not change the prompt or echo type If you do so you should continue to use direct calls to Compaq GKS routines rather than use HP BASIC input statements Run Time Messages B 7 ENDFILDEYV End of file on device ERR 11 Explanation The program attempted to read data beyond the end of the file User Action None The program can trap this error in an error handler ENTPOINOT E
135. syntax error MINPAREXP at least lt number gt parameter s expected for lt sub func name gt Explanation ERROR An external SUB or FUNCTION was called with fewer parameters than were specified as non OPTIONAL parameters in the EXTERNAL statement User Action Increase the number of parameters in the call so that the number of parameters is equal to or greater than the number of non OPTIONAL parameters MISENDIF missing END IF directive before end of program unit Explanation ERROR A IF directive crosses a program module boundary User Action Terminate the IF with a WEND IF before beginning a new source module MISENDFOR missing END lt block gt for lt block gt at line lt n gt statement lt m gt Explanation ERROR The program contains a SELECT IF or DEF without a matching END statement User Action Supply a matching END statement MISMATEND mismatched END expected lt block gt Explanation ERROR The program contains an incorrect END statement for example an END RECORD statement instead of an END GROUP statement User Action Supply the correct type of END statement MISMATFOR missing NEXT for lt item gt at line lt n gt statement lt m gt Explanation ERROR The program contains a FOR WHILE or UNTIL without a matching NEXT User Action Supply the matching NEXT statement A 58 Compile Time Error Messages MODNOTEND module lt mod name gt not found in text library lt tex
136. that does not conform to the ANSI Minimal BASIC Standard See Chapter 5 for more information about the ANSI Minimal Standard User Action Although HP BASIC allows you to run programs with non ANSI language features you must remove these features if you want your program to be transportable to other ANSI Minimal BASIC compilers FEANOTAVA language feature not available in Alpha BASIC Explanation Feature is not currently available in Alpha BASIC User Action Rewrite code to work around unavailable feature FIEVALONL FIELD valid only for dynamic string variables Explanation ERROR A FIELD statement contains a numeric or fixed length string variable User Action Remove the numeric or fixed length string variable Only dynamic string variables are valid in FIELD statements FILACCERR file access error for INCLUDE directive lt file name gt Explanation ERROR The file named in the INCLUDE directive was correctly opened but could not be read for some reason for example the disk drive was switched off line User Action Take action based on the associated RMS error messages FILEWRITE lt prog name gt written to file lt file name gt Explanation INFORMATION The specified program name has been saved in file name User Action None FILNOTALL FILL not allowed in MAP DYNAMIC Explanation ERROR A MAP DYNAMIC statement contains a FILL item User Action Remove the FILL item Compile Time Error Messages
137. the LIST qualifier when HP BASIC translates a CDD Repository data definition it does the following e Begins each line of the RECORD statement with the letter C followed by a number The letter C tells you that the RECORD statement is translated from a CDD Repository data definition The number tells you the nesting level of the INCLUDE FROM CDD directive within the source program For example if your source program directly extracts a CDD Repository record definition then each line is preceded by C1 If the CDD Repository extraction came from a file included in the source program then each line of the record definition is preceded by C2 and so on e Includes the explanatory text in the CDDL DESCRIPTION clause as comment fields e Translates the data type text in the subordinate field to a comment field that tells you the data type of each elementary RECORD component For example the comment TEXT tells you that STRING STREET is a text data type 21 6 Using CDD Repository with BASIC HP BASIC requires that a CDD Repository data definition include a minimum of one structure to be translated into a RECORD statement If a CDD Repository data definition contains only a single subordinate field without a structure HP BASIC signals an error because it cannot give a name to the RECORD statement You cannot include a CDO FIELD definition in a HP BASIC program You can however include CDO RECORD definitions that
138. the MOUNT system service to mount tapes 18 1 2 Opening a Tape File for Output To create and open a magnetic tape file for output use the OPEN statement The following statement opens the file PARTS DAT and writes 256 byte records that are blocked four to a physical tape block of 1024 bytes OPEN MT1 PARTS DAT FOR OUTPUT AS FILE 2 SEQUENTIAL FIXED amp RECORDSIZE 256 BLOCKSIZE 4 Specifying FIXED record format creates ANSI F format records Specifying VARIABLE creates ANSI D format records If you do not specify a record format the default is VARIABLE Note Every record in an ANSI D formatted file is prefixed by a 4 byte header giving the record length in decimal ASCII digits The length includes the 4 byte header HP BASIC adds the 4 byte header to the record size when calculating block size The header is transparent to your program If you do not specify a block size HP BASIC defaults to one record per block For small records this can be inefficient the tape will contain many interrecord gaps 18 2 Advanced File Input and Output 18 1 3 18 1 4 Opening a Tape File for Input To open an existing magnetic tape file you also use the OPEN statement For example the following statement opens the file PAYROLL DAT If you do not specify a record size or a block size HP BASIC defaults to the values in the header block If you do not specify a record format HP BASIC defaults to the format present in the h
139. the item to be printed does not match the field The following examples demonstrate invalid character combinations in numeric fields Example 1 PRINT USING S 5 41 16 30 The dollar signs form a complete field and the rest forms a second valid field The first number 5 41 is formatted by the first valid field It prints as 5 The second number 16 30 is formatted by the second field and prints as 16 30 Output 1 5 16 30 Example 2 PRINT USING 5 43E09 Because the field has only three carets instead of four BASIC prints a percent sign and the number followed by three carets Output 2 543E 10 Example 3 PRINT USING LLEEE VWXYZ You cannot combine two letters in one field BASIC interprets EEE as a string literal Output 3 VWXEEE Formatting Output with the PRINT USING Statement 14 17 15 Handling Run Time Errors The process of detecting and correcting errors that occur when your program is running is called error handling This chapter describes default error handling and how to handle HP BASIC run time errors with your own error handlers Throughout this chapter the term error is used to imply any OpenVMS exception not only an exception of ERROR severity 15 1 Default Error Handling HP BASIC provides default run time error handling for all programs If you do not provide your own error handlers the default error handling procedures remain
140. the loop block User Action Make sure that any loop is entirely contained in the THEN or ELSE clause ERLNOTALL ERL statement not allowed in programs without line numbers Explanation ERROR An ERL statement has been found in a program without line numbers User Action Remove the ERL statement Compile Time Error Messages A 27 ERRACCLIB error accessing module lt mod name gt in text library lt text lib name gt Explanation ERROR HP BASIC found an unexpected LIBRARIAN error while trying to INCLUDE a text library module This error message is followed by a specific LIBRARIAN LBR message User Action Take appropriate action based on the associated LBR message ERRCLOLIB error closing text library lt text lib name gt Explanation ERROR The text library specified in a INCLUDE directive could not be closed This error message is followed by the specific LIBRARIAN LBR error User Action Take appropriate action based on the associated LBR message ERROPEFIL error opening file Explanation ERROR The file specified in a INCLUDE directive could not be opened This error message is followed by the specific RMS error User Action Take appropriate action based on the associated RMS error ERROPELIJB error opening text library lt text lib name gt Explanation ERROR The text library specified in a INCLUDE directive could not be opened This error message is followed by the specific LIBRARIAN LBR
141. the old and new values DBG gt SET WATCH TOTAL Subsequently every time the program modifies the value of TOTAL the watchpoint is triggered The debugger monitors watchpoints continuously during program execution The next example shows what happens when your program modifies the contents of a watched variable DBG gt SET WATCH TOTAL DBG gt GO watch of SCREEN IO TOTAL LINE 13 13 TOTAL TOTAL 1 old value 16 new value 17 break at SCREEN IO LINE 14 14 CALL Pop rtn TOTAL DBG gt In this example a watchpoint is set on the variable TOTAL and the GO command starts execution When the value of TOTAL changes execution is suspended The debugger announces the event watch of identifying where TOTAL changed line 13 and the associated source line The debugger then displays the old and new values and announces that execution has been suspended at the start of the next line 14 The debugger reports break 3 10 Using the OpenVMS Debugger with BASIC at but this is not a breakpoint it is still the effect of the watchpoint Finally the debugger prompts for another command When a change in a variable occurs at a point other than the start of a source line the debugger gives the line number plus the byte offset from the start of the line 3 5 Examining and Manipulating Data This section explains how to use the EXAMINE DEPOSIT and EVALUATE commands to display and modify the contents of variables and eva
142. these values when the program runs as opposed to using a constant value For instance the following example assigns sales information to array Sales_data The number of iterations depends on the value of the variable Days_in_month which represents the number of days in that particular month FOR I 1 TO Days _in month Sales data I Quantity sold NEXT I Because the starting ending and step values can be numeric expressions they are not evaluated until the program runs This means that you can have a FOR NEXT loop that does not execute The following example prompts the user for the starting ending and step values for a loop and then tries to execute that loop The loop executes zero times because it is impossible to go from 0 to 5 using a step value of 1 counter 0 INPUT Start start INPUT Finish finish INPUT Step value step val FOR I start TO finish STEP step val counter counter 1 NEXT I PRINT This loop executed counter times Output Start 0 Finish 5 Step value 1 This loop executed 0 times Whenever possible you should use integer variables to control the execution of FOR NEXT loops because some decimal fractions cannot be represented exactly in a binary computer and the calculation of floating point control variables is subject to this inherent imprecision Program Control 9 5 In the following example the first loop uses an integer control variab
143. value and the step value and assigns these results to temporary storage locations 3 Tests whether the ending value has been exceeded If the ending value has already been exceeded HP BASIC executes the statement following the NEXT statement If the ending value has not been exceeded HP BASIC executes the statements in the loop 4 Adds the step value to the control variable and transfers control to the FOR statement which tests whether the ending value has been exceeded Steps 3 and 4 are repeated until the ending value is exceeded Note that HP BASIC performs the test before the loop executes When the control variable exceeds the ending value HP BASIC exits the loop and then subtracts the step value from the control variable This means that after loop execution the value of the control variable is the value last used in the loop not the value that caused loop termination Example 9 1 assigns the values 1 to 10 to consecutive array elements 1 to 10 of New_array and Example 9 2 assigns consecutive multiples of 2 to the odd numbered elements of New_array Example 9 1 Assigning Values to Consecutive Array Elements FOR I 1 TO 10 New_array I I NEXT I 9 4 Program Control Example 9 2 Assigning Consecutive Multiples to Odd Numbered Elements of Array FOR I 1 TO 10 STEP 2 New_array I I 1 NEXT I Note that the starting ending and step values can be run time expressions You can have HP BASIC calculate
144. value to each of the 256 elements of the array DECLARE INTEGER Column number Row number REAL Sales info Two dim array 15 15 FOR Row number 0 TO 15 FOR Column number 0 to 15 INPUT Please enter the sales information Sales info Two dim array Row number Column number Sales info NEXT Column number i 7 NEXT Row_number Note that in nested loops the inner loop is entirely contained in the outer loop nested loops cannot overlap 9 3 Unconditional Branching GOTO Statement The GOTO statement specifies which program line the HP BASIC compiler is to execute next regardless of that line s position in the program If the statement at the target line number or label is nonexecutable such as an REM statement HP BASIC transfers control to the next executable statement following the target line number You can use a GOTO statement to exit from a loop however it is better programming practice to use the EXIT statement 9 8 Program Control 9 4 Conditional Branching Conditional branching is the transfer of program control only when specified conditions are met There are three HP BASIC statements that let you conditionally transfer control to a target statement in your program e ON GOTO OTHERWISE e IF THEN ELSE e SELECT CASE 9 4 1 ON GOTO OTHERWISE Statement The ON GOTO OTHERWISE statement tests the value specified after the ON keyword If the value is 1 HP BASIC transfers contr
145. variable and ret_status is a quoted string expression LET B ret_status The LET statement changes the length of dynamic strings but does not change the length of fixed length strings The following example first creates a fixed length string named ABC by declaring the string in a MAP statement The program then creates a dynamic string named XYZ by declaring it in a DECLARE statement The third line assigns a 3 character value to both variable ABC and XYZ then prints the value and the length of the string String Handling 11 5 11 5 2 variables Variable ABC continues to have a length of 10 the three characters assigned plus seven spaces for padding The length of the dynamic variable changes with the values assigned to it MAP TEST STRING ABC 10 DECLARE STRING XYZ ABC ABC XYZ XYZ PRINT ABC LEN ABC PRINT XYZ LEN XYZ ABC A xyz x PRINT ABC LEN ABC PRINT XYZ LEN XYZ Output ABC 10 XYZ 3 A 10 X 1 LSET Statement The LSET statement left justifies data and assigns it to a string variable without changing the variable s length In the following example ABC is a string variable and ABC is a string constant LSET ABC ABC If the string expression s value is shorter than the string variable s current length LSET left justifies the expression and pads the string variable with spaces In the following example the LET statement creates the 5 character string variab
146. was set make the result negative IF negative THEN mdlo argument ELSE mdlo argument END IF END DEF INPUT PLEASE INPUT THE VALUE AND THE MODULUS X Y PRINT mdlo X Y END Output PLEASE INPUT THE VALUE AND THE MODULUS 7 5 2 Because these functions are declared in DECLARE statements the function names do not have to conform to the traditional HP BASIC rules for naming functions 10 22 Functions Recursion occurs when a function calls itself The following example defines a recursive function that returns a number s factorial value DECLARE INTEGER FUNCTION factor INTEGER DEF INTEGER factor INTEGER F IF F lt 0 THEN factor ELSE factor END IF END DEF INPUT INPUT N TO FIND N FACTORIAL N PRINT N IS factor N END Output INPUT N TO FIND N FACTORIAL 5 N IS 120 1 factor F 1 F Any variable accessed or declared in the DEF function and not in the formal parameter list is global to the program unit When HP BASIC evaluates the user defined function these global variables contain the values last assigned to them in the surrounding program module To prevent confusion variables declared in the formal parameter list should not appear elsewhere in the program Note that if your function definition actually uses global variables these variables cannot appear in the formal parameter list You cannot transfer control into a multiline DEF function except by invoking it You should
147. writes sequential records to the file The following program writes a record to the file Successive PUT operations write successive records OPEN MT0 TEST DAT FOR OUTPUT AS FILE 2 amp SEQUENTIAL FIXED RECORDSIZE 20 BS WHILE BS lt gt NO LINPUT Name AS MOVE TO 2 AS 20 PUT 2 LINPUT Write another record BS NEXT CLOSE 2 END Each PUT writes one record to the file If your OPEN statement specifies a RECORDSIZE clause the record buffer length equals RECORDSIZE or the map size For example RECORDSIZE 60 This clause specifies a record length and a record buffer size of 60 bytes You can specify a record length from 18 to 8192 bytes The default is 132 bytes If you specify a MAP clause and no RECORDSIZE clause then the record size is the size of the map If you also specify BLOCKSIZE the size of the buffer equals the value in BLOCKSIZE multiplied by the record size For example RECORDSIZE 60 BLOCKSIZE 4 These clauses specify a logical record length of 60 bytes and a physical tape record size of 240 bytes 60 4 You specify BLOCKSIZE as an integer number of records RMS rounds the resulting value to the next multiple of four The total I O buffer length cannot exceed 8192 bytes The default is a buffer tape block containing one record To write true variable length records use the COUNT clause with the PUT statement to specify the number of bytes of data written to the file Without COUNT al
148. you do not run out of space when the program is running e Pre extension can make some of the file s disk blocks contiguous especially when used with the CONTIGUOUS keyword Note that pre extension can be a disadvantage if it allocates disk space needed by other users The FILESIZE clause is ignored when HP BASIC opens an existing file 13 38 File Input and Output 13 8 8 13 8 9 NOSPAN Clause By default sequential files allow records to cross or span block boundaries If records cross block boundaries RMS packs records into the file end to end throughout the file leaving space for control information and padding The NOSPAN clause overrides this default forcing records to fit into individual blocks with space provided for control information and padding When block boundaries restrict records fixed length records must be less than 512 bytes and variable length records less than 510 bytes This can waste extra bytes at the end of each block However when records span block boundaries RMS writes records end to end without regard for block boundaries For example if you specify NOSPAN only four 120 byte records fit into a disk block If you do not specify NOSPAN BASIC begins writing the fifth record in the block and continues writing that record in the next block This minimizes wasted disk space and improves the file s capacity at the minimal expense of increased processing overhead RECORDTYPE Clause The RECORD
149. you to access the field name within the group An example of how HP BASIC translates unsupported CDD Repository data types is shown in the following CDDL data definition and corresponding HP BASIC RECORD statement CDDL Definition define record CDDS top basic stock description is this is an example data definition that contains data types not supported by HP BASIC stock structure product no datatype is text size is 8 characters date_ordered datatype is date status code datatype is unsigned byte quantity datatype is unsigned longword aligned on longword location array 1 4 datatype is text size is 30 characters unit price datatype is longword end stock structure end stock Using CDD Repository with BASIC 21 17 Translated RECORD Statement 1 SINCLUDE FROM CDD CDDSTOP BASIC STOCK cl This is an example data definition that contains Cl data types not supported by HP BASIC cl RECORD STOCK UNSPECIFIED cl STRING PRODUCT NO 8 TEXT cl GROUP DATE ORDERED DATE Cl STRING STRING VALUE 8 Cl END GROUP Cl GROUP STATUS CODE UNSIGNED BYTE cl BYTE BYTE VALUE Cl END GROUP cl STRING FILL 3 cl GROUP QUANTITY UNSIGNED LONGWORD Cl LONG LONG VALUE Cl END GROUP cl STRING LOCATION 1 TO 4 30 TEXT cl GROUP UNIT PRICE UNSIGNED LONGWORD C1 LONG LONG VALUE Cl END GROUP cl END RECORD BASIC I CDDSUBGRO data type in CDD Repository not supported substituted group for STOCK DATE ORDERED
150. 00 10 Subprogram SUB SUB1 COMMON ABC STRING new list 1 TO 100 10 6 6 Arrays 6 2 4 Creating Arrays with the MAP Statement Create arrays with the MAP statement only when you want the array to be part of a record buffer or when you want to overlay the storage containing the array Note that string arrays in maps are always fixed length You associate the array with a record buffer by naming the map in the MAP clause of the OPEN statement In the following example the MAP statement creates two arrays an 11 element fixed length string array named team and a 33 element array of WORD integers named bowling_scores Because the OPEN statement specifies MAP ABC the storage for these arrays is used as the record buffer for the open file MAP ABC STRING team 10 20 WORD bowling scores 0 TO 32 OPEN BOWLING DAT AS FILE 1 SEQUENTIAL VARIABLE MAP ABC 6 3 Creating Arrays Implicitly Create arrays implicitly as follows e By referencing an element of an array that has not been explicitly declared e By using MAT statements When you first create an implicit array the lower bound is zero and the upper bound is 10 An array created by referencing an element can have up to 32 dimensions in BASIC An array created with a MAT statement can have only one or two dimensions Note The ability to create arrays implicitly exists for compatibility with previous implementations of BASIC However it is better programming pra
151. 132 User Action Either decrease the amount of data entered at one time or increase the size of the input buffer You can explicitly OPEN the input device and specify the input buffer size with the RECORDSIZE or MAP clause MATDIMERR Matrix dimension error ERR 124 Explanation The program attempts to e Assign more than two dimensions to an array e Reference an array with fewer or more subscripts than there are dimensions in the array e Redimension an array that cannot be redimensioned e Perform a matrix operation with an array that has a lower bound other than zero in any of its dimensions Run Time Messages B 19 This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Change the number of array subscripts Reference the array using the correct number of dimensions change the array so that it can be redimensioned or change the array so that its lower bounds are zero in all of its dimensions MAXMEMEXC Maximum memory exceeded ERR 126 Explanation The program has insufficient string and I O buffer space because 1 its allowable memory size has been exceeded or 2 the system s maximum memory capacity has been reached This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Reduce the amount of string or I O buffer space or split the program into two or more programs MEMMANV
152. 14 3 2 14 3 3 14 3 3 1 14 3 3 2 14 3 3 3 14 3 3 4 14 3 3 5 14 3 3 6 14 3 3 7 14 3 3 8 14 4 14 4 1 14 4 2 14 4 3 14 4 4 Printing Numbers Specifying the Number of Digits 0 000 Specifying Decimal Point Location 005 Printing Numbers with Special Symbols Commas Asterisk Fill Fields cerca eo G28 ae oe ee ae ike WEE eS Currency Symbols 0 0 00 cece eee eee Negative Fields 0 0 0 ccc cece eens E Exponential Format 0 0000 Leading Zeros 0 ce eens Blank If Zero Fields 1 0 0 0 0c cece eee Debits and Credits 0 0 0 0 cece eee Printing Strings Left Justified Format 0 0 000000 cece ee eee Right Justified Format 0 0 0 cece eee Centered Fields Extended Fields 13 30 13 30 13 31 13 31 13 31 13 32 13 33 13 33 13 34 13 34 13 36 13 36 13 37 13 37 13 38 13 38 13 39 13 39 13 40 13 40 13 43 14 1 14 2 14 3 14 4 14 5 14 6 14 7 14 8 14 9 14 9 14 10 14 11 14 11 14 12 14 12 14 14 14 14 14 15 14 15 14 5 PRINT USING Statement Error Conditions 15 Handling Run Time Errors 15 1 Default Error Handling 15 2 User Supplied Error Handlers 15 2 1 Protected Regions 00 eee e eee 15 2 2 Handlers serete dronit oo Oe ae de pee Rii 15 2 3 Exiting from Handlers 15 2 3 1 RETRY Statem
153. 2 When you write records HP BASIC does not prefix the records with any count bytes Reading Records from a Disk File You read data by defining a record buffer and reading the data from the device with GET statements After the data has been retrieved with a GET statement you can deblock the data with MOVE or REMAP statements In the following example each disk block contains twelve 40 byte records Each record contains a 32 byte string a 4 byte SINGLE number and a 4 byte LONG integer After each GET operation the FOR NEXT loop uses the REMAP statement to redefine the position of the variables in the record At the end of the file the program closes the file See Chapter 7 and the HP BASIC for OpenVMS Reference Manual for more information about the MAP MAP DYNAMIC and REMAP statements 18 12 Advanced File Input and Output MAP SAM FILL 512 MAP DYNAMIC SAM STRING PRT ID SINGLE MAFLD LONG ADIR OLDN OPEN DUA1 FOR INPUT AS FILE 2 SEQUENTIAL FIXED amp ACCESS READ MAP SAM WHEN ERROR USE err hand WHILE 13 1 E GET 2 FOR I 0 TO 11 REMAP SAM STRING FILL I 40 PRT ID 32 MAFLD ADIR OLDN PRINT PRT ID MAFLD ADIR OLDN NEXT I NEXT END WHEN HANDLER err hand IF ERR lt gt 113 THEN EXIT HANDLER END IF END HANDLER CLOSE 2 END 18 3 I O to Mailboxes A mailbox is a record I O device that passes data from one process to another You can use a valid mailbox name as a file name and trea
154. 2 1 12 1 1 Subprograms can return a value to the calling program with parameters You can use subprograms to separate routines that you commonly use For example you can use subprograms to perform file I O operations to sort data or for table lookups You can also use subprograms to separate large programs into smaller more manageable routines or you can separate modules that are modified often If all references to system specific features are isolated it is easier to transport the program to a different system OpenVMS System Services and OpenVMS Run Time Library routines are specific to OpenVMS systems therefore you should consider isolating references to them in subprograms Chapter 19 describes how to access Run Time Library routines and system services from HP BASIC You should also consider isolating complex processing algorithms that are used commonly If complex processing routines are isolated they can be shared by many programs while the complexity remains hidden from the main program logic However they can share data only if the following is true e Data is passed as a parameter from the CALL statement or function invocation to the subprogram see Section 12 2 for more information e Data is part of a MAP or COMMON block see Chapter 6 for information about using MAP and COMMON statements e Data is in a file see Chapter 13 for more information about accessing data from a file All DATA statements are local to
155. 2 5 e Specify an options file An options file can contain additional file specifications for the LINK command as well as special linker options You must use the OPTIONS qualifier to specify an options file For more information about options files see the HP OpenVMS Linker Utility Manual The linker uses the following default file types for input files File File Type Object module OBS Object library OLB Options file OPT 2 2 4 Linker Output Files When you enter the LINK command interactively and do not specify any qualifiers the linker creates only an executable image file By default the resulting image file has the same file name as the first object module specified and the file type EXE In a batch job the linker creates both an executable image file and a storage map file by default The default file type for map files is MAP To specify an alternative name for a map file or image file or to specify an alternative output directory or device you can include a file specification on the MAP or EXECUTABLE qualifier For example LINK UPDATE MAP TEST Developing HP BASIC Programs 2 25 2 2 5 Using an Object Module Library In a large development effort the object modules for subprograms are often stored in an object module library By using an object module library you can make program modules contained in the library available to other programmers To link modules contained in an object module libra
156. 23 12345 678 If there are not enough digits to fill the field HP BASIC prints spaces before the first digit format string PRINT USING format string 1 PRINT USING format string 10 PRINT USING format string 1709 PRINT USING format _string 12345 END Output 1 10 1709 12345 If you have not reserved enough digits to print the fractional part of a number HP BASIC rounds the number to fit the field PRINT USING 126 7 PRINT USING 5 9 PRINT USING 5 4 END 14 4 Formatting Output with the PRINT USING Statement 14 3 2 Output 127 6 5 If you have not reserved enough places to print a number s integer portion HP BASIC prints a percent sign as a warning followed by the number in PRINT statement format After HP BASIC prints the number it completes the rest of the list in PRINT USING format In the following example PRINT USING displays the first number Because there are not enough places to the left of the decimal point to display a 3 digit number BASIC prints the second number in PRINT statement format with a space before and after but includes a percent sign warning PRINT USING 256 PRINT USING 256 END Output 256 256 Specifying Decimal Point Location The decimal point s position in the format string determines the number of reserved places on either side of it If the print item s fractional part does not use all of the reserved places to the right
157. 3 27 Record formats 13 1 to 13 2 RECORD instances 8 1 arrays of 8 3 Record operations 13 11 Records blocking and deblocking of 18 6 writing to a terminal format file 5 14 writing with PUT and GET statements 18 3 RECORD statement 8 1 to 8 13 RECORD templates 8 1 RECORD variants 8 5 to 8 8 RECOUNT function 13 33 REGARDLESS clause 13 18 18 25 Relationship dictionary 21 4 Relationship type 21 10 Relative files 13 3 REMAP statement 7 13 Remote files accessing 18 15 REPORT directive 21 10 RESTORE statement 5 7 rewinding tape with 18 6 with magnetic tapes 18 10 RESUME statement 15 7 15 22 to 15 23 to a label 15 22 to a line number 15 22 Retrieval pointers 13 43 RETRY statement 15 8 RFA data type 4 7 Right justification RSET statement 11 7 Right justified format with PRINT USING statement 14 14 RMSSTATUS function 13 33 to 13 34 15 16 RND function 10 5 ROUND_DECIMAL qualifier 2 14 RSET statement concatenating strings 11 2 with dynamic strings 11 2 with string data 11 7 RUN command 2 28 Run time errors 15 1 to 15 23 Run Time Library routines 19 11 S SBTTL directive 16 3 SCALE qualifier 2 15 Screen mode 3 2 SEG function string function 11 12 SELECT CASE statement 9 12 to 9 14 with RECORD variants 8 6 Semicolons using with PRINT statement 5 10 SEPARATE_COMPILATION 2 15 Sequential files 13 3 SET BREAK debugger command 3 7 SET MODE SCREEN debug
158. 4 RND 4 NEXT I END Output 52616 35996 80576 77968 77402 95189 76439 37156 2776 53843 AU er a one BUO Data Conversion Functions HP BASIC provides built in functions that can perform the following e Convert a 1 character string to the character s ASCII value and vice versa e Translate strings from one data format to another for example EBCDIC to ASCII The following sections describe some of these functions ASCII Function The ASCII function returns the numeric ASCII value of a string s first character The ASCII function returns an integer value from 0 to 255 inclusive For instance in the following example the PRINT statement prints the integer value 66 because this is the ASCII value equivalent of an uppercase B the first character in the string 10 6 Functions 10 1 2 2 10 1 3 test_string BAT PRINT ASCII test_string END Output 66 Note that the ASCII value of a null string is zero CHR Function The CHR function returns the character whose ASCII value you supply If the ASCII integer expression that you supply is less than zero or greater than 255 HP BASIC treats it as a modulo 256 value HP BASIC treats the integer expression as the remainder of the actual supplied integer divided by 256 Therefore CHR 325 is equivalent to CHR 69 and CHR 1 is equivalent to CHR 255 The following program outputs the character whose ASCII value corresponds to the input value mod
159. 4321 FOR Ib 5 TO 5 PRINT PLACE number I NEXT I PRINT FOR I 9995 TO 10005 PRINT PLACE number I3 NEXT I 10 12 Functions 10 1 5 Output 12 123 1235 12346 123457 123456 7 123456 65 123456 654 123456 6543 123456 65432 12 123 1234 12345 123456 123456 6 123456 65 123456 654 123456 6543 123456 65432 The PROD function returns the product of two numeric strings The returned string s precision depends on the value you specify for the integer precision expression AS 4 333 BS 7 23326 s_product PROD A BS 100058 PRINT s product END T Output 31 34171 Date and Time Functions HP BASIC supplies functions to return the date and time in numeric or string format The following sections discuss these functions Note that you can also use certain system services and Run Time Library routines for more sophisticated date and time functions See the HP OpenVMS System Services Reference Manual and the VMS Run Time Library Routines Volume for more information Functions 10 13 10 1 5 1 10 1 5 2 10 1 5 3 DATE Function The DATE function returns a string containing a day month and year in the form dd Mmm yy The date integer argument to the DATE function can have up to six digits in the form yyyddd where yyy specifies the number of years since 1970 and ddd specifies the day of that year If the numeric expression is zero DATE returns the current date PRINT
160. 6 input files 2 25 output files 2 25 Linking DEBUG 3 1 LINPUT statement 5 3 to 5 4 5 13 disabling the prompt 5 4 to 5 5 with strings 11 3 List 6 1 LIST directive 16 5 Listing compilation 2 21 LISTING qualifier 2 10 2 21 LOC function 19 8 LOG10 function 10 4 Logarithms common 10 4 Logical names defining 13 13 example of 13 13 using 13 13 LONG data type 4 7 subtypes 4 7 Loop blocks 9 3 Loop control variable 9 3 Loop index 9 3 Loops 9 3 to 9 8 FOR NEXT 9 3 to 9 6 UNTIL NEXT 9 7 WHILE NEXT 9 6 to 9 7 Lower bounds with COMMON statement 7 5 with MAP statement 7 6 with the RECORD statement 8 4 LSE C 1 to C 4 LSET statement concatenating strings 11 2 with dynamic strings 11 2 with string data 11 6 M MACHINE_CODE qualifier 2 10 Magnetic tape block sizes 18 5 Magnetic tape files creating 18 2 creating for output 18 8 existing 18 3 opening 18 2 18 8 Mailboxes creating 18 13 passing data between processes 18 13 Map area defining 7 11 MAP DYNAMIC statement 7 13 Index 9 Maps multiple 7 8 single 7 6 MAP statement 6 7 7 6 overlaying array storage with 6 7 with subprograms 7 11 MAT INPUT statement 6 14 continuing input line with ampersand 6 16 filling array elements with 6 15 from a terminal 6 14 from a terminal format file 6 14 prompt character 6 15 subscripts in 6 14 MAT LINPUT statement 6 16 filling array eleme
161. 6 1 When used with the LET statement HP BASIC string functions let you manipulate and modify strings These functions let you e Determine the length of a string LEN e Search for the position of a set of characters in a string POS e Extract segments from a string SEG MID e Create a string of any length made up of any single character STRING e Create a string of spaces SPACE e Remove trailing spaces and tabs from a string TRM e Edit a string EDIT These functions are discussed in the following sections See the HP BASIC for OpenVMS Reference Manual for more information about each string s function LEN Function The LEN function returns the number of characters in a string as an integer value For example LEN spec String Handling 11 9 Spec is a string expression The length of the string expression includes leading and trailing blanks In the following example the variable Z is set equal to ABC XYZ which has a length of eight alpha ABCDEFGHIJKLMNOPQRSTUVWXYZ PRINT LEN alpha Z ABC xyzZ PRINT LEN ZS END Output 26 8 11 6 2 POS Function The POS function searches a string for a group of characters a substring In the following example spec is the string to be searched test is the substring for which you are searching and 15 is the character position where HP BASIC starts the search POS spec test 15 The position returned by POS is relative to the beg
162. 6 Deleting Files If the security constraints permit you can delete a file with the KILL statement For example KILL TEST DAT This statement deletes the file named TEST DAT Note that this statement deletes only the most current version of the file Do not omit the file type because there is no default You can delete only one file at a time to delete all versions of a file matching a file specification use the Run Time Library routine LIB DELETE_FILE You can delete a file that is currently being accessed by other users however the file is not deleted until all users have closed it You cannot open or access a file once you have deleted it 13 7 File Related Functions The following built in functions are provided for finding e The characteristics of the last file opened FSP e The number of bytes moved in the last I O operation RECOUNT e The file status STATUS VMSSTATUS and RMSSTATUS File Input and Output 13 31 These functions are discussed in the following sections 13 7 1 FSP Function If you do not know the organization of a file you can find out by opening the file for input with the ORGANIZATION UNDEFINED and RECORDTYPE ANY clauses Your program can then use the FSP function to determine the characteristics of that file Your program must execute FSP immediately after the OPEN FOR INPUT statement For example RECORD FSP data VARIANT CASE BYTE Org BYTE Rat WORD Max record size LONG File size WORD B
163. 7 6 8 6 9 6 9 6 10 6 10 6 12 6 14 6 14 6 6 4 6 6 5 6 6 6 6 7 6 7 1 6 7 1 1 6 7 1 2 6 7 1 3 6 7 2 6 7 2 1 6 7 2 2 6 7 2 3 MAT LINPUT Statement MAT PRINT Statement Matrix I O Functions NUM and NUM2 Matrix Operators Arithmetic Matrix Operations Assignment Addition and Subtraction Multiplication Matrix Functions TRN Function INV Function DET Function 7 Data Definition 7 1 7 2 7 3 7 4 7 5 7 6 7 7 7 7 1 7 7 2 T2 7 7 2 2 7 7 3 7 7 4 45 Declarative Statements Data Types 2 005 Setting the Default Data Type and Size 05 Declaring Variables Declaring Named Constants Operations with Multiple Data Types Allocating Dynamic and Static Storage 000 COMMON Statement MAP Statement Single Maps Multiple Maps FILL Items Using COMMON and MAP Statements in Subprograms Dynamic Mapping 8 Creating and Using Data Structures vi 8 1 8 1 1 8 1 2 8 1 3 RECORD Statement Grouping RECORD Components RECORD Variants Accessing RECORD Components 7 1 9 Program Control 10 9 1 9 1 1 9 1 2 9 1 3 9 1 4 9 1 5 9 1 6 9 2 9 2 1 9 2 2 9 2 3 9 7 1 9 7 2 9 7 3 9 7 4 Functi
164. 82 character line has additional print zones starting at columns 71 85 99 and 113 The PRINT statement formats program output into these zones in different ways depending on the character that separates the elements to be printed If a comma precedes the PRINT item BASIC prints the item at the beginning of the next print zone If the last print zone on a line is filled BASIC continues output at the first print zone on the next line For example INPUT A B C D E F PRINT A B C D E F END Output 5 10 15 20 25 30 Return 5 10 15 20 25 30 BASIC skips one print zone for each extra comma between list elements For example the following program prints the value of A in the first zone and the value of B in the third zone A 5 B 10 PRINT first zone third zone PRINT A B END Simple Input and Output 5 9 Output first zone third zone 5 10 If you separate print elements with a semicolon BASIC does not move to the next print zone In the following example the first PRINT statement prints two numbers Printed numbers are preceded by a space or a minus sign and followed by one space The second PRINT statement prints two strings PRINT 10 20 PRINT ABC XYZ END Output 10 20 ABCXYZ Whether you use a comma or a semicolon at the end of the PRINT statement the cursor remains at its current position until BASIC encounters another PRINT or INPUT statement In the following example BASIC prints
165. AD data items instead of BYTE and WORD accessing LONG or QUAD items is faster than BYTE and WORD which may require multiple hardware instructions On Alpha use GFLOAT or TFLOAT data items instead of DOUBLE operations are faster on GFLOAT and TFLOAT items Operations on DOUBLE operands are performed by converting to GFLOAT performing the operation in GFLOAT and converting back to DOUBLE On Itanium use IEEE data items instead of VAX floating point data items VAX data type operands are converted to appropriate IEEE types before being operated on Choose packed decimal lengths that are the most efficient while still meeting the needs of the application The most efficient sizes are the default size of 15 digits which fits exactly in a quadword and 7 digits which fits exactly in a longword If you use one of these preferred sizes it should be aligned on a quadword or longword boundary Use packed decimal only when it is the appropriate data type For example do not use packed decimal to specify array subscripts which are integers Minimize mixed data type expressions especially when you use packed decimal 2 3 1 2 Qualifiers On your BASIC command line consider the following when you specify qualifiers Use overflow and bounds checking only if they are needed See Section 2 1 2 bounds checking is needed if your program is not thoroughly debugged Both of these CHECK options are on by default and will hinder performanc
166. AN Functions The SIN COS and TAN functions return the sine cosine and tangents of an angle in radians or degrees depending on which angle clause you choose with the OPTION statement If you supply a floating point argument to the SIN COS and TAN functions they return a number of the same floating point type If you supply an integer argument they convert the argument to the default floating point data type and return a floating point number of that type The following example accepts an angle in degrees converts the angle to radians and prints the angle s sine cosine and tangent CONVERT ANGLE X TO RADIANS AND FIND SIN COS AND TAN PRINT DEGREES RADIANS SINE COSINE TANGENT FOR I 0 TO 5 READ X LET Y X 2 PI 360 PRINT PRINT X Y SIN Y COS Y TAN Y NEXT I DATA 0 10 20 30 360 45 END Output DEGREES RADIANS SINE COSINE TANGENT 0 0 0 1 0 10 174533 173648 984808 176327 20 349066 34202 939693 36397 30 523599 lt 5 866025 257795 360 6 28319 174846E 06 1 174846E 06 45 785398 707107 707107 1 Note As an angle approaches 90 degrees PI 2 radians 270 degrees 3 PI 2 radians 450 degrees 5 PI 2 radians and so on the tangent of that angle approaches infinity If your program tries to find the tangent of such an angle HP BASIC signals Division by 0 ERR 61 Functions 10 3 10 1 1 4 10 1 1 5 SQR Function The SQR function returns the square root of a number F
167. AP to be associated with nonexistent storage User Action Change the REMAP statement so that all variables are associated with the storage in the MAP REMSTRNOT REMAP string is not static ERR 196 Explanation The program referenced a string with a REMAP statement that was not declared in COMMON or MAP User Action Declare the string in the COMMON or MAP statement Run Time Messages B 25 RESNO_ERR RESUME and no error ERR 104 Explanation The program executes a RESUME statement without a line number outside of the error handling routine This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Check program logic to make sure that the RESUME statement is executed only in the error handler RETWITGOS RETURN without GOSUB ERR 72 Explanation The program executes a RETURN statement before a GOSUB This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Check program logic to make sure that RETURN statements are executed only in subroutines or remove the RETURN statement RRVNOTFUL RRV not fully updated HRR 171 Explanation RMS wrote a record successfully but did not update one or more Record Retrieval Vectors therefore you cannot retrieve any records associated with those vectors User Action Delete the record and rewrite it SCAFACINT SCALE factor interlock ERR 127 Ex
168. BASIC I CDDSUBGRO data type in CDD Repository not supported substituted group for STOCK STATUS CODE BASIC I CDDSUBGRO data type in CDD Repository not supported substituted group for STOCK QUANTITY BASIC I CDDSUBGRO data type in CDD Repository not supported substituted group for STOCK UNIT PRICE Table 21 2 describes CDD Repository data types not supported by HP BASIC and their translation Table 21 2 Unsupported CDD Repository Data Types Data Type HP BASIC Translation UNSIGNED BYTE UNSIGNED WORD 21 18 Using CDD Repository with BASIC GROUP CDD Repository field name BYTE BYTE_VALUE END GROUP GROUP CDD Repository field name WORD WORD_VALUE END GROUP continued on next page Table 21 2 Cont Unsupported CDD Repository Data Types Data Type HP BASIC Translation UNSIGNED LONGWORD SIGNED QUADWORD UNSIGNED QUADWORD SIGNED OCTAWORD UNSIGNED OCTAWORD H_FLOATING F_FLOATING COMPLEX D_FLOATING COMPLEX G_FLOATING COMPLEX H_FLOATING COMPLEX ZONED NUMERIC GROUP CDD Repository field name LONG LONG_VALUE END GROUP GROUP CDD Repository field name STRING STRING_VALUE 8 END GROUP GROUPCDD Repository field name STRING STRING_VALUE 8 END GROUP GROUP CDD Repository field name STRING STRING_VALUE 16 END GROUP GROUP CDD Repository field name STRING STRING_VALUE 16 END GROUP GROUP CDD Repository field name STRING STRING_VALUE 16 END GROUP GROUP CDD
169. BJ by separating the file names with commas BASIC main subl sub2 To link these programs you must specify all object files as input to the OpenVMS Linker Alternatively you can compile multiple modules into a single object file at the DCL command level by separating the file names with a plus sign as follows BASIC maintsubl sub2 The plus signs used to separate the file names instruct HP BASIC to create a single object file called MAIN OBJ from the three source modules To link this program you specify only one input file to the linker When creating a multiple unit program follow these rules e Ifthe source file contains line numbers then the line numbers for each subprogram must be numerically greater than the highest line number of all preceding subprograms e Line numbers must be unique and no greater than 32767 e Each subprogram must end with an END SUB or END FUNCTION statement before the next subprogram begins e Ifthe source file contains line numbers then text following an END SUB or END FUNCTION statement must begin on a numbered line e Ifthe source file does not contain line numbers then text following an END SUB or END FUNCTION statement must begin on a new physical line Note that in a multiple unit program that contains line numbers any comments or statements following an END END SUB or END FUNCTION statement become part of the preceding subprogram unless they begin on a numbered line In a m
170. Both the VMSSTATUS and RMSSTATUS functions are used to determine which non BASIC error caused a resulting BASIC error In particular VMSSTATUS can be used for any non BASIC errors while RMSSTATUS is used specifically for RMS errors For more information about these functions see Chapter 15 and the HP BASIC for OpenVMS Reference Manual 13 8 OPEN Statement Options This section explains the OPEN statement keywords that enable you to control how a file is created or opened These keywords are BUCKETSIZE BUFFER CONNECT CONTIGUOUS DEFAULTNAME EXTENDSIZE FILESIZE NOSPAN RECORDTYPE TEMPORARY USEROPEN WINDOWSIZE 13 8 1 BUCKETSIZE Clause The BUCKETSIZE clause applies only to relative and indexed files A bucket is a logical storage structure that RMS uses to build and maintain relative and indexed files on disk devices A bucket consists of one or more disk blocks The default bucket size is the record size rounded up to a block boundary Although RMS defines the bucket size in terms of disk blocks the BUCKETSIZE clause specifies the number of records a bucket contains For example OPEN STOCK_DATA DAT FOR OUTPUT AS FILE 18 amp ORGANIZATION RELATIVE FIXED BUCKETSIZE 12 This example specifies a bucket containing approximately 12 records RMS reads in entire buckets into the I O buffer at once and a GET statement transfers one record from the I O buffer to your program s record buffer When you open an existing relative or
171. C or REMAP Explanation ERROR You cannot use a static string that is a parameter declared in a DEF or DEF function as the storage area in a MAP DYNAMIC or REMAP statement User Action Change the storage area specification in the MAP DYNAMIC or REMAP statement to use either a MAP name or a static string variable that is not a parameter to the DEF or DEF function A 22 Compile Time Error Messages DELETE ignoring lt item gt Explanation ERROR The program contains a syntax error The compiler tries to recover from the error by ignoring an operator or separator in the source line For example DIM A 3 is a syntax error but HP BASIC continues the compilation by ignoring the comma The compilation continues only in order to discover other errors no object module is produced User Action Correct the syntax error in the displayed line DEPNOTANS DEPENDENCY_DATA qualifier not allowed with ANSI Explanation ERROR The DEPENDENCY_DATA qualifier conflicts with the ANSI_STANDARD qualifier User Action Specify either the DEPENDENCY_DATA qualifier or the ANSISTANDARD qualifier but not both DESCOMABORT DESIGN COMMENT processing has been aborted due to an internal error please submit an SPR Explanation INFORMATION The compiler was unable to process comment information due to an internal error User Action Please submit a software problem report SPR with the source code of a small program that produces the err
172. COUNT is reset by every read operation on any channel including the controlling terminal Therefore if you need to use the value of RECOUNT copy it to another variable before executing another read operation RECOUNT is undefined if an error occurs during a read operation RECOUNT is often used as the argument to the COUNT clause in the UPDATE or PUT statement for variable length files The following sequence of statements ensures that the output record on channel 5 is the same length as the input record on channel 4 GET 4 bytes readt RECOUNT PUT 5 COUNT bytes read STATUS VMSSTATUS and RMSSTATUS Functions The STATUS function accesses the status longword that contains characteristics of the last opened file If an error occurs during an input operation the value of STATUS is undefined If an error does not occur the six low order bits of the returned value contain information about the type of device accessed by the last input operation These bits correspond to the following devices e If bit 0 is set the device type is a record oriented device e If bit 1 is set the device type is a carriage control device e If bit 2 is set the device type is a terminal e If bit 3 is set the device type is a directory oriented device e If bit 4 is set the device type is a single directory device e If bit 5 is set the device type is a sequential block oriented device magnetic tape or TK50 File Input and Output 13 33
173. Calling Standard 19 8 OpenVMS data structures table of 19 12 OpenVMS Debugger 3 1 to 3 18 See Debugger OpenVMS symbolic debugger See Debugger Operand 4 13 Operator 4 13 Optimization with handlers 15 9 OPTIMIZE qualifier 2 12 OPTION HANDLE statement 15 11 Output 5 8 to 5 13 displaying with PRINT statement 5 8 format for numbers 5 12 format for strings 5 12 to 5 13 to terminal format files 5 13 to 5 15 P Packed decimal data type 4 7 format 17 8 string descriptors 17 11 variables 4 11 PAGE directive 16 4 Parameter passing mechanisms 19 1 to 19 4 declaring in EXTERNAL statement 12 4 default 19 38 Parameters creating local copies of 19 4 to 19 5 default data types for 12 6 null 19 7 passing BY DESC 19 2 passing BY REF 19 2 Index 11 Parameters cont d passing BY VALUE 19 2 Path name 21 10 PC and SHOW CALLS debugger display 3 6 and source display 3 3 and STEP debugger command 3 5 breakpoint 3 8 PICTURE subprograms 12 1 PLACE function 10 12 precision of 10 11 significant digits 10 10 Placeholders reserving with PRINT USING statement 14 4 POS function string function 11 10 Positional qualifiers rules for precedence 2 2 Predefined constants BEL 4 9 BS 4 9 CR 4 9 DEL 4 9 ESC 4 9 FF 4 9 HT 4 9 LF 49 PI 4 9 SI 49 SO 4 9 SP 4 9 VT 49 PRINT directive 16 10 PRINT statement 5 8 5 13 expression values 5 8
174. Compile Time Errors HP BASIC diagnoses compile time errors and does the following Indicates the program line that generated the error or errors Displays this program line Shows you the location of the error or errors and assigns a number to each location for future reference Displays the mnemonic statement number within the line the location number as previously displayed and the message text This is repeated for each error in the line HP BASIC repeats this procedure for each error diagnosed during compilation The error message format for compile time errors is BASIC lt I gt lt mnemonic gt lt n gt lt message gt lt l gt Is a letter indicating the severity of the error The severity indicator can be one of the following I indicating information W indicating a warning E indicating an error F indicating a severe error lt mnemonic gt Is a 3 to 9 character string that identifies the error Error messages in this appendix are alphabetized by this mnemonic Compile Time Error Messages A 1 lt n gt Is the nth error within the line s picture lt message gt Is the text of the error message For example Diagnostic on source line 1 listing line 1 BASIC line 10 10 DECLARE REAL BYTE A A sssssesosoosososoesocooo Tiaisa s2 BASIC E CONDATSPC 1 conflicting data type specifications BASIC E ILLMULDEF 2 illegal multiple definition of name A This display tells you
175. Constants can be of the following types e Integer e Floating point e Packed decimal 4 8 BASIC Concepts and Elements e String In addition predefined constants are provided and are useful for the following e Formatting program output to improve clarity e Making source code easier to understand e Using nonprinting characters without having to look up their ASCII values Table 4 1 lists the predefined constants Table 4 1 Predefined Constants Decimal ASCII Constant Value Description BEL Bell 7 Sounds the terminal bell BS Backspace 8 Moves cursor one position to the left HT Horizontal Tab 9 Moves cursor to the next horizontal tab stop LF Line Feed 10 Moves cursor to the next line VT Vertical Tab 11 Moves cursor to the next vertical tab stop FF Form Feed 12 Moves cursor to the start of the next page CR Carriage Return 13 Moves cursor to the beginning of the current line SO Shift Out 14 Shifts out for communications networking screen formatting and alternate graphics SI Shift In 15 Shifts in for communications networking screen formatting and alternate graphics ESC Escape 27 Marks the beginning of an escape sequence SP Space 32 Inserts one blank space in program output DEL Delete 127 Deletes the last character entered PI None Represents the number PI with the precision of the default floating point data type These predefined constants simplify the task of using nonprinting characters in
176. D Repository uses a dictionary structure known as CDO format The type of dictionary used in CDD versions prior to Version 4 0 is known as DMU format You can have many CDO format dictionaries on an OpenVMS system but only one DMU format dictionary The two types of dictionaries can coexist on a system and a program can refer to data definitions in both types 21 2 CDD Repository Concepts This section introduces CDD Repository concepts Using CDD Repository with BASIC 21 1 21 2 1 21 2 2 Dictionary Formats CDD Repository allows the following types of dictionaries e DMU format dictionary e CDO format dictionary These dictionaries can coexist on a system to form one logical directory structure CDD Repository uses a special dictionary known as the compatibility dictionary that allows an application to refer to dictionary definitions without concern about which type of dictionary format the definitions are stored in The compatibility dictionary is a CDO format dictionary whose directory hierarchy matches that of the DMU format dictionary if any on the system Note The compatibility dictionary is an installation option for CDD Repository If there is no compatibility dictionary an application program can refer to both types of dictionaries In this case refer to the CDO format dictionary with an anchor origin path name and to the DMU format dictionary with a CDD TOP path name Anchor origin path names are descri
177. Debugger see the HP OpenVMS Debugger Manual Online help is available during debugging sessions 3 1 Overview of the Debugger A debugger is a tool to help you locate run time errors quickly It is used with a program that has already been compiled and linked successfully with no errors reported but that does not run correctly For example the output might be obviously wrong the program goes into an infinite loop or the program terminates prematurely The debugger enables you to observe and manipulate the program s execution interactively step by step until you locate the point at which the program stopped working correctly The OpenVMS Debugger is a symbolic debugger which means that you can refer to program locations by the symbols names you used for those locations in your program the names of variables routines labels and so on You do not have to use virtual addresses to refer to memory locations The debugger recognizes the syntax expressions data typing and other constructs of BASIC 3 2 Compiling and Linking to Prepare for Debugging The following example shows how to compile and link a BASIC program consisting of a single compilation unit named INVENTORY so that subsequently you will be able to use the debugger BASIC DEBUG INVENTORY LINK DEBUG INVENTORY Using the OpenVMS Debugger with BASIC 3 1 The DEBUG qualifier with the BASIC command instructs the compiler to write the debug symbol records assoc
178. Decimal Scalar String Descriptor Packed Decimal String Descriptor sece aged ened soak Ge oOa bc eae eRe SOM See ee Bons Part Ill Using HP BASIC Features on OpenVMS Systems 18 Advanced File Input and Output xii 18 1 18 1 1 18 1 2 18 1 3 18 1 4 18 1 5 18 1 6 18 1 7 18 1 8 18 1 9 18 2 18 2 1 RMS I O to Magnetic Tape 0 0 eee Allocating and Mounting a Tape 00 0 eee Opening a Tape File for Output 00 0000 Opening a Tape File for Input 005 Positioning a Tape 0 eee eee eee Writing Records toa File 0 0 0 0 eee Reading Records froma File 0 0 00 cee eeee Controlling Tape Output Format 0 Rewinding a Tape 0 0 ccc eee Closing a Piles s crror erin tiei EER ae Rae PORES ERG Res Device Specific I O 2 0 ees Device Specific I O to Unit Record Devices 17 1 17 1 17 2 17 2 17 2 17 3 17 3 17 4 17 6 17 6 17 7 17 7 17 8 17 9 17 10 17 10 17 11 17 11 18 1 18 2 18 2 18 3 18 3 18 4 18 5 18 5 18 6 18 6 18 7 18 7 18 2 2 Device Specific I O to Magnetic Tape Devices 18 2 2 1 Allocating and Mounting a Tape 5 18 2 2 2 Opening a Tape File for Output 18 2 2 3 Opening a Tape File for Input 18 2 2 4 Writing Records toa File 0 0000 eee eee 18 2 2 5 Reading Records froma File
179. E Compiler Directives 16 9 16 4 2 VARIANT Directive The VARIANT directive is a built in lexical function that returns an integer The value of this returned integer is determined by e The SET VARIANT command when a program is compiled in the VAX BASIC Environment e The VARIANT qualifier when a program is compiled from the system command level or from within the VAX BASIC Environment The VARIANT function returns the variant value set with either of these methods The default value for the VARIANT function is zero See Section 16 4 5 for an example of controlling compilation with VARIANT 16 4 3 ABORT Directive The ABORT directive terminates the compilation and displays a message you provide The text must be a quoted string literal This information is displayed to SYS ERROR and in the compilation listing if one is being created BASIC stops the compilation and terminates the listing file as soon as it encounters a ABORT directive and so BASIC does not perform syntax checking on the remainder of the program See Section 16 4 5 for an example of using ABORT 16 4 4 PRINT Directive The PRINT directive allows you to insert a message into your source code that the BASIC compiler displays at compile time The text must be a quoted string literal This information is displayed to SYS ERROR and in the compilation listing if one is being created BASIC prints the message specified as soon as it encounters a PRINT
180. E UNTIL IF or SELECT CASE block User Action Change the program logic so that it does not transfer control into a block JMPBADLIN jump to line number lt number gt is into a block Explanation INFORMATION The program transfers control to a line number within a FOR NEXT WHILE UNTIL IF or SELECT CASE block User Action This is an informational message However it is bad programming practice to transfer control into a block JMPINTDEF jump into DEF Explanation ERROR The program attempts to transfer control into a DEF block User Action Change the control statement you cannot transfer control into a DEF block except by invoking the function JMPOUTDEF jump out of DEF Explanation ERROR The program attempts to transfer control out of a DEF block User Action Change the control statement Use an EXIT DEF FNEXIT FNEND or END DEF statement to transfer control out of a DEF block Compile Time Error Messages A 47 JMPOUTHAN jump out of HANDLER Explanation ERROR The program attempts to transfer control out of an error handler User Action Change the control statement Use an EXIT HANDLER RETRY or CONTINUE statement to transfer control out of an error handler JMPOUTPRO jump out of program unit Explanation ERROR In a source file containing more than one program module a statement attempts to transfer control from one module into another User Action Change the statement that attempts to t
181. E coordinates must be within NDC space 0 0 to 1 0 Explanation ERROR The value of a coordinate is either less than 0 0 or greater than 1 0 User Action Supply a value from 0 0 to 1 0 CORSTAFRA corrupted stack frame Explanation ERROR An immediate mode statement was entered after a STOP statement was executed in the VAX BASIC Environment and something corrupted the stack User Action Check program logic to make sure that all array references are within array bounds This error can also be caused by loading non BASIC object modules in the VAX BASIC Environment Compile Time Error Messages A 19 COUONLALO COUNT clause only allowed with array LIST clause Explanation ERROR A COUNT clause was found on a SET INITIAL CHOICE statement that contains a LIST clause that does not contain a string array User Action Remove the COUNT clause or use the array form of the LIST clause COUVALCAN COUNT value cannot be greater than array size Explanation ERROR In the COUNT clause you specified a count that is larger than the size of the array that you supplied User Action Change either the COUNT value or the size of the array so that COUNT is less than or equal to the number of elements in the array DATTYPEXP data type required for variable lt name gt with EXPLICIT Explanation ERROR A program compiled with the TYPE EXPLICIT qualifier declares a variable without specifying a data type User Action Supply a dat
182. E block 9 12 CAUSE ERROR statement 15 20 CDD COMPILED_DEPENDS_ON relationship 21 9 21 10 CDD DEFAULT directory 21 7 CDD TOP 21 3 CDD Repository 21 1 to 21 30 array bounds 2 11 arrays 21 12 CDD TOP 21 3 CDD Repository 21 4 CDO 21 4 data definition 21 6 extracting 21 4 translating 21 6 data types 21 6 21 16 to 21 30 character string 21 21 complex 21 26 decimal string 21 27 fixed point 21 22 floating point 21 25 integer 21 22 other 21 29 dictionary directory 21 3 INCLUDE FROM CDD directive 21 4 NAME clause 21 15 object 21 3 CDD Repository cont d OLD_VERSION CDD_ARRAYS 21 13 path name 21 2 to 21 3 full 21 3 relative 21 3 STRUCTURE statement 21 6 subordinate field 21 6 support 21 1 to 21 30 variant 21 14 with the RECORD statement 21 4 CDD Repository definitions including 16 7 CDD Repository features 21 1 to 21 3 CDO format dictionary 21 7 CDO format directory 21 4 Centered fields with PRINT USING statement 14 15 Channels specifying with RMSSTATUS function 15 16 Characters nonprinting 4 5 Character set ASCII 4 5 BASIC 4 5 CHECK qualifier 2 6 CHR function 10 7 CLOSE statement ending file I O 18 6 ending I O to a tape 18 10 Command qualifiers with the BASIC command 2 1 Commas with PRINT USING statement 14 7 Comment fields 4 5 Common area defining 7 11 Common block 6 6 Common Data Dictionary See CDD Repository Common lang
183. E err_handler 900 END WHEN 1000 HANDLER err handler SELECT TRUE CASE ERR 11 AND ERL 790 Is error end of file at line 790 PRINT Completed CONTINUE CASE ERR 149 AND ERL 80 Is error not at end of file on line 80 PRINT CHECK ACCESS MODE CONTINUE CASE ELSE Let BASIC handle any other errors EXIT HANDLER 1500 END SELECT 2000 END HANDLER 32000 CLOSE 5 32767 END The results of ERL are undefined until an error occurs or if the error occurs in a subprogram not written in HP BASIC Although ERL remains defined as the line number of the last error even after control leaves the error handler it is poor programming practice to refer to this variable outside the scope of an error handler If you reference ERL in a compilation unit with line numbers code and data are included in your program to allow HP BASIC to determine ERL when an exception occurs If you do not need to reference ERL you can save program size and reduce execution time by compiling your program with the NOLINE qualifier Alpha BASIC uses the NOLINE qualifier by default to compile programs Even if you do not use any line numbers you can reduce execution time by compiling with the NOLINE qualifier Handling Run Time Errors 15 13 15 2 5 3 15 2 5 4 If an error occurs in a subprogram containing line numbers HP BASIC sets the ERL variable to the subprogram line number where the error was detected If the subprogram also executes an EXIT HANDLER
184. E filename filetype You can use the PRINT command to print the file you created C 2 CDD Repository HP BASIC supports CDD Repository The current version of CDD Repository is compatible with previous versions of CDD See Chapter 21 for more information about CDD Repository C 3 Database Management System DBMS DBMS is a multiuser general purpose CODASYL compliant database management system DBMS is used for accessing and administrating databases ranging in complexity from simple hierarchies to complex networks with multilevel relationships DBMS supports full concurrent access in a multiuser environment without compromising the integrity and security of your database For more information see the DBMS documentation C 4 Digital Test Manager for OpenVMS The Test Manager helps test software during development and maintenance This tool automates the organization execution and review of tests and allows several developers to use one set of tests at the same time With the Test Manager you can describe your tests organize them by assigning them to groups and choose combinations of tests to run by test name or by group The Test Manager executes the tests selected and then compares the result with the expected results For more information see the Guide to Test Manager for VMS Systems C 5 Code Management System for OpenVMS CMS The Code Management System for OpenVMS CMS is a program librarian for software development
185. E statement You can also refer to constants outside the program unit with the EXTERNAL statement In addition BASIC provides notation for binary octal decimal and hexadecimal constants For more information about named constants see the HP BASIC for OpenVMS Reference Manual 7 6 Operations with Multiple Data Types When an expression contains operands of different data types it is called a mixed mode expression Before a mixed mode expression can be evaluated the operands must be converted or promoted to a common data type The result of the evaluation can also be converted depending on the data type of the variable to which it is assigned Data Definition 7 3 When assigning values to variables HP BASIC converts the result of the expression to the data type of the variable If the value of the expression is outside the allowable range of the variable s data type HP BASIC signals Integer error or overflow Floating point error or overflow or DECIMAL error or overflow In general HP BASIC promotes operands with different data types to the lowest data type that can hold the largest and most precise possible value of either operand s data type HP BASIC then performs the operation in that data type and yields a result of that data type If the result of the expression is assigned to a variable HP BASIC converts the result to the data type of the variable For more information about multiple data types see th
186. E the file NOSRCLINE unsaved changes no source line debugging available Explanation WARNING The program in memory contains changes that have not been saved therefore no source line debugging will be available from this compilation User Action SAVE or REPLACE the file NOSUCHMAP no such MAP area lt name gt Explanation ERROR A REMAP statement names a nonexistent MAP area User Action Supply a MAP before executing the REMAP statement NOTIMP not implemented in this version Explanation ERROR The program attempted to use a feature that does not exist in this version of HP BASIC User Action Examine your program and remove the nonimplemented feature NOTMACROOM out of memory for macro definitions Explanation ERROR The limit on the number of macro definitions has been exceeded User Action Reduce the number of DEFINE definitions or undefine some previously defined macros with the 7UNDEFINE directive Compile Time Error Messages A 63 NOTPASSBY lt item gt may not be passed BY lt mechanism gt Explanation ERROR The program specifies an incorrect passing mechanism for a parameter s data type or an invalid parameter For example you cannot pass an entire array BY VALUE nor can you pass a label as a parameter User Action Specify a valid parameter or passing mechanism NOTRANS no main program Explanation WARNING When a RUN command was typed only subroutines or functions were
187. ECORD DECIMALSTRING UNSPECIFIED Cl DECIMAL 5 2 MY PACKED DECIMAL PACKED DECIMAL Cl GROUP MY ZONED NUMERIC ZONED NUMERIC Cl STRING STRING VALUE Cl END GROUP Cl GROUP MY UNSIGNED NUMERIC UNSIGNED NUMERIC Cl STRING STRING VALUE Cl END GROUP T ci GROUP MY LEF SEP NUMERIC NUMERIC LEFT P SEPARATE Cl STRING STRING VALUE Cl END GROUP T Cl GROUP MY LEFT OVPNCH NUMERIC NUMERIC LEFT E B OVERPUNCHED Cl STRING STRING VALUE Cl END GROUP T Cl GROUP MY RIGHT SEP NUMERIC NUMERIC RIGHT _ SEPARATE Cl STRING STRING VALUE Cl END GROUP T ci GROUP MY RIGHT OVPNCH NUMERIC NUMERIC RIGHT E OVERPUNCHED Cl STRING STRING VALUE Cl END GROUP T onl END RECORD SBASIC I CDDSUBGRO SBASIC I CDDSUBGRO SBASIC I CDDSUBGRO BASIC I CDDSUBGRO BASIC I CDDSUBGRO SBASIC I CDDSUBGRO 21 9 5 Other Data Types data type in CDD Repository not supported substituted group for DECIMALSTRING MY ZONED NUMERIC data type in CDD Repository not supported substituted group for DECIMALSTRING MY UNSIGNED NUMERIC data type in CDD Repository not supported substituted group for DECIMALSTRING MY LEF SEP NUMERIC data type in CDD Repository not supported substituted group for DECIMALSTRING MY LEFT OVPNCH NUMERIC data type in CDD Repository not supported substituted group for DECIMALSTRING MY RIGHT SEP NUMERIC data type in CDD Repository not supported substitut
188. ECORDs and GROUPs items can be unaligned if the size of a RECORD or GROUP is not a multiple of the alignment requirements of that RECORD or GROUP For example if a RECORD has a natural alignment of quadword the size of the RECORD must be a multiple of eight Otherwise all array elements after the first might start on an unaligned boundary Avoid unaligned accesses by padding the end of the RECORD with fill items e WARNINGS ALL is the same as WARNINGS INFORMATIONAL WARNINGS ALIGNMENT e WARNINGS NONE is the same as NOWARNINGS 2 1 3 Declining Qualifiers and Their Recommended Replacements The following qualifiers are declining features BYTE DOUBLE GFLOAT LONG SINGLE TIE WORD It is recommended that you replace them with newer qualifiers as follows Old Qualifier Recommended Replacement BYTE INTEGER_SIZE BYTE DOUBLE REAL_SIZE DOUBLE GFLOAT REAL_SIZE GFLOAT LONG INTEGER_SIZE LONG SINGLE REAL_SIZE SINGLE TIE Move to using entirely native code WORD INTEGER_SIZE WORD See the description of the NO FLAG NO DECLINING qualifier in this chapter Also see the descriptions of the INTEGER_SIZE and REAL_SIZE qualifiers in this chapter The old qualifiers are described in the HP BASIC for OpenVMS Reference Manual 2 20 Developing HP BASIC Programs 2 1 4 Compiler Listings A compiler listing provides information that can help you debug your HP BASIC program To generate
189. ECwindows Motif declarations is required to build the programs The steps to build and run the HELLOMOTIF example are 1 Copy the needed files into your current directory COPY DECWSEXAMPLES BASICSHELLOMOTIF 2 Build the Resource UID file UIL MOTIF BASICSHELLOMOTIF UIL 3 Compile and link the BASIC program e Use the following example for DECWindows Motif V1 1 BASIC BASICSHELLOMOTIF LINK BASICSHELLOMOTIF SYSSINPUT OPTIONS SYSSLIBRARY DECWSDXMLIBSHR EXE SHARE SYSSLIBRARY DECWSXMLIBSHR EXE SHARE SYSSLIBRARY DECWSXTSHR EXE SHARE Z e Use the following example for DECWindows Motif V1 2 Using DECwindows Motif Bindings with BASIC 22 3 BASIC BASICSHELLOMOTIF LINK BASICSHELLOMOTIF SYSSINPUT OPTIONS SYSSLIBRARY DECWSDXMLIBSHR12 EXE SHARE SYSSLIBRARY DECWSMRMLIBSHR12 EXE SHARE SYSSLIBRARY DECWSXMLIBSHR12 EXE SHARE SYSSLIBRARY DECWSXTLIBSHRR5 EXE SHARE Z You may want to create an options file with the previously mentioned shareable libraries in it 4 If you are not running on a workstation make sure that your display is set correctly for example SET DISPLAY CREATE NODE xxxx xxxx is the node name of a workstation with appropriate graphic capability 5 Run the application RUN BASICSHELLOMOTIF Note The UID file must be kept in the same directory as the EXE file when run This program looks in the current directory for the UID file 6 Then follow th
190. ED SIZE DIGITS FRACTION 21 22 Using CDD Repository with BASIC BASE SCALE In CDDL if integer data types are not specified as being signed or unsigned the default is unsigned HP BASIC supports only signed BYTE signed WORD signed LONGWORD and signed QUADWORD integers If a CDD Repository data definition containing an unsigned BYTE WORD LONGWORD or QUADWORD integer is extracted HP BASIC signals the informational message Datatype in CDD Repository not supported substituted group for lt field name gt and creates a group to contain the field Because the group name is the same as the CDD Repository field name HP BASIC assigns a new name to the field This is shown in the following CDDL data definition and corresponding HP BASIC RECORD statement CDDL Definition define record CDDS top basic integers description is Test of selected integer data types basicint structure my byte datatype is signed byte my ubyte datatype is byte my word datatype is signed word my uword datatype is unsigned word my long datatype is signed longword my ulong datatype is unsigned longword end basicint structure end integers Translated RECORD Statement 1 INCLUDE FROM CDD CDDSTOP BASIC INTEGERS Cl Test of selected integer data types ci RECORD BASICINT UNSPECIFIED Cl BYTE MY BYTE SIGNED BYTE Cl GROUP MY UBYTE UNSIGNED BYTE Cl BYTE BYTE VALUE Cl END GROUP Cl WORD MY WORD SIGNED WORD Cl GROUP MY UWORD
191. ER X INTEGER Y DECLARE INTEGER temp IF X gt Y THEN temp X X Y Y temp ELSE EXIT SUB END IF END SUB FUNCTION Subprograms A FUNCTION subprogram is a program module that returns a value and can be separately compiled It must be delimited by the FUNCTION and END FUNCTION statements You use the EXTERNAL statement to name and explicitly declare the data type of an external function The END FUNCTION statement does the following e Marks the end of a function subprogram e Does not affect I O operations or files e Releases the storage allocated to local variables e Optionally specifies a return value for the function e Returns control to the calling program Program Segmentation 12 3 The EXIT FUNCTION statement immediately returns program control to the statement that invoked the function and optionally returns the function s return value It is equivalent to an unconditional transfer to the END FUNCTION statement You can specify an expression with both the END FUNCTION and EXIT FUNCTION statements which is another way of returning a function value This expression must match the function data type and it supersedes any function assignment For more information see the HP BASIC for OpenVMS Reference Manual The following function returns the volume of a sphere of radius R If this function is invoked with an actual parameter value less than or equal to zero the function returns zero FUNCTION REAL Sphere volume
192. ERIC e LEFT SEPARATE NUMERIC e RIGHT OVERPUNCHED NUMERIC e RIGHT SEPARATE NUMERIC e PACKED DECIMAL Using CDD Repository with BASIC 21 27 e UNSIGNED NUMERIC e ZONED NUMERIC HP BASIC supports only the PACKED DECIMAL decimal string data type which corresponds to the HP BASIC DECIMAL data type For all other decimal string data types HP BASIC creates a group with the same name as the CDD Repository subordinate field and creates a string record component to contain the field For example CDDL Definition define record CDD top basic decimalstring description is test decimal string data types decimalstring structure my_packed_decimal datatype is packed decimal size is 5 digits 2 fractions my zoned numeric datatype is zoned numeric size is 6 digits 2 fractions my unsigned numeric datatype is unsigned numeric size is 8 digits 4 fractions my lef sep numeric datatype is left separate numeric 1 size is 10 digits 3 fractions my left ovpnch numeric datatype is left overpunched numeric size is 5 digits 2 fractions my_right_sep numeric datatype is right separate numeric size is 3 digits 1 fractions my right ovpnch numeric datatype is right overpunched numeric B size is 4 digits 2 fractions end decimalstring structure end decimalstring 21 28 Using CDD Repository with BASIC Translated RECORD Statement 1 INCLUDE FROM CDD CDDS TOP BASIC DECIMALSTRING cl test decimal string data types Cl R
193. ERR Trap buffer overflow CASE 161 PRINT Record too long CONTINUE Trap end of file on device CASE 11 PRINT End of file CONTINUE CASE ELSE EXIT HANDLER END SELECT END HANDLER CLOSE 1 END PROGRAM Note that ON ERROR statements are not allowed within protected regions or handlers For compatibility issues related to ON ERROR statements see Section 15 3 Exiting from Handlers After processing an error a handler typically clears the error so that program execution can continue HP BASIC provides the following statements that clear the error condition and exit from the handler RETRY CONTINUE END HANDLER END WHEN 15 6 Handling Run Time Errors These statements differ from each other in that they revert control of program execution to different points in the program Examples of these statements are included in the following sections An additional statement EXIT HANDLER is provided to allow you to exit from a handler with the error still pending The END HANDLER statement identifies the end of the block of statements in the handler The END WHEN statement marks the end of the protected region when a detached handler is used it marks the end of the handler when an attached handler is used If the handler does not process an error with an EXIT HANDLER RETRY or CONTINUE statement the error is cleared by the END HANDLER or END WHEN statement however processing continues with the statement immediately after the pro
194. Explanation ERROR A CDD Repository field can be either variable or fixed length HP BASIC supports only fixed length fields User Action Change the CDD Repository definition CHAEXPMUS channel expression must be numeric Explanation ERROR The program contains a nonnumeric channel expression for example PUT A User Action Change the channel expression to be numeric CHALINCLA CHAIN does not support line number clause Explanation ERROR A CHAIN statement contains a LINE keyword and a line number argument User Action Remove the LINE keyword and the line number argument CHANOTALL CHANGES not allowed on primary key Explanation ERROR The PRIMARY KEY clause in an OPEN statement specifies CHANGES User Action Remove the CHANGES keyword you cannot change the value of a primary key CHASTAAMB CHANGE statement is ambiguous Explanation ERROR A string variable and a numeric array have the same name in a CHANGE statement User Action Change the name of the string variable or the numeric array A 16 Compile Time Error Messages CLIPMUSBE clipping must be set to ON or OFF Explanation ERROR You specified an invalid value in the SET CLIP statement User Action Specify one of the values listed in the message CLOSEIN error closing lt file name gt as input Explanation ERROR An error was detected while closing an input file User Action Take corrective action based on the associated
195. G returns a null string e Ifthe ending character position is greater than the length of the string SEG returns all characters from the starting character position to the end of the string e Ifthe starting character position is equal to the ending character position SEG returns the character at the starting position You can replace part of a string by using the SEG function with the string concatenation operator In the following example when HP BASIC creates C it concatenates the first two characters of A the 3 letter string XYZ and the last two characters of A The original contents of A do not change AS ABCDEFG C SEG A 18 2 XYZ SEG A 6 7 PRINT C PRINT A END Output ABXYZFG ABCDEFG You can use similar string expressions to replace characters in any string If you do not change the length of the target string use the MID assignment statement to perform string replacement A general formula to replace characters in positions n through m of string A with characters in B is as follows C SEG A 1 n 1 B SEG A m 1 LEN A The following example replaces the sixth to ninth characters of the string ABCDEFGHIJK with 123456 String Handling 11 13 ABCDEFGHIJK BS 123456 SEG A 1 5 BS SEGS AS 10 LEN AS PRINT C PRINT A PRINT B END Output ABCDE123456JK ABCDEFGHIJK 123456 The following formulas are more specific application
196. GET statements on terminal format files or virtual array files For sequential files a sequential GET retrieves the next record in the file For relative files a sequential GET retrieves the next existing record For indexed files a sequential GET retrieves the record with the next ascending or descending value in the current key of reference depending on that key s collating sequence 13 16 File Input and Output Table 13 2 shows the current record and next record pointers after a GET operation Note that the values of these pointers vary depending on whether or not the previous operation was a FIND Table 13 2 Record Context After a GET Operation Record Access File Current Mode Type Record Next Record Sequential GET Sequential Record found Current record 1 with FIND Relative Record found Next existing record Indexed Record found Next record in current key Sequential GET Sequential Next record Next record 1 without FIND Relative Next existing Next existing record 1 record Indexed Next record in Record following next current key record in current key Random GET All Record specified Next record in succession If you precede a sequential GET operation with a FIND operation the current record is the one located by FIND If you do not perform a FIND operation before a sequential GET operation the current record is the next sequential record The following example shows the use of the GET operation to sequentially a
197. GPAS illegal argument passing mechanism Explanation ERROR The program specifies an invalid argument passing mechanism for example passing strings or arrays BY VALUE or passing an entire virtual array User Action Check all elements for the proper parameter passing mechanism A 36 Compile Time Error Messages ILLCALFUN illegal CALL of a DECIMAL HFLOAT or STRING function Explanation ERROR You attempted to use the CALL statement to invoke either a DECIMAL HFLOAT or STRING function User Action Invoke the function not using the CALL statement ILLCHA illegal character lt ASCII code gt Explanation WARNING The program contains illegal or incorrect characters User Action Examine the program for correct usage of the HP BASIC character set and possibly delete the character ILLCHAEXT illegal character lt ASCII code gt in external name Explanation ERROR The external symbol in an EXTERNAL FUNCTION or CONSTANT declaration contains an invalid character User Action Remove the invalid character External names can use only printable ASCII characters ASCII values in the range 32 to 126 inclusive ILLCHAIDE illegal character lt ASCII value gt in IDENT directive Explanation WARNING A IDENT directive contains an illegal character with the reported ASCII value User Action Remove the illegal character ILLCONTYP illegal constant type Explanation ERROR The program contains an invalid declarati
198. HP BASIC for OpenVMS User Manual Order Number AA HY15F TK January 2005 This manual describes how to develop HP BASIC programs and use HP BASIC features on HP OpenVMS Industry Standard 64 and HP OpenVMS Alpha systems Revision Update Information This revised manual supersedes the Compaq BASIC OpenVMS Alpha and VAX Systems User Manual Version 1 4 Software Version HP BASIC Version 1 6 for OpenVMS Systems Operating System and Version OpenVMS 164 Version 8 2 or higher OpenVMS Alpha Version 7 1 or higher with IEEE floating point support OpenVMS Alpha Version 6 1 or higher without IEEE floating point support Hewlett Packard Company Palo Alto California Copyright 2005 Hewlett Packard Development Company L P Confidential computer software Valid license from HP required for possession use or copying Consistent with FAR 12 211 and 12 212 Commercial Computer Software Computer Software Documentation and Technical Data for Commercial Items are licensed to the U S Government under vendor s standard commercial license The information contained herein is subject to change without notice The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services Nothing herein should be construed as constituting an additional warranty HP shall not be liable for technical or editorial errors or omissions contained herein Intel and Itanium are trademarks
199. IO Memory management violation ERR 35 Explanation The program attempted to read or write to a memory location to which it was not allowed access This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action If the program was compiled with NOCHECK it may be exceeding an array bound recompile with CHECK Otherwise check program logic MISSPEFEA Missing special feature ERR 66 Explanation The program attempts to use an unavailable SYS call User Action See the appropriate RSTS E SYS call documentation MOVOVEBUF Move overflows buffer ERR 161 Explanation In a MOVE statement the combined length of elements in the I O list exceeds the size of the record just read or the size of the buffer User Action Reduce the size of the I O list or increase the file s RECORDSIZE NEGFILSTR Negative fill or string length ERR 166 Explanation A MOVE statement I O list contains a FILL item or string length with a negative value User Action Change the FILL item or string length value to be greater than or equal to zero B 20 Run Time Messages NEGZERTAB negative or zero TAB ERR 176 Explanation The program attempted a zero or negative TAB This error is signaled only for programs compiled with the ANSI_STANDARD qualifier User Action Change the argument to the TAB statement NETOPERR network operation error ERR 182 Explanation The program attempt
200. L function returns only SINGLE DOUBLE GFLOAT SFLOAT TFLOAT XFLOAT or HFLOAT values INVSUBTYP lt data type gt is not a subtype of lt data type gt Explanation ERROR The program contains an invalid declaration containing contradictory type declarations for example DECLARE REAL BYTE User Action Supply a valid declaration Use only valid integer subtypes for INTEGER and only valid floating point subtypes for REAL IS_NOTDYN lt name gt is not a DYNAMIC MAP variable of MAP lt name gt Explanation ERROR A REMAP statement names a variable that was not named in the MAP DYNAMIC statement for that MAP User Action Remove the variable from the REMAP statement or name the variable in the MAP DYNAMIC statement for that map A 46 Compile Time Error Messages ITEMUSAPP ITERATE must appear within a loop Explanation ERROR The program contains an ITERATE statement that is not within a FOR NEXT WHILE or UNTIL loop User Action Remove the ITERATE statement or surround it with a loop JMPBADBLO jump to line number lt line number gt is into a controlled block Explanation ERROR The program attempts to transfer control to a WHEN block or associated handler User Action Change the program logic so that it does not transfer control to a WHEN block or associated handler JMPBADLAB jump to label lt label gt is into a block Explanation ERROR The program attempted to transfer control into a FOR NEXT WHIL
201. LINSTY Illegal line style number ERR 274 Explanation The specified line style number is less than or equal to zero User Action Specify a valid line style value greater than zero ILLNETOPE Illegal network operation ERR 190 Explanation The program tries to mix GET and PUT operations or PRINT and INPUT operations on a remote terminal format file User Action Change the file organization when opening the file to be sequential variable ILLNUM Illegal number ERR 52 Explanation A value supplied to a numeric variable is incorrect for example ABC and 1 2 are illegal numbers User Action Supply numeric values of the correct form ILLOPE Illegal operation ERR 141 Explanation The program attempts to e DELETE a record in a sequential file e UPDATE a record on a magtape file e Rewind a process permanent file e DELETE a record in a read only file e Assign a value to a virtual array element in a read only file e Perform a MARGIN operation on VIRTUAL file Run Time Messages B 13 Transpose a matrix or perform a matrix multiplication with the same array as source and destination Perform an invalid operation on a VIRTUAL file for example using GET and PUT on a VIRTUAL file then attempting to reference a virtual array dimensioned on that file User Action Change the illegal operation ILLPICOPE Illegal picture operation ERR 258 Explanation The program attempts to change a transforma
202. LL item specifies a nonnumeric or negative repeat count for example FILL A or FILL 3 User Action Supply a valid repeat count Compile Time Error Messages A 77 SCAFACINH SCALE factor inhibits optimization Explanation INFORMATION This error is reported only when the SETUP qualifier is in effect Specifying a scale factor prevents optimization of the compiler generated code User Action Compile the program without specifying a scale factor SCAFILMUS ANALYSIS file must be random access no ANA file produced Explanation WARNING The file specification on the ANALYSIS_ DATA qualifier specifies a nonrandom access device therefore no analysis data file will be produced HP BASIC ignores the ANALYSIS_DATA qualifier and continues compilation User Action Specify a random access device on the file specification on the ANALYSIS_DATA qualifier SCALEO scale factor used is 0 for single precision Explanation WARNING An attempt was made to set the SCALE factor while in single precision User Action Set the precision to REAL_SIZE DOUBLE You cannot use scaling when in single precision SCANOTANS ANALYSIS_DATA qualifier not allowed with ANSI Explanation ERROR The ANALYSIS_DATA qualifier conflicts with the ANSI_STANDARD qualifier User Action Specify either the ANALYSIS_DATA qualifier or the ANSI_ STANDARD qualifier but not both SCAOUTRAN SCALE is out of range Valid is 0 to 6 Explanation ER
203. LON KEY lt name gt in MAP lt name gt is too long max is 255 Explanation ERROR A KEY variable is longer than 255 characters User Action Reduce the length of the KEY variable The maximum key length is 255 characters Compile Time Error Messages A 49 KEYWORINC keyword inconsistent with lt OPEN clause gt clause Explanation ERROR An OPEN statement contains an ALLOW ACCESS or RECORDTYPE clause whose keyword argument is invalid for example ACCESS FORTRAN User Action Change the clause argument to a valid keyword for that clause LABNOTDEF label lt label gt not defined Explanation ERROR The program tries to transfer control to a nonexistent label User Action Define the label before transferring control to it LABNOTLAB label lt name gt does not label an active block statement Explanation ERROR An EXIT statement in a loop if then else or SELECT CASE block specifies a label that does not refer to that block User Action Change the program so that the label actually refers to the block in which the EXIT statement occurs LABNOTLOO label lt name gt does not label an active loop statement Explanation ERROR In a loop an EXIT or ITERATE statement specifies a label that does not refer to that loop User Action Change the program so that the label actually refers to the loop in which the EXIT or ITERATE statement occurs LANFEADEC language feature is declining Explanation INFORMATION
204. MS prefixes the records with any count bytes PUT 6 COUNT 56 Reading Records from a File The GET statement reads records into the buffer The following program reads a record into the buffer prints a string field and rewinds the file before closing Successive GET operations read successive records HP BASIC signals the error End of file on device ERR 11 if you encounter a tape mark during a GET operation If you trap this error and continue you can skip over any tape marks The system variable RECOUNT is set to the number of bytes transferred after each GET operation OPEN MT1 FOR INPUT AS FILE 1 ACCESS READ GET 1 MOVE FROM 1 AS RECOUNT PRINT A RESTORE 1 CLOSE 1 Advanced File Input and Output 18 9 18 2 2 6 18 2 2 7 18 2 3 Rewinding a Tape When you mount a magnetic tape the system will position the tape at the load point BOT Your program can rewind the tape during program execution with the RESTORE statement For example OPEN MT1 FOR OUTPUT AS FILE 2 ACCESS READ PUT 2 RESTORE 2 INPUT NEXT RECORD NXTRECBB If you rewind a tape opened without ACCESS READ before closing it you erase all data written before the RESTORE operation Closing a Tape The CLOSE statement ends I O to the tape For example the following statement ends input and output to the tape open on channel 12 CLOSE 128 If you opened the file with ACCESS READ CLOSE has no further effect If
205. NAL LONG CONSTANT 10 WRITEVBLK continued on next page Using BASIC in the Common Language Environment 19 21 Example 19 4 Cont Program Displaying the QIOW System Service Routine Declare the parameters DECLARE STRING my_ term out_str amp WORD term chan counter stat _block 3 amp LONG ret_status msg_len car_cntrl out str Successful QIOW output my term SYSSCOMMAND msg len LEN out str car cntrl 32 Assign a channel to the terminal ret status SYSSASSIGN my term term chan CALL LIBSSTOP ret_status BY VALUE IF ret_status AND 1 0 Output the message four times FOR counter 1 to 4 ret status SYSSQIOW term chan BY VALUE I0 WRITEVBLK BY VALUE amp stat block BY REF out str BY REF amp msg len BY VALUE car cntrl BY VALUE CALL LIBSSTOP ret status BY VALUE IF ret status AND 1 03 CALL LIB STOP stat block 0 BY VALUE amp IF stat_block 0 and 1 0 NEXT counter END Output Successful SQIOW output Successful SQIOW output Successful SQIOW output Successful SQIOW output In addition to invoking the function SYS QIOW the previous example also invokes the function SYS ASSIGN This function provides a process with an T O channel so that input and output operations can be performed on a logical device name my_term As soon as SYS ASSIGN is invoked and a path is established to the device a counter is set up to invoke the QIOW function four times Once all I
206. NT USING center ABCDE END Output A AB ABC ABCD ABCDE If there are more characters than places in the field BASIC left justifies and truncates the string on the right Extended Fields An extended field contains a single quotation mark followed by one or more Es The extended field is the only field that automatically prints the entire string In addition e If the string is smaller than the format field BASIC left justifies the string as in a left justified field e Ifthe string is longer than the format field BASIC extends the field and prints the entire string PRINT USING E THE QUICK BROWN PRINT USING EEEEEEE FOX END Output THE QUICK BROWN FOX Formatting Output with the PRINT USING Statement 14 15 The following example uses left justified right justified centered and extended fields PRINT USING LLLLLLLLL THIS TEXT PRINT USING LLLLLLLLLLLLLL SHOULD PRINT PRINT USING LLLLLLLLLLLLLL AT LEFT MARGIN PRINT USING RRRR 1 2 3 4 PRINT USING RRRR 1 2 3 PRINT USING RRRR 1 2 PRINT USING RRRR 1 PRINT USING CCCCCCCCC A PRINT USING CCCCCCCCC ABC PRINT USING CCCCCCCCC ABCDE PRINT USING CCCCCCCCC ABCDEFG PRINT USING CCCCCCCCC ABCDEFGHI PRINT USING LLLLLLLLLLLLLLLLL YOU ONLY SEE PART OF THIS PRINT USING E YOU CAN SEE ALL OF THE LINE WHEN IT IS EXTENDED END Output THIS TE
207. Not at end of file 150 NO_PRIKEY No primary key specified 151 KEYFIEBEY Key field beyond end of record 152 ILLRECACC Illogical record accessing 153 RECALREXI Record already exists 154 RECBUCLOC Record bucket locked 155 RECNOTFOU Record not found 156 SIZRECINYV Size of record invalid 157 RECFILTOO Record on file too big 158 PRIKEYOUT Primary key out of sequence continued on next page Run Time Messages B 33 Table B 1 Cont BASIC Run Time Errors Error Number Explanation 159 KEYLARTHA Key larger than record 160 FILATTNOT File attributes not matched 161 MOVOVEBUF Move overflows buffer 162 CANNOT OPEN FILE 164 TERFORFIL Terminal format file required 166 NEGFILSTR Negative fill or string length 168 ILLALLCLA Illegal ALLOW clause 170 INDNOTFUL Index not fully optimized 171 RRVNOTFUL RRV not fully updated 173 INVRFAFIE Invalid RFA field 174 FILEXPDAT File expiration date not yet reached 175 NODNAMERR Node name error 176 NEGTABNOT Negative TAB not allowed 177 TOOMUCDAT Too much data in record 178 ERRFILCOR Error on OPEN file corrupted 179 UNEFILDAT Unexpired file date 181 DECERR Decimal error or overflow 182 NETOPERR Network operation error 183 REMOVEBUF REMAP overflows buffer 185 RECOVEMAP RECORDSIZE overflows MAP buffer 186 IMPERRHAN Improper error handling 187 ILLRECLOC Illegal record locking 189 TOOLITDAT Too little data in record 190 ILLNETOPE Illegal network o
208. OR An error was detected in attempting to open a file for input User Action Make sure the file specification is correct OPENOUT error opening lt file name gt as output Explanation ERROR An error was detected in attempting to open a file for output User Action Supply a valid file specification or take corrective action based on the associated message OPNCLAVAL OPEN clause lt clause gt value greater than lt number gt Explanation ERROR An OPEN statement contains a RECORDSIZE FILESIZE EXTENDSIZE WINDOWSIZE BLOCKSIZE BUCKETSIZE or BUFFER clause whose argument is too large User Action Supply a smaller value for the argument OPNDUPCLA duplicate OPEN clause Explanation WARNING An OPEN statement contains more than one clause of the same type User Action Remove one of the clauses OPNILLCLA lt clause gt is an unsupported OPEN clause Explanation ERROR An OPEN statement specifies invalid attributes for the file for example CLUSTERSIZE on OpenVMS systems or uses the keyword COMMON in an I O clause User Action Substitute valid attributes for the file or remove the COMMON keyword OPNINCCLA lt keyword gt keyword is inconsistent with file organization Explanation ERROR An OPEN statement contains a clause that is not appropriate for the specified file organization for example opening a relative file with the ACCESS APPEND clause User Action Remove the inconsistent clause A
209. ORD component reference uses an invalid record name for example A B when A is not a RECORD name User Action Change the erroneous reference A 60 Compile Time Error Messages NAMTOOLON name is too long changed to lt name gt Explanation WARNING A variable or array name is longer than 31 characters HP BASIC truncates the name to 31 characters and continues compilation so that other errors can be detected The actual program line remains unchanged and no object file is produced User Action Reduce the length of the variable name to 31 or fewer characters NEGFILSTR negative FILL or string length Explanation ERROR The program contains a negative FILL specification or string length User Action Change the FILL specification or string length to a positive number NESFORLOO nested FOR loops with same control variable lt name gt Explanation ERROR The program contains nested FOR NEXT loops that use the same index variable User Action Change the index variable for all but one of the loops NOBASFRAM no BASIC frame on stack Explanation ERROR HP BASIC could not find a valid stack frame This could be caused by running a program with CHECK NOBOUNDS or by a non BASIC subprogram User Action Debug the program before running with CHECK NOBOUNDS or check the logic of the non BASIC subprogram NODESCALL no descriptor allocated for array lt name gt Explanation ERROR An immediate mode statement requi
210. P BASIC strips all trailing nulls from the string Therefore when you access an element in a string virtual array the string never has trailing nulls In the following example the first two lines dimension a string virtual array and open a file on channel 1 The third line assigns a 10 character string to the first element of this string array and to the variable A This 10 character string consists of ABCDE plus five null characters The PRINT statements show that the length of A is 10 while the length of test 1 is only 5 because HP BASIC strips trailing nulls from string array elements DIM 1 STRING test 5 OPEN TEST AS FILE 1 ORGANIZATION VIRTUAL AS test 1 ABCDE STRINGS 5 0 PRINT LENGTH OF A IS LEN AS PRINT LENGTH OF TEST 1 IS LEN test 1 END Output LENGTH OF A IS 10 LENGTH OF TEST 1 IS 5 Although the storage for string virtual array elements is fixed the length of a string array element can change because HP BASIC strips the trailing nulls whenever it retrieves a value from the array 11 5 Assigning String Data 11 5 1 To assign string data you use the LET LSET RSET and MID statements The following sections describe how to use these statements LET Statement The LET statement assigns string data to a string variable The keyword LET is optional Again LSET is more efficient than LET when changing a dynamic string variable In the following example B is a string
211. R You specified an invalid value for the text precision of the SET TEXT FONT statement User Action Specify one of the values listed in the message THEMUSFOL THEN directive must follow a lexical expression Explanation ERROR A IF directive contains a lexical expression that is not immediately followed by a THEN clause User Action Supply a THEN clause THEN ELSE and WEND IF are required in a IF directive TOMCHINFO extra information about command line has been ignored Explanation INFORMATION You supplied an argument to a CONTINUE EXIT IDENTIFY or SCRATCH command These commands do not accept arguments HP BASIC ignores the extra data and executes the command User Action Remove the argument from the command TOOFEWARG too few arguments Explanation ERROR The invocation of an HP BASIC built in function contains too few arguments User Action Supply the correct number of arguments to the function TOOMANARG too many arguments Explanation ERROR The invocation of an HP BASIC built in function contains too many arguments User Action Supply the correct number of arguments to the function Compile Time Error Messages A 85 TOOMANIND too many array indices active Explanation ERROR A subscript expression contains more than 100 array indices between the open parenthesis and the close parenthesis User Action Reduce the number of active array indices TOOMANKEY too many keys lim
212. R INPUT AS FILE 1 LINPUT 1 passenger name OPEN RESER LST FOR INPUT AS FILE 23 amp ORGANIZATION INDEXED MAP RES ACCESS READ amp PRIMARY passenger name FIND 2 KEY 0 EQ passenger_name RECEIVING MSGS Passenger reservation confirmed PRINT 1 RECEIVING MSG END WHEN HANDLER err trap IF ERR 155 THEN RECEIVING MSGS Reservation does not exist ELSE EXIT HANDLER END IF END HANDLER CLOSE 23 1 END PROGRAM Example 1 requests a passenger name and sends it to the mailbox Example 2 looks up the name in an indexed file If the passenger name exists Example 2 writes the confirmation message to the mailbox If the passenger name does not exist the error handler writes an alternate message Example 1 then reads the mailbox and returns the result HP BASIC treats the mailbox as a sequential file You write to the file with the PRINT or PUT statement and read it with the INPUT LINPUT or GET statement 18 14 Advanced File Input and Output When either program closes the mailbox the other program receives an end of file error message when it attempts to read the mailbox Note All mailbox operations are synchronous Control does not pass back from a mailbox operation such as a PUT to your program until the other program completes the corresponding operation such as a GET 18 4 Network I O 18 4 1 If your system supports DECnet for OpenVMS VAX facilities and your computer is o
213. RESUME statement has been found in a WHEN block or an associated error handler User Action Remove the RESUME statement from the WHEN block or associated error handler RESORDLIN RESEQUENCE cannot change the order of or delete lines Explanation ERROR The RESEQUENCE command specifies invalid source program changes User Action Supply a valid RESEQUENCE command RETCONMUS RETRY and CONTINUE must appear in error handlers Explanation ERROR A RETRY or CONTINUE statement is not in an error handler associated with a WHEN block protected region User Action Remove the RETRY or CONTINUE statement RFAEXPREQ RFA expression required Explanation ERROR A GET BY RFA statement contains an expression that is not of the RFA data type User Action Supply a valid RFA expression RFANOTALL RFA not allowed in this context Explanation ERROR The program attempts to use an RFA expression in an arithmetic expression or other invalid context User Action Remove the RFA expression You can use the RFA data type only in file I O in an assignment statement or in a comparison ROUSUPDEC ROUNDing supported only for DECIMAL Explanation ERROR Rounding was specified for a non DECIMAL data type in 1 a compiler command 2 a qualifier to the BASIC DCL command or 3 an OPTION statement User Action Specify rounding only for the DECIMAL data type RPTCOUMUS repeat count must be positive numeric Explanation ERROR A FI
214. RMS sequential relative and indexed files For sequential variable and stream files a sequential PUT operation adds a record at the end of the file For sequential fixed and relative files PUT writes records sequentially or randomly depending on the presence of a RECORD clause For indexed files RMS stores records in order of the primary key s collating sequence therefore you do not need to specify a random or sequential PUT Table 13 3 shows the record context after both random and sequential PUT operations Table 13 3 Record Context After a PUT Operation Record Access File Current Mode Type Record Next Record Sequential PUT Sequential None End of file Sequential PUT Relative None Next record Sequential PUT Indexed None Undefined Random PUT Relative None Unchanged After a PUT operation the current record pointer has no value However the value of the next record pointer changes depending on the file type and the record access mode used with the PUT operation In a sequential stream or variable file records can only be added at the end of the file therefore the next record after PUT is the end of the file In a relative sequential or fixed file the next record after a PUT operation is the next logical record The following example opens a sequential file with ACCESS APPEND specified For sequential files this is almost identical to ACCESS WRITE The only difference is that with ACCESS APPEND BASIC positions the fil
215. RNING A CALL statement external function reference or EXTERNAL statement specifies a BY clause but does not specify a formal parameter list User Action Remove the BY clause or supply a parameter list PATNOTREC path name does not specify a CDD Repository record Explanation ERROR The INCLUDE directive contains an invalid path name for a record definition User Action Supply a valid path name for a record definition PICWHINOT exit from PICTURE while not in PICTURE Explanation ERROR An EXIT PICTURE statement was found in a module that is not a PICTURE subprogram User Action Remove the EXIT PICTURE statement PLACENODESIGN placeholders illegal without DESIGN PLACEHOLDERS Explanation ERROR A placeholder occurred in the source file and the DESIGN PLACEHOLDERS option was not specified User Action Recompile the program and specify the qualifier PLACENODOT repetition of pseudocode placeholders not allowed Explanation ERROR A pseudocode placeholder was syntactically incorrect User Action You should remove the trailing periods following the pseudocode placeholder PLACENOEXE placeholders detected source cannot be executed Explanation ERROR The source code for a RUN command in immediate mode contained at least one placeholder therefore it could not be executed User Action You should remove the placeholders from the source code and reissue the command A 70 Compile Time Error Message
216. ROGRAM call fortran The BASIC main program prints the array before calling the subroutine EXTERNAL SUB forsub WORD DIM BY REF DIM WORD array x 1 TO 10 1 TO 5 FOR column 1 TO 5 FOR row 1 TO 10 array x row column 10 row column PRINT array x row column NEXT row PRINT NEXT column PRINT CALL forsub array_x BY REF END PROGRAM Example 19 2 FORTRAN Subprogram C The FORTRAN subprogram receives C and then prints the same array SUBROUTINE forsub f array INTEGER 2 f_array 5 10 DO 20 row 1 5 TYPE f array row column column 1 10 20 CONTINUE RETURN END You can pass only the data types that HP BASIC and FORTRAN have in common You cannot pass a complex number from a FORTRAN program to a HP BASIC program because HP BASIC does not support complex numbers However you can pass a complex number as two floating point numbers and treat them independently in the HP BASIC program 19 4 Calling System Routines The steps for calling system routines are the same as those for calling any external routine However when calling system routines you need to provide additional information which is discussed in the following sections 19 10 Using BASIC in the Common Language Environment 19 4 1 19 4 2 OpenVMS Run Time Library Routines The OpenVMS Run Time Library routines are grouped according to the types of tasks they perform The routines in each group have a prefix that identifies them as members
217. RONMENT NO JINCLUDE NO SHOW lt NOJMAP yes NO OVERRIDE ALL NONE Developing HP BASIC Programs 2 15 SHOW CDD_DEFINITIONS ENVIRONMENT INCLUDE MAP NOOVERRIDE default The SHOW qualifier determines which parts of the compilation listing are created Remarks e The size value for dynamically mapped arrays is the size of the actual array e LISTING must be specified for SHOW to be effective e CDD_DEFINITIONS controls whether the translation of a CDD Repository record is displayed in the listing e ENVIRONMENT lets you display all defaults that were in effect when the program was compiled This is the compilation listing equivalent of the SHOW command in the environment e INCLUDE controls whether files accessed with the INCLUDE directive are displayed in the listing e MAP determines whether the listing contains an allocation map The allocation map lists all program variables their size and their data type e OVERRIDE helps you debug code by disabling the effect of the NOLIST directive e NOSHOW causes the compiler to display only the source listing e SHOW ALL is the same as SHOW CDD_DEFINITIONS ENVIRONMENT INCLUDE MAP OVERRIDE e SHOW NONE is the same as NOSHOW NOJSYNCHRONOUS_EXCEPTIONS INOSYNCHRONOUS_EXCEPTIONS default The default NOSYNCHRONOUS_EXCEPTIONS qualifier allows the compiler to reorder the execution of certain arithmetic instructions to improve performan
218. ROR The OPTION statement specifies a scale factor that is not from 0 to 6 inclusive User Action Supply a valid scale factor SEQERR attempt to sequence over existing statement Explanation ERROR A SEQUENCE command specifies a starting line number that already exists in the HP BASIC source program in memory User Action Specify a starting line number higher than any existing line or delete the old statement before using the SEQUENCE command A 78 Compile Time Error Messages SEVERRSCA please submit an SPR internal error in SCA support Explanation FATAL A severe error has been detected in the SCA support in the HP BASIC compiler If you recompile your program without the ANALYSIS_DATA qualifier this error should no longer occur User Action Please submit a software problem report SPR with the source code of a small program that produces the error SEVINTERR severe internal error has been detected Submit an SPR Explanation FATAL An error has been detected in the HP BASIC compiler User Action Please submit a software problem report SPR with the source code of a small program that produces this error SHRNOTAVL Unable to access the shareable image lt name gt Explanation ERROR The shareable image is not available on your system User Action Install the correct version of the required shareable image SPANOSPA SPAN is inconsistent with NOSPAN Explanation WARNING An OPEN statement spec
219. S AS BS In this example the first line assigns the null string to variable A The second line uses the LEN function to show that the null string has a length of zero The third line uses the INPUT statement to assign a new value to A and the fourth and fifth lines print the new value and its length Declare a dynamic string LET AS PRINT LEN A INPUT AS PRINT AS PRINT LEN A END Output 0 THIS IS A TEST THIS IS A TEST 14 You should not confuse the null string with a null character A null character is one whose ASCII numeric code is zero The null string is a string whose length is zero 11 3 Using Fixed Length Strings It is generally more efficient to manipulate a fixed length string than a dynamic string Creating or modifying a dynamic string often causes HP BASIC to create new storage and this increases processor overhead String Handling 11 3 If a string variable is part of a map or common block or virtual array a LET INPUT LINPUT or INPUT LINE statement changes its value but not its length In the following example the MAP statement in the first line explicitly assigns a length to each string variable Because the LINPUT statements cannot change this length HP BASIC truncates values to fit the address and city_state variables Because the zip variable is longer than the assigned value HP BASIC left justifies the assigned value and pads it with spaces The sixth line uses the compile time con
220. S RETURN without GOSUB 73 FNEWITFUN FNEND without function call 88 ARGDONMAT Arguments don t match 89 TOOMANARG Too many arguments 97 TOOFEWARG Too few arguments 101 DATTYPERR Data type error 102 ONEOR_TWO One or two dimensions only 103 oo Internal error in BASIC Run Time Library Please submit an 104 RESNO_ERR RESUME and no error 105 REDARR Redimensioned array 116 PRIUSIFOR PRINT USING format error 122 ILLFIEVAR Illegal FIELD variable 123 STO Stop 124 MATDIMERR Matrix dimension error 126 MAXMEMEXC Maximum memory exceeded 127 SCAFACINT SCALE factor interlock 128 TAPRECNOT Tape records not ANSI continued on next page B 32 Run Time Messages Table B 1 Cont BASIC Run Time Errors Error Number Explanation 129 TAPBOTDET Tape BOT detected 130 KEYNOTCHA Key not changeable 131 NO_CURREC No current record 132 RECHASBEE Record has been deleted 133 ILLUSADEY Illegal usage for device 134 DUPKEYDET Duplicate key detected 136 ILLILLACC Illegal or illogical access 137 ILLKEYATT Illegal key attributes 138 FILIS_LOC File is locked 139 INVFILOPT Invalid file options 141 ILLOPE Illegal operation 142 ILLRECFIL Illegal record on file 143 BADRECIDE Bad record identifier 144 INVKEYREF Invalid key of reference 145 KEYSIZTOO Key size too large 146 TAPNOTANS Tape not ANSI labelled 147 RECNUMEXC RECORD number exceeds maximum 148 BADRECVAL Bad RECORDSIZE value on OPEN 149 NOTENDFIL
221. SE END IF Directive 16 4 6 DEFINE and UNDEFINE Directives 16 5 Record Dependency Relationships in CDD Repository 15 1 15 2 15 3 15 4 15 6 15 8 15 8 15 10 15 11 15 12 15 12 15 13 15 14 15 14 15 15 15 16 15 17 15 18 15 20 15 20 16 1 16 2 16 2 16 4 16 4 16 5 16 6 16 7 16 8 16 9 16 10 16 10 16 10 16 10 16 12 16 12 xi 17 Data Representation 17 1 17 1 1 17 1 2 17 1 3 17 1 4 17 2 17 2 1 17 2 2 17 2 3 17 2 4 17 2 5 17 2 6 17 3 17 4 17 4 1 17 4 2 17 5 17 6 Integer Format 4c2240 ci00 ce4cbi eebsadbiductaceised es Byte Length Integer Format 000000 00s Word Length Integer Format 0000 00 eee Longword Integer Format 0 0 cee e eens Quadword Integer Format 0 0 cece eee Real Number Format 20 000 eee SINGLE Floating Point Number Format F_floating DOUBLE Floating Point Number Format D_floating GFLOAT Floating Point Number Format G_floating SFLOAT Floating Point Number Format S_floating TFLOAT Floating Point Number Format T_floating XFLOAT Floating Point Number Format X_floating Packed Decimal Number Format 000005 String and Array Descriptor Format 005 Fixed Length String Descriptor Format Dynamic String Descriptor Format Array Descriptors s cia cess a ce en dee eee eaees eerta Creati
222. SE either explicitly names the associated handler for the protected region or marks the start of the actual handler statements The statements in the actual error handler receive control only if an error occurs in the protected region The following example prompts the user for two integer values and displays their sum The WHEN ERROR block traps any invalid input values displays a message telling the user that the input was invalid and reprompts the user for input Handling Run Time Errors 15 3 15 2 2 DECLARE INTEGER value 1 value 2 WHEN ERROR IN INPUT PLEASE INPUT 2 INTEGERS value_1 value_2 protected statement USE PRINT INVALID INPUT PLEASE TRY AGAIN handler statement RETRY thandler statement END WHEN PRINT THEIR SUM IS value_l value_2 Protected regions can be nested a protected region can be within the bounds of another protected region However WHEN ERROR statements cannot appear inside an error handler and protected regions cannot cross over into other block structures If you are using a WHEN ERROR block with a detached handler that handler cannot exist within a protected region Handlers A handler is the block of code containing instructions to be executed only when an error occurs during the execution of statements in the protected region When an error occurs during the execution of a protected region HP BASIC branches to the handler you have supplied In turn the handler processes the error An err
223. SIC tests the leftmost modifier of the same PRINT statement This condition however is not met Therefore HP BASIC executes the following PRINT statement Because both conditions are met in the third PRINT statement HP BASIC prints the value of C A 5 B 10 Cc 15 PRINT A PRINT B PRINT C END Output c 15 SA IFA 5 B UNLESS C C IFB 1 UNLESS C 15 15 IF B 10 0 UNLESS C 5 9 2 Loops Loops allow you to repeat the execution of a set of statements This set of statements is called a loop block There are three types of HP BASIC program loops FOR NEXT WHILE NEXT UNTIL NEXT Note that these types of loops can be nested that is lexically located one inside another 9 2 1 FOR NEXT Loops In a FOR NEXT loop you specify a loop control variable the loop index that determines the number of loop iterations This number must be a scalar unsubscripted variable When HP BASIC begins execution of a FOR NEXT loop the starting and ending values of the loop control variable are known Program Control 9 3 The FOR statement assigns the control variable a starting value and an ending value You can use the optional STEP clause to specify the amount to be added to the loop control variable after each loop iteration When a FOR loop block executes the HP BASIC compiler performs the following steps 1 Evaluates the starting value and assigns it to the control variable 2 Evaluates the ending
224. SMITH DEXTER 231 COLUMBUS ST 09341 TRAVIS JOHN PO BOX 80 64119 C THE CURRENT RECORD IS 3 END PROCESSING Handling Run Time Errors 15 17 15 2 7 Note that the error condition is still pending until the error handler executes the CONTINUE statement Therefore if you press Ctrl C a second time while the error handler is executing control returns to the HP BASIC error handler which terminates the program To disable Ctrl C trapping use the RCTRLC function The RCTRLC function disables only Ctrl C trapping not the Ctrl C interrupts themselves Handling Errors in Multiple Unit Programs You can use WHEN ERROR constructs anywhere in your main program or program modules Procedure and function invocations such as invocations of DEF and DEF functions and SUB FUNCTION and PICTURE subroutines as well as non BASIC programs are valid within protected regions GOTO and GOSUB statements are valid within handlers provided that the target is within the handler an outer handler or an unprotected region Note however that a detached handler cannot appear within DEF or DEF functions without the associated protected region When an error occurs within nested protected regions HP BASIC maintains the same priorities for handler use control always passes to the handler associated with the innermost protected region in which the error occurred When an exception occurs all handlers for any outer WHEN ERROR blocks are processed before the
225. See Figure 17 13 for more information Figure 17 13 Decimal Scalar String Descriptor POINTER RESERVED DIGITS SCALE ZK 5181 GE For packed decimal strings the length field contains the number of 4 bit digits not including the sign The pointer field contains the address of the first byte in the packed decimal string The scale field contains a signed power of ten multiplier to convert the internal form to the external form For example if the internal number is 123 and the scale field is 1 then the external number is 1230 Data Representation 17 11 Part Ill Using HP BASIC Features on OpenVMS Systems Part III describes BASIC features available on OpenVMS systems including advanced file input and output libraries and shareable images and error messages 18 Advanced File Input and Output This chapter describes the more advanced I O features available in HP BASIC The following topics are presented e RMS I O to ANSI magnetic tapes e Device specific I O to magnetic tapes including TK50 devices disks and unit record devices e I O to mailboxes e Network I O When you do not specify a file name in the OPEN statement the I O you perform is said to be device specific This means that read and write operations GET and PUT statements are performed directly to or from the device For example OPEN MTA2 FOR OUTPUT AS FILE 1 OPEN MTA1 PARTS DAT FOR INPUT AS FILE 2 SEQUENTIAL Because the file spe
226. Strings with DECwindows Motit arog a ene te em ae Sea RS Sa E MENS E eee Bee 22 4 xiv A Compile Time Error Messages A 1 Compile Time Errors 1 0 0 0 0 eee ees A 1 B Run Time Messages B 1 HP BASIC Run Time Errors by Mnemonic B 1 B 2 HP BASIC Run Time Errors by Number B 30 B 3 Errors Not Generated by HP BASIC 005 B 37 C Optional Programming Productivity Tools C 1 Language Sensitive Editor LSE and Source Code Analyzer SCAM ose tice Roark cin GAT Ree do de eked ae oer ae ea O E C 1 C 1 1 Preparing an SCA Library 0 00 C 2 C 1 2 Compiling From Within LSE 02005 C 2 C 1 3 HP BASIC Support for LSE and SCA Features C 3 C 2 CDD Repository lt 2 60 38 08 44 a6 ohn tiaa RRR ETRE RRR RR E t C 4 C 3 Database Management System DBMS 5 C 4 C 4 Digital Test Manager for OpenVMS 0005 C 4 C 5 Code Management System for OpenVMS CMS C 4 Index Examples 9 1 Assigning Values to Consecutive Array Elements 9 4 9 2 Assigning Consecutive Multiples to Odd Numbered Elements OF ATTA TEE T T in ce Re TE E E T EET 9 5 13 1 Creating a USEROPEN Routine 05 13 42 19 1 BASIC Main Program 0 0 00 cee eee eee 19 10 19 2 FORTRAN Subprogram 0 00 19 10 19 3 Calling System Services 0 0 00 ees 19 20 19 4 Program Displaying the QIOW System Service Ro
227. Supply an integer constant A 44 Compile Time Error Messages INTDATTYP integer data type not supported in ANSI Explanation ERROR A program compiled with the ANSI_STANDARD qualifier contains an integer variable or array User Action Remove the integer variable or array INTERR integer error or overflow Explanation WARNING The program contains an integer expression whose value is outside the valid range User Action Modify the expression so that its value is within the allowable range or use an integer data type that can contain all possible values for the expression INTERRDES please submit an SPR internal error in comment processing Explanation WARNING An error has been detected while processing a comment in the HP BASIC compiler User Action Please submit a software problem report SPR with the source code of a small program that produces the error INTERRSCA please submit an SPR internal error in SCA support Explanation ERROR An error has been detected in the SCA support in the HP BASIC compiler If you recompile your program without the ANALYSIS_DATA qualifier this error should no longer appear User Action Please submit a software problem report SPR with the source code of a small program that produces the error INVCHNNUM invalid channel number must be greater than zero Explanation ERROR A channel number less than or equal to zero was specified User Action Change the chan
228. Supply the correct device type ILLWAIVAL Illegal wait value ERR 192 Explanation The specified integer expression on the WAIT clause is less than zero or greater than 255 User Action Specify an integer expression whose value is 0 through 255 IMASQUROO Imaginary square roots ERR 54 Explanation An argument to the SQR function is negative User Action Supply arguments to the SQR function that are greater than or equal to zero IMPERRHAN improper error handling ERR 186 Explanation After an error has occurred a program s error handler calls another program unit and the called program unit executes an ON ERROR GO BACK statement before clearing the error with a RESUME statement This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Change the program logic so that the called program clears the error condition before executing the ON ERROR GO BACK statement INDNOTFUL Index not fully optimized ERR 170 Explanation A record was successfully written to an INDEXED file however the alternate key path was not optimized This slows record access User Action Delete the record and rewrite it INTERR Integer error ERR 51 Explanation The program contains an integer whose absolute value is greater than 127 in BYTE mode 32 767 in WORD mode 2 147 483 647 in LONG mode or 9 223 372 036 854 775 807 in QUAD mode User Action Use an integer in
229. T LINPUT and INPUT LINE statements receive information from a terminal format file And as the PRINT statement sends information to the terminal the PRINT statement sends information to a terminal format file Terminal format files are useful for creating files to be printed on a line printer or for supplying a program with moderate amounts of input However if you want to use the same file for both input and output you should not use terminal format files Instead use sequential relative or indexed files For more information see Chapter 13 Simple Input and Output 5 13 You do not have to use a program to create a terminal format file You can use a text editor to create a file and insert data then use a BASIC program to open the file and retrieve the data 5 3 1 Opening and Closing a Terminal Format File You use the OPEN statement to create a file or to gain access to an existing file If you do not specify either FOR INPUT or FOR OUTPUT in the OPEN statement BASIC tries to open an existing file If the file does not exist BASIC creates a new one The channel specification lets you associate a number with the file for as long as the file is open All I O operations to or from the file use this number When you are finished accessing a file you close it with the CLOSE statement 5 3 2 Writing Records to a Terminal Format File The following example receives information from a terminal then writes the informati
230. T Sail rig My boat Rig CASE P 8 6 Creating and Using Data Structures INPUT Horsepower My_boat Horsepower CASE C INPUT Length My boat Length INPUT Weight My boat Weight CASE ELSE PRINT Invalid type of boat please try again END SELECT The value of the Type_of_boat component determines the format of the variant part of the record The following example is a more complex version of the same type of procedure This program prompts for the RECORD instance components in each variant When the user responds to the Wage Class prompt the program branches to one of three CASE blocks depending on the value of Wage_class Record templates RECORD Emp wage class STRING Emp name 30 Employee name string STRING Street 15 STRING City 20 STRING State 2 DECIMAL 5 0 Zip STRING Wage class 1 These components make up the employee address field VARIANT CASE GROUP Hourly Hourly workers DECIMAL 4 2 Hourly wage Hourly wage rate SINGLE Regular_pay ytd Regular pay year to date SINGLE Overtime_pay ytd Overtime pay year to date END GROUP Hourly CASE GROUP Salaried Salaried workers DECIMAL 7 2 Yearly salary Yearly salary SINGLE Pay ytd Pay year to date END GROUP Salaried CASE GROUP Executive Executives DECIMAL 8 2 Yearly_salary Yearly salary SINGLE Pay ytd Pay year to date SINGLE Expenses_ytd Expenses year to date Creating and Using Data Struc
231. T Device type is not supported continued on next page Run Time Messages B 35 Table B 1 Cont BASIC Run Time Errors Error Number Explanation 268 269 270 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 DEVNOTOPE Device is not open DEVOUTMET Device is an output metafile DEVINMET Device is an input metafile DEVOPEING Device and operation are incompatible COONOTNDC Coordinates are not within NDC space ILLLINSTY Illegal line style number ILLLINSIZ Illegal line size ILLPOISTY Illegal point style number ILLTEXRAT Illegal text width to height ratio ILLTEXHEI Illegal text height ILLSTYIND Illegal area style index ILLCOLIND Illegal color index NUMCOOINS Number of coordinates is insufficient UNINUMNOT Unit number is not defined for the device ILLECHARE Illegal echo area ILLINIVAL Illegal initial value ENTPOINOT Entered points not within a transformation UNKGKSERR Unknown DEC GKS FOR VMS error INVCHASTR Invalid character in string STRLENZER String length is zero DATOVERF Data overflow ILLCNTCLA Illegal count clause ILLCOLMIKX Illegal color mix ILLDEVNAM Illegal device name in OPEN USEABOINP User aborted input locate point cancelled B 36 Run Time Messages B 3 Errors Not Generated by HP BASIC Table B 2 contains errors that cannot be generated in HP BASIC However they can be displayed with the ERT function and are
232. T statement immediately after a SCRATCH operation 13 6 14 Renaming Files If the security constraints permit you can change the name or directory of a file with the NAME AS statement For example NAME MONEY DAT AS ACCOUNTS DAT This statement changes the name of the file MONEY DAT to ACCOUNTS DAT Note The NAME AS statement can change only the name and directory of a file it cannot be used to change the device name You must always include an output file type because there is no default If you use the NAME AS statement on an open file the new name does not take effect until you close the file 13 30 File Input and Output 13 6 15 Closing Files and Ending I O All programs should close files before the program terminates However files are automatically closed in the following situations e At an END END PROGRAM or EXIT PROGRAM statement e When it completes the last statement in the program if no END statement exists e While executing a CHAIN statement Files are not closed after executing a STOP END SUB END FUNCTION or END PICTURE statement The CLOSE statement closes files and disassociates these files and their buffers from the channel numbers If the file is a magnetic tape device and the data is written to a tape CLOSE writes trailer labels at the end of the file The following is an example of the CLOSE statement CLOSE 1 BS 4 CLOSE 2 B 7 CLOSE I FOR I 1 TO 20 13 6 1
233. TEXT STRING CITY 30 TEXT GROUP ZIP_CODE UNSPECIFIED DECIMAL 4 0 NEW PACKED DECIMAL STRING STATE 2 TEXT DECIMAL 5 0 OLD PACKED DECIMAL END GROUP WORD EMP NUMBER SIGNED WORD STRING WAGE CLASS 2 TEXT DOUBLE SALARY YTD D FLOATING END RECORD E Using CDD Repository with BASIC 21 5 When HP BASIC translates a CDD Repository data definition it does the following e For DMU format definitions BASIC takes the field name specified in the first CDDL STRUCTURE statement and assigns that name to HP BASIC RECORD For CDO format definitions BASIC takes the record name from the CDO DEFINE RECORD statement and assigns that name to a HP BASIC RECORD In the previous example the first CDD Repository structure statement is employee structure When HP BASIC translates this line of a CDD Repository data definition it names the record EMPLOYEE If this first structure is unnamed HP BASIC signals the error Record from CDD Repository does not have a record name e Translates the field name in any subsequent CDD Repository STRUCTURE statement to be the name of a group In the previous example the second STRUCTURE statement zip_code structure is translated to GROUP ZIP_ CODE e Translates subordinate field names in CDD Repository STRUCTURE statements to elementary components in the RECORD statement In the previous example the subordinate field name street is translated to STRING STREET If you specify
234. TYPE clause lets you specify record formats that are compatible with files created by other language processors You can choose one of four qualifiers LIST FORTRAN ANY and NONE The default for BASIC is LIST which specifies carriage return format This is standard for ASCII text files and means that carriage control is performed by RMS when writing the file to a unit record device If your program accesses a file created with a Fortran language processor use the FORTRAN qualifier In the following example the FORTRAN qualifier sets the FORTRAN carriage control attribute in the RAT field in the FAB For more information about the FAB control structure see Section 13 8 11 The first byte of the record is assumed to be the carriage control information For example OPEN FIL DAT FOR INPUT AS FILE 1 amp ORGANIZATION SEQUENTIAL RECORDTYPE FORTRAN If your program accesses a file created by an unknown language processor or by DCL use the ANY qualifier this qualifier causes BASIC to handle any record attribute type If you create a file with the ANY qualifier BASIC uses the default of LIST For example OPEN FIL DAT FOR INPUT AS FILE 1 amp ORGANIZATION INDEXED RECORDTYPE ANY File Input and Output 13 39 13 8 10 TEMPORARY Clause If you specify the TEMPORARY clause in the OPEN statement BASIC deletes that file in any one of the following cases e When you close the file e When the program aborts or exits e When your pr
235. UDIT 2 6 CDD Repository 21 1 to 21 30 CHECK 2 6 cross reference listing 2 7 CROSS_REFERENCE 2 7 DEBUG 2 7 DECIMAL_SIZE 2 8 DEPENDENCY_DATA 2 8 21 7 DIAGNOSTICS 2 8 FLAG 2 9 JINTEGER_SIZE 2 9 line numbers 3 3 LINES 2 10 Index 1 BASIC cont d LISTING 2 10 2 21 MACHINE_CODE 2 10 OBJECT 2 11 OLD_VERSION CDD_ARRAYS 21 13 OPTIMIZE 2 12 overview 1 1 to 1 2 producing source listing file 2 10 REAL_SIZE 2 14 ROUND_DECIMAL 2 14 SCALE 2 15 SEPARATE_COMPILATION 2 15 SHOW 2 16 SYNCHRONOUS_EXCEPTIONS 2 16 TYPE_DEFAULT 2 17 VARIANT 2 17 16 10 WARNINGS 2 18 BASIC character set 4 5 BASIC command 2 1 BASIC command qualifiers list of 2 3 BASIC compiler functions of 2 1 BASIC concepts 4 1 to 4 14 BASIC elements 4 1 to 4 14 BASIC programs developing 2 1 to 2 31 Bindings 22 1 Exceptions 22 2 to 22 3 Block loop 9 38 Block size specifying 18 2 BLOCKSIZE with the MOUNT command 18 2 Bounds array 4 11 CDD Repository arrays 2 11 Breakpoint 3 7 BRIEF 2 23 BUCKETSIZE 13 34 default value 13 35 Buffers T O 13 6 record 13 6 Index 2 Built in lexical functions VARIANT directive 16 10 BY DESC 19 2 BY REF 19 2 BYTE data type 4 7 subtypes 4 7 BY VALUE 19 2 C Call stack 3 6 CALL statement 12 8 19 7 implicit declarations in 12 9 parameters in 12 8 using for FUNCTION subprograms 12 9 CASE in RECORD variants 8 5 CAS
236. UND functions These functions can be used only with arrays that have been previously declared 6 5 Assigning and Displaying Array Values The following sections explain how to access and write to BASIC arrays with the LET and PRINT statements 6 5 1 Assigning Values with the LET Statement The LET statement assigns values to individual array elements For example DIM voucher_num 100 LET voucher_num 20 3253 END You can also assign values to a portion of an array with the LET statement and a FOR NEXT loop In the following example the FOR NEXT loop assigns zero to array elements 1 5 to 1 10 2 5 to 2 10 and 3 5 to 3 10 Arrays 6 9 DIM po_number 100 100 FOR I 1 TO 3 FOR J 5 TO 10 LET po number I J 0 NEXT J NEXT I END 6 5 2 Listing Array Elements with the PRINT Statement You print individual array elements by naming those elements in the PRINT statement For example PRINT parts list 35 With a FOR NEXT loop you can print all or part of an array For example DIM capture _ratio 10 10 FOR Y 7 TO 10 FOR X 7 TO 10 PRINT capture ratio X Y NEXT X g NEXT Y 6 6 Using MAT Statements Note The MAT statements discussed in this section are not related to the MAT GRAPH and MAT PLOT graphics statements For more information about these statements see Programming with VAX BASIC Graphics MAT statements let you assign values to or disp
237. US 2 you must remove the incompatible language feature LANFEAOPEI language feature not available in BASIC Explanation ERROR The program contains a PRINT statement with a RECORD clause BASIC does not support the RECORD clause in PRINT statements User Action Remove the RECORD clause LEFBOUSPE left boundary must be less than the right boundary Explanation ERROR In a statement that specifies a viewport or windowsize you specified a left boundary that is greater than or equal to the corresponding right boundary User Action Correct the left boundary so that it is less than the right boundary LENDYNSTR string length not allowed on dynamic string lt name gt Explanation ERROR The program contains a dynamic string variable declaration that specifies a string length User Action Length specifications are allowed only for fixed length strings remove the length specification from the dynamic string or allocate the string in a MAP or COMMON LENNUMFIL string length not allowed on numeric FILL Explanation ERROR The program contains a numeric FILL item that specifies a length User Action Remove the length specification from the numeric FILL item Compile Time Error Messages A 51 LETDIRSYN LET directive syntax error Explanation ERROR A LET directive contains a syntax error for example an invalid lexical identifier User Action Use the correct syntax for the LET directive LETKEYREQ LET ke
238. X Y point specification between them User Action Either supply another point or remove the extra semicolon Compile Time Error Messages A 91 Run Time Messages HP BASIC returns run time messages if an error occurs while a program is executing The error is diagnosed and for programs without line numbers HP BASIC indicates the program line that generated the error Warning messages indicate that an error has occurred but program execution continues In some cases HP BASIC performs the specified operation but the results are not as expected Fatal severe error messages indicate that the program has aborted You can recover from most fatal errors by including error handling routines in your program and by specifying OPTION HANDLE SEVERE Certain errors however are not recoverable even when error handlers are used In the descriptions of these errors they are designated as not able to be trapped You do not need error handling routines to trap errors that generate warning messages Section B 1 lists HP BASIC run time errors alphabetized by mnemonic code Section B 2 is a cross reference numerical listing of run time errors generated by HP BASIC Section B 3 lists messages that HP BASIC does not generate but which can be displayed with the ERT function See the HP BASIC for OpenVMS Reference Manual for information about RMSSTATUS and VMSSTATUS B 1 HP BASIC Run Time Errors by Mnemonic The HP BASIC error message format is as f
239. XT SHOULD PRINT AT LEFT MARGIN ABCDE ABCDEFG ABCDEFGHI YOU ONLY SEE PART YOU CAN SEE ALL OF THE LINE WHEN IT IS EXTENDED 14 5 PRINT USING Statement Error Conditions There are two types of PRINT USING error conditions fatal and warning BASIC signals a fatal error if e The format string is not a valid string expression e There are no valid fields in the format string e You specify a string for a numeric field e You specify a number for a string field e You separate the items to be printed with characters other than commas or semicolons 14 16 Formatting Output with the PRINT USING Statement e A format field contains an invalid combination of characters e You print a negative number in a floating dollar sign or asterisk fill field without a trailing minus sign BASIC issues a warning if a number does not fit in the field If a number is larger than the field allows BASIC prints a percent sign followed by the number in the standard PRINT format and continues execution If a string is larger than any field other than an extended field BASIC truncates the string and does not print the excess characters If a field contains an invalid combination of characters BASIC does not recognize the first invalid character or any character to its right as part of the field These characters might form another valid field or be considered text If the invalid characters form a new valid field a fatal error condition might arise if
240. XYZ 7 7 3 FILL Items FILL items reserve space in map and common blocks and in record buffers accessed by MOVE or REMAP statements Thus FILL items mask parts of the record buffer and let you skip over fields and reserve space in or between data elements Data Definition 7 9 FILL formats are available for all data types Table 7 1 summarizes the FILL formats and their default allocations if no data type is specified Table 7 1 FILL Item Formats Representations and Default Allocations FILL Format Representation Bytes Used FILL Floating point 4 8 16 or 32 FILL n n floating point elements 4n 8n 16n or 32n FILL Integer BYTE WORD LONG or QUAD 1 2 4 or 8 FILL n n integer elements 1n 2n 4n or 8n FILL String 16 FILL n n string elements 16n FILL m String m FILL n m n string elements m bytes each m n Note In the applicable formats of FILL n represents a repeat count not an array subscript FILL n for example represents n real elements not n l You can also use data type keywords with FILL and optional data type suffixes The data type and storage requirements are those of the last data type specified For example MAP QED STRING A FILL 24 LONG SSN FILL REAL SAL FILL 5 This MAP statement uses data type keywords to reserve space for e A 16 character string variable A e 24 bytes of padding e One LONG variable SSN e 4 bytes of padding e One REAL variable SAL e Spac
241. Y reexecutes the NEXT statement In UNTIL NEXT and WHILE NEXT loops if the error occurs while HP BASIC is evaluating the relational expression RETRY reexecutes the NEXT statement CONTINUE Statement You can use the CONTINUE statement to clear the error and cause execution to continue at the statement immediately following the propagated error When the CONTINUE statement is within an attached handler you can specify a target The target can be a line number or label within the bounds of the associated protected region in a surrounding protected region or within an unprotected region however you must specify a target within the current program module You cannot specify a target for the CONTINUE statement when it is in a detached handler For example 15 8 Handling Run Time Errors DIM LONG her attributes 10 his attributes 10 DECLARE INTEGER counter E WHEN ERROR USE fix it DATA 12 2 35 21 25 5 32 32 30 15 4 FOR counter 0 TO 12 READ her attributes counter NEXT counter MAT his attributes her attributes END WHEN HANDLER fix it Trap out of data IF ERR 57 THEN RESTORE CONTINUE ELSE EXIT HANDLER END IF END HANDLER When a DEF function is invoked from a protected region and an error occurs that has not been handled a CONTINUE statement with no target causes execution to resume at the statement following the one that invoked the function Note that if an error occurs in a loop control statement or SELECT or
242. a point where an explicit breakpoint is set e STEP at a RESUME statement in an ON ERROR handler results in the program execution stopping at the first line of non error handler code e Use SET BREAK EXCEPTION at the beginning of the debugging session to prevent unexpected errors from occurring This breakpoint is not necessary if you have set explicit breakpoints at all error handlers However use of this command will break at all exceptions allowing you to check that you have the proper breakpoints to stop program execution following the exception 3 18 Using the OpenVMS Debugger with BASIC Part Il HP BASIC Programming Concepts Part II explains HP BASIC programming concepts including input and output arrays data definition program control and functions 4 BASIC Concepts and Elements A BASIC program is a series of instructions for the compiler These instructions are built using the fundamental elements of BASIC This chapter describes these elements or building blocks 4 1 Line Numbers BASIC gives you the option of developing programs with line numbers or without line numbers 4 1 1 Programs with Line Numbers If you use line numbers in your program you must follow these rules e A line number must be a unique integer from 1 to 32767 HP BASIC does not allow programs to have duplicate line numbers e A line number can contain leading zeros however embedded spaces tabs and commas are invalid in line numbers
243. a question mark SET PROMPT INPUT Please enter your name Employee_name Output Please enter your name The SET NO PROMPT statement is valid for INPUT LINPUT INPUT LINE and MAT INPUT statements If the prompt is disabled any one of the following commands reenables it e The SET PROMPT statement e The CHAIN statement e The NEW OLD RUN or SCRATCH compiler command 5 1 2 Providing Input from the Source Program The following sections describe the READ DATA and RESTORE statements To use READ and DATA statements you must know what data is required when writing the program These statements do not stop to request data while the program runs therefore your program runs faster than with the INPUT statements The RESTORE statement lets you use the same data items more than once Simple Input and Output 5 5 5 1 2 1 READ and DATA Statements The READ statement reads values from a data block A data pointer keeps track of the data read Each time the READ statement requests data BASIC retrieves the next available constant from a DATA statement The DATA statement contains the values that the READ statement reads In a DATA statement integer constants are whole numbers they cannot be followed by a percent sign In the following example BASIC signals an error because the integer constants in the DATA statement contain percent signs 10 WHEN ERROR USE catch it DATA 1 2 3 20 READ A BS C END WHEN 400 HANDLER
244. a type User Action Remove the operation or change the data type of the arguments ILLOPTBAS illegal OPTION BASE value Explanation INFORMATION A program compiled with the ANSI_ STANDARD qualifier contains an OPTION BASE statement that specifies a value other than 0 or 1 User Action Change the OPTION BASE statement to specify either 0 or 1 ILLQUACOM illegal qualifier combination Explanation ERROR In the VAX BASIC Environment you specified an illegal combination of qualifiers such as COMPILE NOSHOW CDD User Action Issue the command again using a valid combination of qualifiers ILLSTROPE illegal string operator Explanation ERROR The program specifies an invalid string operation for example A B C User Action Replace the invalid operator ILLUSAFIE illegal usage of FIELDed variable Explanation ERROR A MAT statement operates on an element of a string array that appears in a FIELD statement User Action Remove the array from the MAT statement ILLUSEUNA illegal use of unary operator Explanation ERROR A compiler directive contains an invalid lexical expression for example IF 1 NOT 2 User Action Correct the invalid lexical expression ILLWAIVAL WAIT value must be in the range 0 to 255 inclusive Explanation ERROR An integer expression was specified on a WAIT clause that is less than 0 or greater than 255 User Action Specify an integer expression from 0 to 255 C
245. a type keyword for the variable or compile the program without the TYPE EXPLICIT qualifier DATTYPNOT data type keyword not allowed in SUB statement Explanation ERROR A SUB statement contains a data type keyword between the subprogram name and the parameter list User Action Remove the data type keyword In a SUB statement data type keywords can appear only within the parameter list DATTYPREQ data type required in EXTERNAL CONSTANT declaration Explanation ERROR An EXTERNAL CONSTANT statement has no data type keyword User Action Supply a data type keyword to specify the data type of the external constant DECIMERR DECIMAL overflow Explanation WARNING The program contains a DECIMAL expression whose value is outside the valid range User Action Reduce the value of the DECIMAL expression DECLEXSYN DECLARED lexical function syntax error Explanation ERROR The syntax of the DECLARED lexical function is specified incorrectly User Action Supply the correct syntax A 20 Compile Time Error Messages DECPREOUT DECIMAL precision specification out of range Explanation ERROR In the declaration for a packed decimal variable or constant the number of digits to the right of the decimal point is greater than the total number of digits specified or greater than 31 User Action Change the declaration so that the total number of digits specified is less than 31 and the number of digits to the right of the
246. able the value is converted to a floating point number 4 7 2 Integer Variables An integer variable is a named location that stores a whole number The storage space required to hold the value depends on the variable s INTEGER subtype For example each BYTE integer variable requires 8 bits 1 byte of storage while each LONG integer variable requires 32 bits 4 bytes of storage If you assign a floating point value to an integer variable the fractional portion of the value is trunctated it does not round to the nearest integer In the following example the value 5 not 6 is assigned to the integer variable B 5 7 Although the integer data types QUAD LONG WORD and BYTE allow the minimum values 9223372036854775808 2147483648 32768 and 128 respectively you cannot use these constants explicitly because HP BASIC reports an integer overflow error while attempting to parse the literal constant To use these values you must use either radix notation such as 32768 L or a constant expression For example 4 10 BASIC Concepts and Elements DECLARE WORD CONSTANT Word_const 32767 1 4 7 3 Packed Decimal Variables A packed decimal DECIMAL data type variable is made up of several storage locations the number of which depends on the declared size of the variable However a packed decimal variable is still referred to by a single variable name When you declare a packed decimal variable you specify th
247. ables except those in MAP or COMMON statements are initialized to zero or the null string each time the subprogram is called e Arrays created with an executable DIMENSION statement The array is reinitialized each time the array is redimensioned 4 12 BASIC Concepts and Elements 4 8 Keywords and Reserved Words Keywords are elements of the BASIC language Keywords that are not reserved can be used as user identifiers such as labels variable or constant names or names of MAP or COMMON areas Depending upon the location of the keyword in your program statement the compiler will treat it as either a keyword or a user identifier Your programs use keywords and reserved words to e Define data e Perform operations e Invoke functions See the HP BASIC for OpenVMS Reference Manual for a list of keywords and reserved words Keywords determine whether the statement is executable or nonexecutable Executable statements such as PRINT GOTO and READ perform operations Nonexecutable statements such as DATA DECLARE and REM describe the characteristics and arrangement of data usage information and comments Every statement except LET must begin with a keyword A keyword cannot have embedded spaces or be split across lines of text There must be a space or tab between the keyword and any other variables or operators There are also phrases of keywords In this case the spacing requirements vary 4 9 Operands Operators and Expressions
248. ached handler for the second WHEN ERROR block traps timeout errors and deadlock errors If the desired information does not become available in the specified amount of time or a deadlock condition occurs the employee s badge number is printed out with an appropriate message and the GET statement tries to retrieve the next record in the sequence 13 6 10 Accessing Records by Record File Address A Record File Address RFA uniquely specifies a record in a file Accessing records by RFA is therefore more efficient and faster than other forms of random record access 1 Because an RFA requires six bytes of storage BASIC has a special data type RFA that denotes variables that contain RFA information Variables of data type RFA can be used only with the I O statements and functions that use RFA information and in comparison and assignment statements You cannot print these variables or use them in any arithmetic operation However you can compare RFA variables using the equal to and not equal to lt gt relational operators You cannot create named constants of the RFA data type However you can assign values from one RFA variable to another and you can use RFA variables as parameters Accessing a record by RFA requires the following steps 1 Explicitly declare the variable or array of data type RFA to hold the address 1 Record File Addresses do not exist for terminal format files File Input and Output 13 27 2 Assi
249. acter If you specify a channel that is not open HP BASIC signals the error I O channel not open ERR 9 If a file or a device other than a terminal is open on the channel HP BASIC signals the error Illegal operation ERR 141 Once you have specified a channel HP BASIC allows you to specify an optional WAIT clause A WAIT clause followed by no value tells HP BASIC to wait indefinitely for input to become available A WAIT clause followed by a value from 1 to 255 tells HP BASIC to wait the specified number of seconds for input DECLARE STRING KEYSTROKE Inkey Loop WHILE 1 KEYSTROKE INKEY 1 WAIT SELECT KEYSTROKE CASE 26 C PRINT Ctrl Z to exit EXIT Inkey Loop CASE CR LF VT FF ESC PRINT Line terminator CASE PF1 TO PF4 PRINT P key CASE El TO E6 PRINT VT200 Function key CASE KPO TO KP9 PRINT Application keypad key CASE lt SP PRINT Control character CASE 127 C PRINT lt DEL gt CASE ELSE PRINT Character is KEYSTROKE END SELECT NEXT Functions 10 17 10 2 User Defined Functions 10 2 1 The DEF statement lets you create your own single line or multiline functions In HP BASIC a function name consists of the following e The letters FN e From 1 to 28 letters digits underscores or periods e An optional percent sign or dollar sign Integer function names must end with a percent sign and string function names must end with a dollar sign therefore the function nam
250. ageable routines and modules In a segmented or modular program each routine or module usually performs only one logical function You can therefore design and implement a modular program faster than a nonsegmented program Program modularity also simplifies debugging and testing as well as program maintenance and transportability Subprograms processed by the HP BASIC compiler conform to the OpenVMS Procedure Calling Standard This standard prescribes how arguments are passed how values are returned and how procedures receive and return control Because HP BASIC conforms to the OpenVMS Procedure Calling Standard an HP BASIC subprogram or main program can call or be called by any procedure written in a language that also conforms to this standard For information about calling non BASIC procedures see Chapter 19 12 1 HP BASIC Subprograms HP BASIC has SUB and FUNCTION subprograms Each of these subprograms receives parameters and can modify parameters passed by reference or by descriptor The differences between SUB and FUNCTION subprograms are as follows e FUNCTION subprograms must be declared with an EXTERNAL statement in the calling program Declaring SUB subprograms is optional e FUNCTION subprograms return a value SUB subprograms do not return a value All subprograms invoked by an HP BASIC program must have unique names A HP BASIC program cannot have different subprograms with the same identifiers Program Segmentation 1
251. aining a comma you should enclose the string in quotation marks or use the INPUT LINE or LINPUT statement If you do not BASIC treats the comma as a delimiter and assigns only part of the string to the variable If you use quotation marks be sure to type both beginning and ending marks If you leave out the end quotation mark BASIC signals Data format error ERR 50 5 1 1 2 INPUT LINE and LINPUT Statements The INPUT LINE and LINPUT statements prompt you for string data while your program runs You can respond with strings that contain commas semicolons and quotation marks which are characters that the INPUT statement interprets as delimiters The INPUT LINE statement accepts and stores all characters including quotation marks semicolons and commas up to and including the line terminator or terminators LINPUT accepts all characters up to but not including the line terminator or terminators Simple Input and Output 5 3 In the following example because both INPUT LINE and LINPUT treat your input as a string literal BASIC interprets quotation marks commas and semicolons as characters not as string delimiters When A is input with the INPUT LINE statement the carriage return line terminator is stored as part of the string The first PRINT statement tells BASIC to print all three variables on one line starting each one in a new print zone However when BASIC prints the three strings it prints the carriage return charact
252. akes precision as follows The sum or difference of the integer parts takes the precision of the larger part The sum or difference of the decimal fraction parts takes the precision of the more precise part e Trailing zeros are trunctated QUO PLACE and PROD Functions In the QUO PLACE and PROD functions the value of the integer expression argument explicitly determines numeric precision That is the integer expression parameter determines the point at which the number is rounded or truncated If the integer expression is between 5000 and 5000 rounding occurs according to the following rules e For positive integer expressions rounding occurs to the right of the decimal point For example if the integer expression is 1 rounding occurs one digit to the right of the decimal point the number is rounded to the nearest tenth If the integer expression is 2 rounding occurs two digits to the right of the decimal point the number is rounded to the nearest hundredth and so on e For zero rounding occurs to the nearest unit e For negative integer expressions rounding occurs to the left of the decimal point For example if the integer expression is 1 rounding occurs one place to the left of the decimal point In this case HP BASIC moves the decimal point one place to the left then rounds to units If the integer expression is 2 rounding occurs two places to the left of the decimal point Functions 10 11
253. akes programs run faster However using OPTIMIZE produces extra instructions to perform the optimization which might result in larger object modules and longer compile times than the NOOPTIMIZE qualifier e To speed compilations during program development compile with NOOBJECT qualifier to check syntax with NOOPTIMIZE to check for correct execution and finally with OPTIMIZE for the final check SINGLE DOUBLE GFLOAT SFLOAT TFLOAT XFLOAT REAL_SIZE REAL_SIZE SFLOAT 164 default SINGLE Alpha default The REAL_SIZE qualifier specifies the default size for floating point data Remarks e The default floating point size applies to all floating point variables whose size is not explicitly declared See the HP BASIC for OpenVMS Reference Manual for more information about floating point data types NOJROUND_DECIMAL NOROUND_DECIMAL default The ROUND_DECIMAL qualifier causes the compiler to round packed decimal numbers rather than truncate them The NOROUND_DECIMAL qualifier causes the compiler to truncate packed decimal numbers rather than round them The ROUND_DECIMAL qualifier causes the INTEGER function to round rather than truncate the decimal part SCALE n 2 14 Developing HP BASIC Programs SCALE 0 default The SCALE qualifier specifies a scale factor from zero to six inclusive The scale factor affects only double precision numbers The SCALE qualifier helps to control accumulated round
254. am that is not a HP BASIC error or does not map onto a HP BASIC error it is signaled as NOTBASIC Not a BASIC error ERR 194 In this case you can use the built in function VMSSTATUS to determine what caused the error Determining the Error Number ERR You use the ERR function to return the number of the last error that occurred Appendix B lists the number of each HP BASIC run time error for example ERR 153 is RECALREXI Record already exists OPTION HANDLE ERROR WHEN ERROR USE find error END WHEN HANDLER find error SELECT ERR Record already exists CASE 153 PRINT Choose new record CONTINUE CASE ELSE EXIT HANDLER END SELECT END HANDLER The results of ERR remain undefined until an error occurs Although ERR remains defined as the number of the last error after control leaves the error handler it is poor programming practice to refer to this variable outside the scope of an error handler 15 12 Handling Run Time Errors 15 2 5 2 Determining the Error Line Number ERL After your program generates an error the ERL function returns the BASIC line number of the signaled error This function is valid only in line numbered programs The ERL function like ERR lets you set up branching to one of several paths in the code In the following example the handler continues execution at different points in the program depending on the value of ERL 10 DECLARE INTEGER CONSTANT TRUE 1 20 WHEN ERROR US
255. ame for basic is salary end info structure end city study Translated RECORD Statement 1 INCLUDE FROM CDD CDDSTOP BASIC CITY STUDY BYTE SALARY SIGNED BYTE END RECORD Cl This example formats data resulting from a Cl study on the relationship between place of birth Cl and earning potential Cl RECORD INFO UNSPECIFIED Cl STRING SUBJECT NAMES 10 TEXT Cl STRING CITY OF BIRTHS 10 TEXT C C Caution The NAME FOR BASIC clause enables you to assign completely different names to the same field For more information about the CDDL NAME FOR BASIC field attribute clause see the CDD Repository documentation 21 9 CDD Repository Data Types HP BASIC supports a subset of CDD Repository data types as shown in Table 21 1 21 16 Using CDD Repository with BASIC Table 21 1 Supported CDD Repository Data Types Data Type HP BASIC Translation TEXT STRING SIGNED BYTE BYTE SIGNED WORD WORD SIGNED LONGWORD LONG F_FLOATING SINGLE D_FLOATING DOUBLE G_FLOATING GFLOAT PACKED DECIMAL DECIMAL If a CDD Repository data definition containing an unsupported data type is extracted HP BASIC signals the informational message Datatype in CDD Repository not supported substituted group for lt field name gt and translates the data type by creating a group to contain the data type field The group name is the name of the unsupported data type followed by the text VALUE This allows
256. ame within RECORD instance Single_test the element of array Group_2 must be specified In this case the extra components must be specified because each element of GROUP Group_2 contains a component named Group_2_decimal Array of test i Group_2 j Group 2 decimal Single test Group_2 j Group 2 decimal You can assign all the values from one RECORD instance to another RECORD instance as long as the RECORD instances are identical except for names In the following example RECORD instances First_test1 Second_test1 and the individual elements of array Array_of_test1 have the same form an array of four groups each of which contains a 10 byte string variable followed by a REAL variable followed by an INTEGER variable Any of these RECORD instances can be assigned to one another RECORD Templates RECORD Testl GROUP Group_1 4 STRING My string 1 10 REAL My real 1 INTEGER My integer 1 Creating and Using Data Structures 8 11 END GROUP END RECORD RECORD Test2 GROUP Group_2 STRING My string 2 10 REAL My real 2 INTEGER My integer 2 END GROUP END RECORD RECORD Test3 STRING My string 3 10 REAL My real 3 INTEGER My integer 3 END RECORD Declarations DECLARE Test1 First_testl amp Second testl amp Array of test1 3 DECLARE Test2 First_test2 DECLARE Test3 First_test3 amp Array of test3 10 Program logic starts here A single RECORD instance is assigned to another single instance First_testl
257. an upper bound of 5 0 1 LEVEL 2 2 3 4 default GENERIC default HOST EV4 EV5 werd B h EV6 EV67 ITANIUM2 MERCED NOJOPTIMIZE OPTIMIZE LEVEL 4 default OPTIMIZE TUNE GENERIC default The OPTIMIZE qualifier causes the compiler to optimize the program to generate more efficient code for optimum run time performance Specifying NOOPTIMIZE causes the compiler to perform minimal optimizations The following list describes the OPTIMIZE LEVEL options e 0 has the same effect as NOOPTIMIZE Most optimizations are turned off e 1has some optimizations such as instruction scheduling 2 12 Developing HP BASIC Programs 2 adds more optimizations such as loop unrolling and split lifetime analysis to those in level 1 3 adds more optimizations 4 is the default level OPTIMIZE LEVEL 4 is equivalent to OPTIMIZE or not specifying the qualifier Level 4 is the maximum optimization level The OPTIMIZE TUNE qualifier selects processor specific instruction tuning for a specific implementation of the Itanium or Alpha architecture Tuning for a specific implementation can provide improvements in run time performance Regardless of the setting of the OPTIMIZE TUNE qualifier the generated code will run correctly on all implementations of the Itanium or Alpha architecture as appropriate Note that code tuned for a specific target might run more slowly on another target than generically tuned
258. and User Action Enter the HP BASIC command correctly Compile Time Error Messages A 87 UNLINCREA UNLOCK EXPLICIT clause inconsistent with ACCESS READ Explanation ERROR An OPEN statement contains both an ACCESS READ and an UNLOCK EXPLICIT clause This is inconsistent because ACCESS READ specifies no record locking while UNLOCK EXPLICIT specifies that all accessed records remain locked until explicitly unlocked User Action Either remove the UNLOCK EXPLICIT clause or change the ACCESS clause UNREACH code can never be executed at label lt label gt Explanation INFORMATION The compiler has detected code that will never be executed for example a multistatement line whose first statement is a GOTO EXIT ITERATE RESUME or RETURN Alpha BASIC only User Action Review the program to determine if the code should be executed If you determine the code should be executed then you should revise the program flow logic accordingly otherwise the code is unnecessary and you may want to remove it In the case of the GOTO EXIT ITERATE RESUME or RETURN statements make sure that these statements are the only statements on the line or the last statement on a multistatement line UNSCDDLEV unsupported CDD Repository level lt number gt Supported level is lt number gt Explanation ERROR The current CDD Repository version is incompatible with HP BASIC User Action Use a supported version of CDD Repository UNTSTRLIT
259. annot locate the definition for a specified global symbol reference For example a main program module OCEAN OBJ calls the subprograms located in object modules REEF OBJ SHELLS OBJ and SEAWEED OBJ However the following LINK command does not reference the object module SEAWEED OBJ LINK OCEAN REEF SHELLS This example produces the following error messages SLINK W NUDFSYMS 1 undefined symbol SLINK I UDFSYMS SEAWEED SLINK W USEUNDEF module OCEAN references undefined symbol SEAWEED LINK W DIAGISUED completed but with diagnostics If an error occurs when you link modules you can often correct the error by reentering the command string and specifying the correct modules or libraries See the OpenVMS System Messages and Recovery Procedures Reference Manual for a complete list of linker messages Developing HP BASIC Programs 2 27 2 3 Running an HP BASIC Program After you link your program use the DCL command RUN to execute it The RUN command has the following format RUN NO DEBUG file spec NO DEBUG NO DEBUG The NO DEBUG qualifier is optional Specify the DEBUG qualifier to request the debugger if the image is not linked with it You cannot use DEBUG on images linked with the NOTRACEBACK qualifier If the image is linked with the DEBUG qualifier and you do not want the debugger to prompt use the NODEBUG qualifier The default action depends on whether the file is linked with the DEBUG qualifier
260. applications on each window To program in the DECwindows Motif environment DECwindows Motif bindings are used to help write programs that create and manage the different resources needed to control the windowing environment 22 2 Using DECwindows Motif Bindings with BASIC The DECwindows Motif bindings consist of constant definitions global variable declarations record structures and function prototypes The bindings include everything that is needed to do windows programming using the DECwindows Motif Application Programming Interface API The BASIC implementation of the DECwindows Motif bindings allow you to write to either the C version or the non C version of the bindings In either case you will want to refer to the VMS DECwindows User Interface Language Reference Manual before you start programming For information about using non C bindings see the DECwindows Motif for OpenVMS Guide to Non C Bindings BASIC HELLOMOTIF BAS and BASIC HELLOBURGER BAS supplied on the kit as examples of using the BASIC language for windows programming Using DECwindows Motif Bindings with BASIC 22 1 A BASIC user can code to the standard C DECwindows Motif bindings with the following exceptions e Any identifiers longer than 31 characters must be truncated to 31 characters Known instances include S__XmTraverseObscuredCallbackStru 33 S_XmOperationChangedCallbackStruc 33 S_XmDragDropFinishCallbackStruct 32 e Any identifiers beginnin
261. arameter DEADLOCK_WAIT the system correctly specifies that a deadlock situation has occurred The following example uses the WAIT clause to overcome a record locked condition and traps the resulting error condition MAP worker STRING first name 10 amp last name 20 amp badge number 6 amp LONG dept_number MAP departments STRING dept_name 10 amp LONG dept code OPEN Employee data dat FOR INPUT AS FILE 1 amp INDEXED FIXED MAP worker ACCESS MODIFY amp PRIMARY badge_number OPEN departments dat FOR INPUT AS FILE 2 amp INDEXED FIXED MAP departments ACCESS MODIFY amp PRIMARY dept_code WHEN ERROR IN WHILE 1 GET 1 WAIT WHEN ERROR USE time expired handler GET 2 KEY 0 EQ dept number amp WAIT 10 END WHEN PRINT badge number dept name NEXT USE SELECT ERR CASE 11 PRINT End of file reached CLOSE 1 2 CASE 193 PRINT Deadlock detected UNLOCK 2 RETRY CASE ELSE EXIT HANDLER END SELECT END WHEN 13 26 File Input and Output HANDLER time expired handler IF ERR 15 OR ERR 193 THEN PRINT Department info not available for PRINT Employee badge number PRINT Going on to next record CONTINUE ELSE EXIT HANDLER END IF END HANDLER END PROGRAM The first WHEN ERROR block traps any deadlock conditions The WHEN ERROR handler unlocks the current record on channel 2 in case another program is trying to access it and then retries the operation The det
262. ariable HP BASIC built in function or user defined function In HP BASIC the function definition can contain a reference to the function you are defining Therefore a multiline DEF function can be recursive or invoke itself however HP BASIC does not detect infinitely recursive DEF functions during compilation If your program invokes an infinitely recursive DEF function HP BASIC will eventually signal a fatal run time error typically the error Access violation You can use either the END DEF or EXIT DEF statements to exit from a user defined function The EXIT DEF statement is equivalent to an unconditional transfer to the END DEF statement The following example shows a multiline DEF function that uses both the EXIT and END DEF statements The defining expression of the function is in the ELSE clause This assigns a value to the function if A is less than 10 The second set of output shows what happens when A is greater than 10 HP BASIC prints OUT OF RANGE and executes the EXIT DEF statement The function returns zero because control is transferred to the END DEF statement before a value was assigned In this way this example tests the arguments before the function is evaluated 10 20 Functions DEF fn discount A IF A gt 10 THEN PRINT OUT OF RANGE EXIT DEF ELSE fn discount A A END IF END DEF INPUT Z PRINT fn_discount Z END Output 1 4 256 Output 2 12 OUT OF RANGE 0 If you do not explic
263. ariable required Explanation ERROR A nonnumeric variable was found with a numeric data type User Action Specify a numeric variable OBJFAIL failure in loading object file Explanation FATAL In the VAX BASIC Environment either an attempt was made to load a non BASIC object module or the compiler could not find the object file referenced by a CALL statement or EXTERNAL FUNCTION reference User Action If the object file resides in the Common Run Time Library you must link the program at DCL level If the object file is in a user supplied library use the DCL LIBRARY command to install the missing object module You can load only VAX BASIC object modules ONENOTWHE ON ERROR not allowed in WHEN block or handler Explanation ERROR An ON ERROR statement has been found in a WHEN block or an associated error handler User Action Remove the ON ERROR statement from the WHEN block or associated error handler OPEEXPNOT operator expected not found Explanation ERROR A compiler directive contains an invalid lexical expression that has a right parenthesis immediately followed by a lexical identifier User Action Correct the lexical expression OPEMUSFOL operator must follow right parenthesis Explanation ERROR The program contains an incorrect lexical expression User Action Correct the lexical expression Compile Time Error Messages A 65 OPENIN error opening lt file name gt as input Explanation ERR
264. ary routine LIB LOOKUP_KEY declared in Section 19 2 2 When the routine LIB LOOKUP_KEY is called it is invoked as a function The first two parameters are required all remaining parameters are optional LONG FUNCTION LIBSLOOKUP_KEY STRING LONG OPTIONAL LONG STRING INTEGER ret_status LIBSLOOKUP_KEY value point Using BASIC in the Common Language Environment 19 7 Note that if the actual parameter s data type in the CALL statement does not match that specified in the EXTERNAL statement HP BASIC reports the compile time informational message Mode for parameter of routine changed to match declaration This tells you that HP BASIC has made a local copy of the value of the parameter and that this local copy has the data type specified in the EXTERNAL declaration HP BASIC warns you of this because the change means that the parameter can no longer be modified by the subprogram If HP BASIC cannot convert the data type HP BASIC signals the error Mode for parameter of routine not as declared The routine being called receives control executes and then returns control to the calling routine at the next statement after the CALL statement or function invocation HP BASIC provides the built in function LOC to allow you to access the address of a named external function This is especially useful when passing the address of a callback or AST routine to an external subprogram In the following example the address of the fu
265. ary with the DCL command LIBRARY Specify a library file specification as well as a list of the program modules you want to insert into the library For example BASIC MODULE1 MODULE2 LIBRARY CREATE TESTLIB1 OLB MODULE1 0OBJ MODULE2 OBJ In the previous example the BASIC command creates object files from MODULE1 BAS and MODULE2 BAS The LIBRARY command creates an object module library named TESTLIB1 OLB and inserts MODULE1 OBJ and MODULE2 OBJ into that library See the HP OpenVMS DCL Dictionary for more information about the LIBRARY command Accessing User Supplied Object Module Libraries To access user supplied object module libraries specify the LIBRARY qualifier to the DCL command LINK For example LINK MAIN TESTLIB LIBRARY This command instructs the linker to search the library TESTLIB OLB for any unresolved symbols in the HP BASIC object module MAIN OBJ Also you can explicitly include a module from a library with the INCLUDE qualifier For example LINK MAIN TESTLIB LIBRARY INCLUDE modulel module2 This command instructs the linker to include module1 and module2 from the library TESTLIB OLB whether or not it needs these modules to resolve symbols You can access user supplied object module libraries automatically However a program executing at DCL level does not automatically search libraries that are assigned to the logical name BASIC LIBO Instead the linker searches libraries that are assigned to
266. at attempts to assign more than two dimensions to an array This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Change the number of dimensions in the MAT statement to one or two ON_STAOUT ON statement out of range ERR 58 Explanation The index value in an ON GOTO or ON GOSUB statement is less than one or greater than the number of line numbers in the list User Action Check program logic to make sure that the index value is greater than or equal to one and less than or equal to the number of line numbers in the ON GOTO or ON GOSUB statement OUTOF_DAT Out of data ERR 57 Explanation A READ statement requested additional data from an exhausted DATA list User Action Remove the READ statement reduce the number of variables in the READ statement or supply more DATA items PRIKEYOUT Primary key out of sequence ERR 158 Explanation RMS has detected an error in a sequential PUT to an INDEXED file User Action Change the PUT statement If this does not work the file is corrupted and you cannot do anything PRIUSIFOR PRINT USING format error ERR 116 Explanation The program contains a PRINT USING statement with an invalid format string User Action Change the PRINT USING format string PROC_TRA Programmable C trap ERR 28 Explanation A CTRL C was typed at the controlling terminal User Action None however you can trap this erro
267. ation ERROR An OPEN statement s MAP clause references a nonexistent MAP User Action Define the MAP referenced by the MAP clause or remove the MAP clause MAPTOOLAR MAP too large in OPEN Explanation FATAL The size of the MAP referenced in an OPEN statement is greater than 32 767 bytes User Action Reduce the size of the MAP Compile Time Error Messages A 55 MAPVARALIT variable lt name gt not aligned in multiple references in MAP lt name gt Explanation ERROR More than one overlaid MAP contains the same variable but the variable s position differs in the MAPs User Action The same variable can appear in multiple overlaid MAPs but the variable must occupy the same position in the PSECT make sure that the variable appears in the same position in the MAPs MAPVARREF MAP variable lt name gt referenced before declaration Explanation INFORMATION A reference to a MAP variable occurs before the MAP statement User Action Make sure that the MAP statement precedes any references to variables in the MAP MATDIMERR matrix dimension error Explanation ERROR The program either e Contains a MAT IDN MAT TRN or MAT INV performed on a one dimensional array e Performs a matrix operation that requires identical subscripts in the operand arrays and those arrays have different subscripts User Action Dimension the arrays to the proper number of subscripts MATLOWBOU matrix must have lower bound 0 and
268. available HP BASIC requires a main program to receive the transfer of control User Action Supply a main program NOTRECVBY lt item gt may not be received by lt mechanism gt Explanation ERROR A subprogram specifies an invalid parameter or an incorrect passing mechanism for a parameter s data type For example you cannot receive an entire array BY VALUE User Action Specify a valid parameter or passing mechanism NOTXTROOM out of memory for statement text Explanation ERROR The program contains more text than HP BASIC allows User Action Split the program into one or more program units NOVALUE lt text gt keyword requires a value Explanation ERROR A keyword command was typed without a value User Action Supply a valid keyword value NUMARREXP numeric array expected Explanation ERROR A CHANGE statement does not specify a numeric array User Action Supply a numeric array in the CHANGE statement NUMCONREQ numeric constant required Explanation ERROR The program contains a string in a context that requires a numeric constant For example DECLARE INTEGER CONTANT A ABC User Action Supply a numeric constant A 64 Compile Time Error Messages NUMIS_NEE numeric expression is required Explanation ERROR The program contains a string expression in a context that requires a numeric expression for example WHILE A User Action Supply a numeric expression NUMVARREQ numeric v
269. bed in Section 21 2 2 Refer to the CDD Repository documentation for detailed information about the CDO utility and the compatibility dictionary Dictionary Path Names To access dictionary definitions you must specify a path name in the INCLUDE FROM CDD or REPORT DEPENDENCY directive The path name tells CDD Repository where to locate a particular data definition in its directory A CDD Repository path name consists of a string of names separated by periods and enclosed in quotation marks The origin is the top or root of a dictionary directory This directory contains other dictionary directories subdictionary directories and objects HP BASIC allows the following types of valid path name parameters when referring to CDO dictionary definitions They differ in the method of specifying the dictionary origin e Dictionary anchor path name 21 2 Using CDD Repository with BASIC An anchor path name begins with an anchor which is an OpenVMS directory specification as the dictionary origin The anchor specifies the OpenVMS directory that contains the CDO dictionary This is known as the CDO naming convention In the following example MYNODE DISK 2 MYDIRECTORY is the anchor MYNODE DISK 2 MYDIRECTORY PERSONNEL EMPLOYEES REC CDD TOP path name Use this to refer to either DMU format dictionary definitions or CDO format dictionary definitions in a compatibility dictionary The path origin is always CDD TOP This is k
270. boundaries for the supported data types 2 18 Developing HP BASIC Programs Table 2 1 Natural Boundaries For Supported Data Types Data Type Natural Boundary BYTE BYTE DECIMAL BYTE DOUBLE QUADWORD DYNAMIC STRING BYTE GFLOAT QUADWORD LONG LONGWORD QUAD QUADWORD RECORD Depends on contents RFA BYTE SFLOAT LONGWORD SINGLE LONGWORD STATIC STRING BYTE TFLOAT QUADWORD WORD WORD XFLOAT OCTAWORD WARNINGS NOALIGNMENT the default causes the compiler not to issue any warning messages about unaligned data The compiler naturally aligns all local variables and arrays but it is the responsibility of the BASIC programmer to naturally align COMMONSs MAPS and RECORDs The WARNINGS ALIGNMENT qualifier flags all occurrences of non naturally aligned items This helps the programmer identify and correct unaligned entities An entity can be unaligned in the following ways e The entity does not start on a natural boundary for its data type There are several actions a programmer can take to resolve this Rearrange the RECORD MAP or COMMON so that all entities start on natural boundaries Force proper alignment with fill items as needed Note that the natural alignment for a RECORD is equal to the largest alignment required by any of its fields As an example if a RECORD has a byte long and double field the alignment of the RECORD would be quadword Developing HP BASIC Programs 2 19 e For arrays of R
271. catch it PRINT ERROR NUMBER IS ERR PRINT ERROR AT LINE ERL PRINT ERROR MESSAGE IS ERTS ERR END HANDLER 500 END Output ERROR NUMBER IS 50 ERROR AT LINE 20 ERROR MESSAGE IS Data format error A READ statement is not valid without at least one DATA statement If your program contains a READ statement but no DATA statement BASIC signals the compile time error READ without DATA READ statements can appear either before or after their corresponding DATA statements The only restriction is that the DATA statements must be in the same order as their corresponding READ statements You can have more than one DATA statement in a program DATA statements are ignored without at least one READ statement You can use an ampersand to continue a DATA statement For example 10 DATA ABRAMS BAKER CHRISTENSON amp DOBSON EISENSTADT FOLEY Comment fields are not allowed in DATA statements For example the following statements cause A to contain the string ABC COMMENT READ AS DATA ABC COMMENT When you compile a program BASIC creates one data block for each program unit Each data block is local to the program or subprogram containing it this means that you cannot share DATA statements between program modules 5 6 Simple Input and Output The data block contains the values in all DATA statements in that program unit These values are stored in line number order Each time BASIC executes a READ statement
272. ccess records in an indexed file The example opens an indexed file and displays the first 25 records with serial numbers greater than AB2721 in ascending primary key value order MAP Bec STRING Owner 30 LONG Vehicle number amp STRING Serial number 22 OPEN VEH IDN FOR INPUT AS FILE 2 amp ORGANIZATION INDEXED PRIMARY KEY Serial number amp MAP Bec ACCESS READ GET 2 KEY 0 EQ AB2721 FOR I 1 TO 25 GET 2 PRINT Vehicle Number Vehicle number PRINT Owner is Owner E PRINT NEXT I File Input and Output 13 17 The following example performs random GET operations by specifying a record number MAP Bec STRING Owner 30 LONG Vehicle number amp STRING Serial number 22 OPEN VEH IDN FOR INPUT AS FILE 2 amp ORGANIZATION SEQUENTIAL FIXED amp MAP Bec ACCESS READ INPUT Which record do you want A WHILE A lt gt 08 GET 2 RECORD A PRINT The vehicle number is Vehicle number PRINT The serial number is Serial number PRINT The owner of vehicle Vehicle number is Owner INPUT Next Record A NEXT CLOSE 2 END You can specify an ALLOW clause in a GET statement if you have opened the file with ACCESS MODIFY or ACCESS WRITE and UNLOCK EXPLICIT The ALLOW clause lets you control the type of lock RMS places on the retrieved record ALLOW NONE specifies that no other users can access this record this is the default ALLOW READ lets other access streams
273. ce code of the next line to be executed DBG gt STEP stepped to TEST COUNTER LINE 27 27 X X4 1 DBG gt The PC is now at the first machine code instruction for line 27 of the module TEST line 27 is in COUNTER a routine within the module TEST TEST COUNTER LINE 27 is a directory specification The debugger uses directory specifications to refer to symbols However you do not need to use a path name in referring to a symbol unless the symbol is not unique in that case the debugger will issue an error message See the HP OpenVMS Using the OpenVMS Debugger with BASIC 3 5 Debugger Manual or online help for more information about resolving multiply defined symbols You can specify a number of lines for the STEP command to execute In the following example the STEP command executes three lines DBG gt STEP 3 Note that only those source lines for which code instructions were generated by the compiler are recognized as executable lines by the debugger The debugger skips over any other lines for example comment lines Also if a line has more than one statement on it the debugger will execute all the statements on that line as part of the single step Using the STEP OVER command to step over a GOSUB statement will still proceed to the target of the GOSUB since this statement is just a special kind of GOTO statement and not a routine call You can specify different stepping modes such as stepping by instruction rath
274. ce on the hardware If a program generates an arithmetic exception such as an overflow or divide by zero certain statements surrounding the offending statement may or may not be executed as a result of this reordering Consider this example A B C D E G F 2 16 Developing HP BASIC Programs If the value of E is zero the second statement will generate a divide by zero error As a result of instruction reordering it is possible that the assignment A B will not take place Further it is possible that the assignment G F will take place even though the previous statement generated an error The SYNCHRONOUS_EXCEPTIONS qualifier disables reordering Use this qualifier for programs that rely on arithmetic exceptions to occur at precise times during program execution The SYNCHRONOUS_EXCEPTIONS qualifier impacts only arithmetic exceptions and variable assignments in the immediate area of the excepting statement Very few programs should require the SYNCHRONOUS_EXCEPTIONS qualifier to produce correct results INTEGER REAL DECIMAL EXPLICIT TYPE_DEFAULT TYPE_DEFAULT REAL default The TYPE_DEFAULT qualifier lets you specify the default data type for numeric variables Remarks e EXPLICIT specifies that all program variables must be explicitly declared in DECLARE EXTERNAL COMMON MAP or DIM statements e INTEGER REAL or DECIMAL specify that only variables and data which are not explicitly declared default to int
275. ced it creates a variable with that name and data type and allocates storage for that variable BASIC Concepts and Elements 4 7 In the following example two INTEGER variables are created A and B Even though the values assigned to these variables are REAL the values are converted to INTEGER to match the data type specified for the variables The sum of these two values is therefore 30 not 30 6 as it would be if the variables were named A and B AS 10 1 BS 20 5 PRINT A B 30 4 5 2 Explicit Data Typing With explicit data typing you use a declarative statement to name and specify a data type for your program values BASIC provides the following declarative statements These statements create variables and allocate storage DECLARE DIMENSION COMMON MAP The statement you choose depends on the way in which you will use the variables e DECLARE and DIMENSION allocate dynamic storage for variables storage is allocated when the program executes e COMMON and MAP statements allocate storage for variables statically storage is allocated when the program is compiled All declarative statements associate a data type with a variable For more information see Chapter 7 4 6 Constants A constant is a value that does not change during program execution Constants can be either literals or named constants and can be of any data type except RFA You can use the DECLARE CONSTANT statement to create named constants
276. ceed the range of the signed data structure continued on next page Using BASIC in the Common Language Environment 19 13 Table 19 4 Cont OpenVMS Usages OpenVMS Usage BASIC Implementation exit_handler_block RECORD EHCB LONG flink LONG handler_addr BYTE arg_count BYTE FILL 3 LONG status_value_addr END RECORD fab NA file_protection LONG floating_point SINGLE DOUBLE GFLOAT SFLOAT TFLOAT XFLOAT function_code RECORD function code WORD major function WORD subfunction END RECORD identifier LONG io_status_block RECORD iosb WORD iosb_field 1 to 4 END RECORD item_list_2 RECORD item_list_two GROUP item 15 VARIANT CASE WORD comp_length WORD code LONG comp_address CASE LONG terminator END VARIANT END GROUP END RECORD continued on next page 19 14 Using BASIC in the Common Language Environment Table 19 4 Cont OpenVMS Usages OpenVMS Usage BASIC Implementation item_list_3 RECORD item_list_3 GROUP item 15 VARIANT CASE WORD buf_len WORD code LONG buffer_address LONG length_address CASE LONG terminator END VARIANT END GROUP END RECORD item_list_pair RECORD item_list_pair GROUP item 15 VARIANT CASE LONG code LONG item_value CASE LONG terminator END VARIANT END GROUP END RECORD item_list_pair item_quota_list RECORD item_quota_list GROUP quota n VARIANT CASE BYTE quota_name LONG item_value CASE BYTE list_end END VARIANT END GROUP END RECORD lock_id LONG
277. ces and tabs 16 Converts multiple spaces and tabs to a single space 32 Converts lowercase letters to uppercase 64 Converts left brackets to left parentheses and right brackets to right parentheses 128 Discards trailing spaces and tabs Same as TRM function 256 Suppresses all editing for characters within quotation marks If the string has only one quotation mark HP BASIC suppresses all editing for the characters following the quotation mark All values are additive for example by specifying 168 you can perform the following e Discard leading spaces and tabs value 8 e Convert lowercase letters to uppercase value 32 e Discard trailing spaces and tabs value 128 The following example requests an input string discards all spaces and tabs converts lowercase letters to uppercase and converts brackets to parentheses LINPUT PLEASE TYPE A STRING input string new string EDIT input string 2 32 643 PRINT new string END Output PLEASE TYPE A STRING 88 abcpfaBj 5 5 88ABC 5 5 String Handling 11 17 11 7 Manipulating String Data with Multiple Maps Mapping a string storage area in more than one way lets you extract a substring from a string or concatenate strings In the following example the three MAP statements reference the same 108 bytes of data MAP emprec first name 10 amp last name 20 amp street numbers 6 amp streetS 15 amp
278. ch You can pass data of any HP BASIC data type to an HP BASIC subprogram including RFAs and RECORDs HP BASIC allows you to pass up to 255 parameters separated by commas The data can be any one of the following e Constants e Variables e Expressions e Functions e Array elements e Entire arrays but not virtual arrays For passing constants variables functions and array elements name them in the argument list For example CALL SUBO1l varl var2 CALL SUB02 Po num Vouch 66 67 Cust_list 5 FNA B However when passing an entire array you must use a special format You specify the array name followed by commas enclosed in parentheses The number of commas must be the number of array dimensions minus one For example array_name is a one dimensional array array_name is a two dimensional array array_name is a three dimensional array and so on The following example creates a three dimensional array loads the array with values and passes the array to a subprogram as a parameter The subprogram can access and change values in array elements and these changes remain in effect when control returns to the main program Program Segmentation 12 5 PROGRAM fill array OPTION TYPE EXPLICIT DECLARE LONG I J K three d 10 10 10 EXTERNAL SUB example sub LONG DIM FOR I 0 TO 10 Z FOR J 0 TO 10 FOR K 0 TO 10 three d I J K I J K NEXT K NEXT J NEXT I CALL example sub three d END PROGRAM
279. ch are divided into groups by facility all system services share the same facility prefix SYS However these services are logically divided into groups that perform similar tasks Table 19 3 describes these groups Using BASIC in the Common Language Environment 19 11 Table 19 3 System Services Group Types of Tasks Performed AST Change Mode Condition Handling Event Flag Information Input Output Lock Management Logical Names Memory Management Process Control Security Time and Timing Allows processes to control the handling of ASTs Changes the access mode of particular routines Designates condition handlers for special purposes Clears sets reads and waits for event flags and associates with event flag clusters Returns information about the system queues jobs processes locks and devices Performs I O directly without going through RMS Enables processes to coordinate access to shareable system resources Provides methods of accessing and maintaining pairs of character string logical names and equivalence names Increases or decreases available virtual memory controls paging and swapping and creates and accesses shareable files of code or data Creates deletes and controls execution of processes Enhances the security of OpenVMS systems Schedules events and obtains and formats binary time values 19 4 3 System Routine Arguments All of the system routine arguments are described i
280. ch_name Once this record is found and retrieved the Rm_num field of that record is updated the program then prompts for another Search_name If a match is not found BASIC prints the message No such record and prompts the user for another Search_name The program ends when the user enters a null string for the Search_name value 20 MAP AAA STRING L name 60 F name 20 Rm num 8 30 OPEN STU DAT FOR INPUT AS FILE 93 amp ORGANIZATION SEQUENTIAL FIXED MAP AAA 50 INPUT Last name Search names 55 Search name EDIT Search_name 1 60 IF Search name THEN GOTO 32010 END IF 65 RESTORE 9 70 WHEN ERROR IN 75 GET 9 WHILE Search name lt gt L name USE IF ERR 11 THEN PRINT No such record CONTINUE 50 ELSE EXIT HANDLER END IF END WHEN 80 INPUT Room number Rm num 90 UPDATE 9 100 GOTO 50 32010 CLOSE 9 32030 PRINT Update complete 32767 END 13 22 File Input and Output 13 6 8 Note An UPDATE operation invalidates the value of the current record pointer The next record pointer is unchanged When you update a record in a relative variable file the new record can be larger or smaller than the record it replaces provided that it is smaller than the maximum record size set for the file When you update a record in an indexed variable file the new record can also be larger or smaller than the record it replaces The updated record e Can be no longer than the maximum
281. changed at run time with the REMAP statement The REMAP statement then redefines these variables to their appropriate sizes File Input and Output 13 7 MAP Emp rec FILLS 2048 MAP DYNAMIC Emp rec STRING Emp name LONG Badge STRING Address STRING Department RQ amp S REMAP Emp rec FILL Record offset Emp name 25 Badge Address 25 Department 4 RB RMM Note that when accessing virtual or sequential files you can specify a RECORD clause for the GET statement The following example opens a virtual file with each block containing 512 bytes However each block contains 4 logical records that are 128 bytes long Each of these logical records consists of a 20 character first name field a 44 character last name field and a 64 character company name field DECLARE WORD Record_number MAP Virt STRING FILL 512 MAP DYNAMIC Virt STRING First name amp Last name amp Company OPEN VIRT DAT FOR INPUT AS FILE 5 amp VIRTUAL MAP Virt Record number 1 WHEN ERROR IN WHILE 1 GET 5 RECORD Record number FOR I 0 TO 3 REMAP Virt STRING FILL I 128 amp First name 20 amp Last_name 44 amp Company 64 PRINT First name Last name Company NEXT I Record number Record number 1 NEXT USE IF ERR 11 THEN PRINT Finished CONTINUE 32767 ELSE EXIT HANDLER END IF END WHEN END 13 8 File Input and Output 13 5 3 After the first 512 byte block i
282. cification in the first line does not contain a file name the OPEN statement opens the tape drive for device specific I O The second line opens an ANSI format tape file using RMS because a file name is part of the file specification The following sections describe both I O to ANSI format magnetic tapes and device specific I O to magnetic tape unit record and disk devices For more information about I O to RMS disk files see Chapter 13 18 1 RMS I O to Magnetic Tape HP BASIC supports I O to ANSI formatted magnetic tapes When performing T O to ANSI formatted magnetic tapes you can read or write to only one file on a magnetic tape at a time and the files are not available to other users ANSI tape files are RMS sequential files Advanced File Input and Output 18 1 18 1 1 Allocating and Mounting a Tape You should allocate the tape unit to your process before starting file operations For example ALLOCATE MT1 This command assigns tape drive MT1 to your process You must also set the tape density and label with the MOUNT command Optionally you can specify a logical name to assign to the device in this case TAPE MOUNT DENSITY 1600 MT1 VOL001 TAPE When mounting a TK50 you cannot specify a density If the records do not specify the size of the block no value in HDR 2 specify the BLOCKSIZE as part of the MOUNT command For example MOUNT DENSITY 1600 BLOCKSIZE 128 MT1 VOL020 TAPE Alternatively you can use
283. cified in an EXTERNAL FUNCTION statement matches the data type specified in the FUNCTION statement If you declare a FUNCTION subprogram with an EXTERNAL statement and use the CALL statement to invoke the function it executes correctly but the function value is not available Note that BASIC still performs parameter validation when you invoke a function with the CALL statement Note that you cannot use the CALL statement to invoke a string or packed decimal function Program Segmentation 12 9 12 5 Returning Program Status A PROGRAM unit lets you return a status from an HP BASIC image by optionally including an integer expression with the END PROGRAM and EXIT PROGRAM statements After executing a program you can examine this status by checking the DCL symbol STATUS By default HP BASIC returns a status of 1 indicating success Success is signaled with an odd numbered status value while an error is signaled with an even numbered value STATUS contains the same value as the integer expression for the exit status in the EXIT and END PROGRAM statements Note that if a program is terminated with an EXIT PROGRAM statement the expression on the EXIT PROGRAM statement overrides any expression on the END PROGRAM statement In the following example exit_status contains the status value returned by the program After program execution STATUS has the value of exit_status You can examine the value of STATUS and display the corresponding messa
284. cifies more than the allowed number of dimensions User Action Reduce the number of dimensions to 32 or less MAXKEYSEG maximum of 8 key segments exceeded Explanation ERROR An OPEN statement specifies a segmented key with more than eight segments User Action Reduce the number of segments in the KEY clause to eight or less MAXPAREXC maximum parameters exceeded for lt name gt Maximum is lt number gt Explanation ERROR The program attempts to declare a DEF with more than eight parameters or a subprogram with more than 255 parameters User Action Reduce the number of parameters DEFs allow up to eight parameters and subprograms allow up to 255 parameters MAXPAREXP no more than lt number gt parameter s expected for lt sub func name gt Explanation ERROR An external SUB or FUNCTION was called with more parameters than were specified in the EXTERNAL statement including both OPTIONAL and non OPTIONAL parameters User Action Reduce the number of parameters in the call Compile Time Error Messages A 57 MERGE merged lt item gt and lt item gt Explanation ERROR The program contains a syntax error HP BASIC assumes that there is an incorrect space for example PR INT Compilation continues so that other errors can be detected The actual program line remains unchanged and no object file is produced User Action Examine the line carefully to discover the error Change the program line to correct the
285. city 20 amp states 2 amp zips 5 amp wage class 2 amp date of reviewS 8 amp salary ytd 10 amp tax ytd 10 MAP emprec full name 30 amp address 48 amp salary info 30 MAP emprec employee record 108 You can move data into a map in different ways For instance you can use terminal input arrays and files In the following example the READ and DATA statements are used to move data into a map READ EMPLOYEE RECORDS DATA WILLIAM DAVIDSON 2241 MADISON BLVD amp SCRANTON PA14225A912 10 78 13 325 77 925 31 Because all the MAP statements in the previous example reference the same storage area emprec you can access parts of this area through the mapped variables as shown in the following examples Example 1 PRINT full names PRINT wage class PRINT salary ytd Output 1 WILLIAM DAVIDSON A9 13 325 77 Example 2 PRINT last_name PRINT tax_ytd 11 18 String Handling Output 2 DAVIDSON 925 31 You can assign a new value to any of the mapped variables The following example prompts the user for changed information by displaying a menu of topics The user can then choose which topics need to be changed and then separately assign new values to each variable Loop_1 WHILE 1 1 INPUT Changes please type YES or NO CHS EXIT Loop 1 IF CHS NO PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT INPUT CASE CASE CASE
286. clause You may then optionally specify an ALLOW clause on the GET and FIND statements The ALLOW clause on a GET or FIND statement specifies the type of access allowed by other programs to the record while you are accessing it The following statement specifies that other programs may read but not modify the records you have locked GET 1 ALLOW READ 13 24 File Input and Output 13 6 9 If you specify UNLOCK EXPLICIT when opening a file all records that you retrieve remain locked until you explicitly unlock them with a FREE UNLOCK or CLOSE statement Gaining Access to Locked Records If you are trying to access a record that is currently locked one possible solution is to use the REGARDLESS clause on the GET or FIND statement The REGARDLESS clause is useful when you are interested in having only read access to the specified record Be aware however that using the REGARDLESS clause to read a locked record can lead to unexpected results because the record you read can be in the process of being changed by another program Another solution is to include a WAIT clause on the GET or FIND statement Note that you cannot specify a WAIT clause and a REGARDLESS clause on the same statement line By specifying the WAIT clause you can tell RMS to wait for a locked record to become available You can optionally specify an integer expression from 0 to 255 with the WAIT clause This integer expression indicates the number of seconds RMS shoul
287. code The following list describes the OPTIMIZE TUNE options GENERIC default selects instruction tuning that is appropriate for all implementations of the Itanium or Alpha architecture HOST selects instruction tuning that is appropriate for the Itanium or Alpha machine on which the code is being compiled EV4 selects instruction tuning for the 21064 21064A 21066 and 21068 implementation of the Alpha architecture EV5 selects instruction tuning for the 21164 implementation of the Alpha architecture EV56 selects instruction tuning for the 21164 implementation of the Alpha architecture PCA56 selects instruction tuning for the 21164PC implementation of the Alpha architecture EV6 selects instruction tuning for the 21264 implementation of the Alpha architecture EV67 selects instruction tuning for the 21264A implementation of the Alpha architecture ITANIUM2 selects instruction tuning for the Itanium 2 implementation of the Itanium architecture MERCED selects instruction tuning for the Merced implementation of the Itanium architecture Developing HP BASIC Programs 2 13 Remarks e Specify NOOPTIMIZE if you specify DEBUG when compiling a program NOOPTIMIZE expedites and simplifies the debugging session by putting the machine code in the same order as the lines in the source program Optimizations can cause unexpected and confusing behavior in a debugging session e Specifying OPTIMIZE the default usually m
288. command line or code line indicates that the command or statement continues on the following line All numbers in text are assumed to be decimal unless otherwise noted Nondecimal radixes binary octal or hexadecimal are explicitly indicated Mnemonics and Other Terms Used in Syntax Diagrams Angle in radians or degrees Array syntax rules specify whether the bounds or dimensions can be specified T O channel associated with a file Numeric expression that specifies a channel number Specific to a COMMON block Conditional expression indicates that an expression can be either logical or relational Conditional expression Constant value Data type keyword Decimal variable Array record or variable Specific to a DEF function Delimiter File specification device or logical name to be assigned a logical name Run time error number Expression External function External parameter File specification Specific to a FUNCTION subprogram Integer value Integer constant Expression that represents an integer value Variable that contains an integer value xxiii xxiv label lex lex exp lex var line line num lit log exp log name macro id map matrix name num num lit param list pass mech prog name real real exp real var rec exp rel exp relationship type replacement token routine str str exp str lit str var sub Alphanumeric statement label Lexical used to indicate a compone
289. constants as bounds The percent sign is optional for bounds however BASIC signals the error Integer constant required if a constant bound contains a decimal point The following statement creates a 101 element virtual array containing string data The elements of this array can each have a maximum length of 256 characters DIM 1 STRING VIRT_ARRAY 100 256 The following restrictions apply to the use of declarative DIM statements e A declarative DIM statement must lexically precede any reference to the array it dimensions e The lower bounds of all virtual array dimensions must be zero e You must open a VIRTUAL file on the specified channel before you can access elements of the virtual array 6 2 2 2 Executable DIM Statements Executable DIM statements have at least one variable bound Bounds can be constants or simple variables but at least one bound must be a variable Executable DIM statements let you redimension an array at run time The bounds of the array can become larger or smaller but the number of dimensions cannot change For example you cannot redimension a four dimensional array to be five dimensional The executable DIM statement cannot be used on arrays in COMMON MAP DECLARE or declarative DIM statements nor on virtual arrays or arrays received as formal parameters Whenever an executable DIM statement executes it reinitializes the array If you change the values of an executable DIM statement the
290. contains embedded blanks or invalid characters User Action Supply a valid file specification ILLILLACC Illegal or illogical access ERR 136 Explanation The requested access is impossible because e The attempted record operation and the ACCESS clause in the OPEN statement are incompatible e The ACCESS clause is inconsistent with the file organization e ACCESS READ or APPEND was specified when the file was created User Action Change the ACCESS clause ILLINIVAL Illegal initial value ERR 284 Explanation The current initial value specified on the SET INITIAL VALUE or LOCATE VALUE statement is beyond the range of possible values User Action Specify an initial value within the default range 0 through 1 or within the alternative range you optionally specified or change the range limits B 12 Run Time Messages ILLIO_CHA Illegal I O channel ERR 46 Explanation The program specified an I O channel outside the legal range User Action Specify I O channels in the range 1 to 99 inclusive or one returned from LIB GET_LUN ILLKEYATT Illegal key attributes ERR 137 Explanation The program specified CHANGES for the primary key User Action Remove the CHANGES specification from the primary key You can specify CHANGES only for alternate keys ILLLINSIZ Illegal line size ERR 275 Explanation The specified line size is less than or equal to zero User Action Specify a line size value greater than zero ILL
291. context Explanation ERROR An external function invocation including a parameter list appears on the left side of an assignment statement User Action Remove the assignment statement You cannot assign values to a function invocation FUNNESTOO function nested too deep Explanation ERROR The program contains too many levels of function definitions within function definitions User Action Reduce the number of nested functions FUNWHINOT exit from FUNCTION while not in FUNCTION Explanation ERROR An EXIT FUNCTION or FUNCTIONEXIT statement was found in a module that is not a FUNCTION subprogram User Action Remove the EXIT FUNCTION or FUNCTIONEXIT statement GRAARRMUS graphics array must be integer or real Explanation ERROR The specified array has a data type other than an integer or real data type User Action Declare the array with an integer or real data type HANNOTDEF HANDLER not allowed in DEF Explanation ERROR A HANDLER definition has been found within a DEF function definition User Action Remove the HANDLER definition from inside the DEF function definition A 34 Compile Time Error Messages HANNOTFOU error handler lt name gt not found Explanation ERROR You did not define the HANDLER you referenced in a WHEN statement User Action Define the HANDLER you reference in the WHEN statement HANNOTWHE HANDLER not allowed in a WHEN block or handler Explanation ERROR A detache
292. cord or group Explanation ERROR An OPEN statement contains a key specification that is not an unsubscripted WORD LONG QUAD STRING DECIMAL or an 8 byte RECORD or GROUP variable User Action Change the key specification to be an unsubscripted WORD LONG QUAD STRING DECIMAL or an 8 byte RECORD or GROUP variable KEYNOTMAP KEY lt vbl name gt is not an unsubscripted variable in MAP lt name gt Explanation ERROR An indexed file OPEN statement specifies a KEY variable that does not appear in a MAP statement User Action Place the KEY variable in the MAP referenced by the OPEN statement s MAP clause KEYREQMAP KEY clauses require a MAP clause Explanation ERROR An OPEN statement specifies KEY clauses without specifying a MAP clause User Action Supply a MAP clause to define the position of the keys in the record buffer KEYSEGMUS key segment lt name gt in map lt map name gt must be a string key Explanation ERROR An OPEN statement specifies a segmented key containing a numeric variable For example OPEN INDEX DAT AS FILE 1 ORGANIZATION INDEXED amp PRIMARY KEY AS B C MAP ABC User Action Specify only string variables in segmented keys KEYSINC lt keyword gt keyword inconsistent with lt keyword gt Explanation ERROR An OPEN statement contains contradictory record format specifications for example both FIXED and VARIABLE User Action Specify only one record format KEYTOO
293. ctice to declare all arrays explicitly before using them If you reference an element of an array that has not been explicitly declared BASIC creates a new array with the name you specify Arrays created by reference have default subscripts of 0 TO 10 0 TO 10 0 TO 10 0 TO 10 0 TO 10 0 TO 10 and so on depending on the number of dimensions specified in the array reference For example the following program implicitly creates three arrays and assigns a value to one element of each Arrays 6 7 LET A 5 5 5 3 14159 LET BS 3 33 LET C 2 2 Russell Scott END The first LET statement creates an 11 by 11 by 11 array that stores floating point numbers and assigns the value 3 14159 to element 5 5 5 The second LET statement creates an 11 element list that stores integers and assigns the value 33 to element 3 and the third LET statement creates an 11 by 11 string array and assigns the value Russell Scott to element 2 2 When you create an implicit numeric array by referring to an element BASIC initializes all elements except the one assigned a value to zero For implicit string arrays BASIC initializes all elements except the one assigned a value to a null string When you implicitly create an array you cannot specify a subscript greater than 10 An attempt to do so causes BASIC to signal Subscript out of range ERR 55 provided that subscript checking is enabled Note that you cannot create an
294. ctively 00200005 INPUT Statement INPUT LINE and LINPUT Statements Enabling and Disabling the Question Mark Prompt Providing Input from the Source Program READ and DATA Statements 02005 RESTORE Statement Program Output Print Zones The Comma and the Semicolon Output Format for Numbers and Strings Terminal Format Files Opening and Closing a Terminal Format File Writing Records to a Terminal Format File Overview of Arrays Creating Arrays Explicitly Creating Arrays with the DECLARE Statement Creating Arrays with the DIM Statement Declarative DIM Statements 200 Executable DIM Statements 0 2005 Creating Arrays with the COMMON Statement Creating Arrays with the MAP Statement Creating Arrays Implicitly Determining the Bounds of an Array 00000 Assigning and Displaying Array Values Assigning Values with the LET Statement Listing Array Elements with the PRINT Statement Using MAT Statements MAT Statement MAT READ Statement MAT INPUT Statement 4 11 4 11 4 12 4 13 4 13 4 14 5 1 5 1 5 3 5 4 5 5 5 6 5 7 5 8 5 9 5 12 5 13 5 14 5 14 6 1 6 2 6 3 6 4 6 5 6 5 6 6 6 7 6
295. ctor_longword_signed LONG array n vector_longword_unsigned LONG array n vector_quadword_signed QUAD array n vector_quadword_unsigned QUAD array n vector_word_signed WORD array n vector_word_unsigned WORD array n word_signed WORD word_unsigned WORD 2 2 Although unsigned data structures are not directly supported in BASIC you can substitute the signed equivalent provided you do not exceed the range of the signed data structure If a system routine argument is optional it will be indicated in the format section of the routine description in one of the following ways optional argument loptional argument If the comma appears outside the brackets you must either pass a zero by value or use a comma in the argument list as a placeholder to indicate the place of the omitted argument If this is the last argument in the list you must still include the comma as a placeholder If the comma appears inside the brackets you can omit the argument altogether as long as it is the last argument in the list Including Symbolic Definitions To enhance program development BASIC allows you to use symbolic definitions Symbolic definitions are names or symbols associated with values These symbols are used in many ways the value associated with a symbol can be a status code a mask or an offset into a data structure Many system routines depend on values that are defined in separate symbol definition files For example the stat
296. d HANDLER definition was found in a WHEN block protected region or associated handler User Action Remove the HANDLER definition from within all WHEN block protected regions and associated handlers HANWHINOT exit from HANDLER while not in HANDLER Explanation ERROR An EXIT HANDLER statement was found while not in a HANDLER block User Action Remove the EXIT HANDLER statement HFLOATNOTS HFLOAT is not supported Explanation ERROR HFLOAT floating point data type is not supported by Alpha BASIC User Action Remove the use of HFLOAT floating point data type substituting either GFLOAT TFLOAT or XFLOAT as appropriate HORJUSMUS horizontal justification must be LEFT CENTER RIGHT or NORMAL Explanation ERROR You specified an invalid value for the horizontal component of the SET TEXT JUSTIFY statement User Action Specify one of the values listed in the message IDEMAYAPP IDENT directive may appear only once per module Explanation WARNING The program contains more than one IDENT compiler directive User Action Remove all but one IDENT directive IDENAMTOO IDENT directive name is too long Explanation WARNING The quoted string in a IDENT directive is too long User Action Reduce the length of the string The maximum length is 31 characters Compile Time Error Messages A 35 IF_EXPMUS IF directive expression must be terminated by THEN directive Explanation ERROR A
297. d again E 6 F 3 G 4 Without the RESTORE statement line 30 would assign the following values E 7 F 9 G 2 5 2 Program Output The PRINT statement displays data on your terminal during program execution BASIC evaluates expressions before displaying results You can also print and format data with the PRINT USING statement For information about the PRINT USING statement see Chapter 14 When you use the PRINT statement HP BASIC does the following e Precedes positive numbers with a space and negative numbers with a minus sign e Prints a space after every number e Prints strings without leading or trailing spaces When an element in a list is not a simple variable or constant BASIC evaluates the expression before printing the value For example A 45 B 55 PRINT A B END Output 100 However BASIC interprets text inside quotation marks as a string literal A 45 B 55 PRINT A B END 5 8 Simple Input and Output Output A B The PRINT statement without an expression prints a blank line PRINT This example leaves a blank line PRINT PRINT between two lines END Output This example leaves a blank line between two lines 5 2 1 Print Zones The Comma and the Semicolon A terminal line contains zones that are 14 character positions wide The number of zones in a line depends on the width of your terminal a 72 character line contains 5 zones which start in columns 1 15 29 43 and 57 A 1
298. d allocate the device at DCL command level before reading or writing to the device For example this command allocates a card reader ALLOCATE CRI Once the device is allocated you can read records from it For example MAP DNG A 80 OPEN CR1 FOR INPUT AS FILE 1 ACCESS READ MAP DNG GET 1 HP BASIC treats the device as a file and data is read from the card reader as a series of fixed length records Device Specific I O to Magnetic Tape Devices When performing device specific I O to a tape drive you open the physical device and transfer data between the tape and your program GET and PUT statements perform read and write operations UPDATE and DELETE statements are invalid when you perform device specific I O Allocating and Mounting a Tape You must allocate the tape unit to your process before starting file operations The following command line assigns tape drive MT1 to your process ALLOCATE MT1 Use the DCL command MOUNT and the FOREIGN qualifier to mount the tape For example MOUNT FOREIGN MT1 Advanced File Input and Output 18 7 18 2 2 2 18 2 2 3 If your program needs a blocksize other than 512 bytes or a particular tape density specify these characteristics with the MOUNT command as well For example MOUNT FOREIGN BLOCKSIZE 1024 DENSITY 1600 MT1 When reading a foreign tape you must make sure the BLOCKSIZE qualifier has a value at least as large as the largest record on the tape
299. d decimal overflow checking e Program optimization e Rounding or truncation of packed decimal numbers e Subscript checking See the HP BASIC for OpenVMS Reference Manual for more information about the OPTION statement The OPTION statement in the following example specifies that all program variables must be explicitly typed and that all implicitly typed constants are INTEGER In addition any variable typed as INTEGER is a LONG integer and any variable typed as REAL is a DOUBLE floating point number 7 2 Data Definition SIZE REAL DOUBLE 64 bit floating point numbers by default OPTION TYPE EXPLICIT Variables must be declared amp CONSTANT TYPE INTEGER All implicit constants be integers amp SIZE INTEGER LONG 32 bit integers by default amp You can create variables of other data types by explicitly declaring them with the DECLARE COMMON or MAP statement 7 4 Declaring Variables A variable is a named quantity whose value can change during program execution Variables may be implicitly or explicitly declared HP BASIC accepts the following types of variables e Floating point e Integer e String e RFA e Packed decimal e Record For more information about declaring variables see the HP BASIC for OpenVMS Reference Manual 7 5 Declaring Named Constants A constant is a value that does not change during program execution You can declare named constants within a program unit with the DECLAR
300. d file missing line number on first line Explanation ERROR An attempt was made to append a source file that does not contain a line number on the first line User Action Put a line number on the first line of the appended file APPNOTALL append not allowed on programs without line numbers Explanation ERROR The APPEND command cannot be used on a program without line numbers User Action Use an include file ARESTYMUS area style must be HOLLOW SOLID PATTERN or HATCH Explanation ERROR You specified an invalid value in the SET AREA STYLE statement User Action Specify one of the values listed in the message Compile Time Error Messages A 5 AREREQTHR AREA output requires at least 3 X Y points Explanation ERROR An AREA graphic output statement specifies less than 3 points User Action Specify at least 3 points in the AREA graphic output statement ARGERR illegal argument for command Explanation ERROR An argument was entered for a command that does not take an argument or an invalid argument was entered for a command for example SCALE A or LIST A User Action Reenter the command with the proper arguments ARRMUSHAYV array must have 1 dimension Explanation ERROR An array with multiple dimensions is specified where a one dimensional array is required User Action Specify an array that has 1 dimension ARRMUSELE array must have at least 4 elements Explanation
301. d line number or label and so on If the control variable s value is less than 1 or greater than the number of targets in the list HP BASIC transfers control to the line number or label specified in the OTHERWISE clause If you do not supply an OTHERWISE clause and the control variable s value is less than 1 or greater than the number of targets BASIC signals ON statement out of range ERR 58 For example Program Control 9 17 INPUT Please enter first integer value First_value INPUT Please enter second integer value Second_value Choice PRINT Do you want to perform PRINT 1 Multiplication PRINT 2 Division PRINT 3 Exponentiation INPUT Selection ON Selection GOSUB Mult Div Expon OTHERWISE Wrong GOTO Done Mult Result First value Second value PRINT Results RETURN Div Result First_value Second value PRINT Results RETURN Expon Result First values Second_value PRINT Results RETURN Wrong PRINT Invalid selection RETURN Done END 9 7 Suspending and Halting Program Execution The following HP BASIC statements suspend program execution SLEEP WAIT These statements cause HP BASIC either to suspend program execution for a specified time or to wait a certain period of time for user input After execution of the last statement a HP BASIC program automatically halts and closes all files However you can explicitly halt program execution by using one o
302. d open the disk file you use the OPEN statement For example OPEN DUA3 FOR OUTPUT AS FILE 2 SEQUENTIAL FIXED amp RECORDSIZE 512 You can then write data to the disk The record size determined by the MAP or RECORDSIZE clause must be an integer multiple of 512 bytes Opening a Disk File for Input To open an existing disk file you also use the OPEN statement For example OPEN DUA1 FOR INPUT AS FILE 4 SEQUENTIAL FIXED amp RECORDSIZE 512 You can then read data from the disk The record size determined by the MAP or RECORDSIZE clause must be an integer multiple of 512 bytes The default is 512 Specify ACCESS READ in the OPEN statement if you only plan to read from the disk Writing Records to a Disk File You write data by defining a record buffer and writing the data to the file with PUT statements The following program writes eight 64 byte records into each 512 byte block on the disk When your program fills one block writing continues in the next The FILL field in the MOVE statement positions the data in the block Advanced File Input and Output 18 11 18 2 3 5 INPUT HOW MANY RECORDS TO WRITE J OPEN DBB2 FOR OUTPUT AS FILE 2 SEQUENTIAL FIXED amp RECORDSIZE 512 FOR K 1 TO J3 FOR I 0 TO 73 INPUT NAME OF BOOK BOOK NAMES INPUT RETRIEVAL NUMBER RET NUM INPUT SUBJECT AREA SUBJS MOVE TO 2 FILL I 64 BOOK NAMES RET NUM SUBJS NEXT I g PUT 23 NEXT K CLOSE
303. d wait for a locked record to become available If the record does not become available within the specified number of seconds RMS signals the error Keyboard wait exhausted ERR 15 If you do not specify an integer expression with the WAIT clause RMS waits indefinitely for the record to become available Once the record becomes available RMS delivers the record to the program Note that a deadlock condition can occur when you cause RMS to wait indefinitely for a locked record A deadlock condition occurs when two users simultaneously try to access locked records in each other s possession When a deadlock occurs RMS signals the error RMS DEADLOCK In turn HP BASIC signals the error Detected deadlock error while waiting for GET or FIND ERR 193 To handle this error you can either stop trying to access the particular record or if you must access the record free all locked records regardless of the channel and then attempt the GET or FIND again You need to unlock all records because you cannot know which record the other process wants File Input and Output 13 25 Note If the timeout value specified in the WAIT clause is less than the SYSGEN parameter DEADLOCK_WAIT then a Keyboard wait exhausted ERR 15 message can indicate that either the record did not become available during the specified time or there is an actual deadlock situation However if the timeout value is greater than the SYSGEN p
304. datatype is d floating base 16 my gfloat datatype is g floating end basicfloat structure end floats Translated RECORD Statement 1 SINCLUDE FROM CDD CDDSTOP BASIC FLOATS Cl Test of floating point data types C1 RECORD BASICFLOAT UNSPECIFIED Cl GROUP MY SINGLE F FLOATING C1 SINGLE SINGLE VALUE F Cl END GROUP cl DOUBLE MY DOUBLE D FLOATING Cl GFLOAT MY GFLOAT G FLOATING C1 END RECORD er ene i S BASIC I CDDATTSCA 1 CDD specifies SCALE for BASICFLOAT MY SINGLE Not supported BASIC E CDDATTBAS 1 CDD attributes for BASICFLOAT MY DOUBLE are other than base 10 In addition CDD Repository supports complex floating point numbers but HP BASIC does not support them Complex floating point numbers consist of a real and an imaginary part Each part requires the same amount of storage as a simple floating point number Therefore each complex floating point number requires twice as much storage as a simple floating point number If a CDD Repository data definition containing complex numbers is extracted HP BASIC signals the informational message Datatype in CDD Repository not supported substituted group for lt field name gt and creates a group to contain the field As before HP BASIC uses the data type and _VALUE to create the group name but because each complex number contains both a real and an imaginary part HP BASIC adds an _R to the name of the real part and an _I to the name of the ima
305. definition HP BASIC translates the data definition with lower bounds as zero and adjusts the upper bounds This means that an array with dimensions of 2 5 in CDD Repository is translated by HP BASIC to be an array with a lower bound of 0 and an upper bound of 3 HP BASIC issues an informational message to confirm the array bounds when you use this qualifier The following CDD Repository data definition and corresponding RECORD statement are extracted with the OLD_VERSION CDD_ARRAYS qualifier CDDL Definition define record CDDStop basic array2 description is test arrays with old_version CDD_ ARRAYS qualifier array 2 structure my byte array 0 2 datatype signed byte my string array 0 10 datatype text size 10 my s real array 0 2 0 4 datatype f floating my d real array 1 3 datatype d floating my g real occurs 4 times datatype g floating dep item datatype signed longword my h real occurs 4 times datatype h_floating end array 2 structure end array2 Using CDD Repository with BASIC 21 13 Translated RECORD Statement INCLUDE FROM CDD CDD TOP BASIC ARRAY2 test arrays with old version CDD ARRAYS qualifier RECORD ARRAY 2 a BYTE STRING SINGLE DOUBLE GFLOAT LONG HFLOAT MY BYTE 0 TO 2 UNSPECIFIED SIGNED BYTE MY STRING O TO 10 10 TEXT MY S REAL 0 TO 2 0 TO 4 F FLOATING MY D REAL 0 TO 2 MY G REAL 0 TO 3 DEP ITEM MY H REAL 0 TO 3 END RECORD 21 7 CDD Repository
306. dex will not change at all and the program will loop indefinitely To correct the problem you must delete the incorrect statement and recompile the source program 3 8 Hints for Using the OpenVMS Debugger A STEP at a statement that causes an exception might never return control to the debugger The debugger cannot determine what statement in the BASIC source code will execute after the exception occurs Therefore set explicit breaks if STEP is used on statements that cause exceptions Using the OpenVMS Debugger with BASIC 3 17 The following hints should help when you use the STEP command to debug programs that handle errors e When you STEP at a statement that takes an error the debugger will not regain control unless the program reaches an explicit breakpoint or the next statement that would have executed if no error had occurred Set explicit breaks if you want the program to stop in any other place e Use of the STEP command at a statement that takes an error does not return control to the debugger when the program reaches the error handler code If you want the program to break when program execution enters an error handler explicitly set a breakpoint at the error handler This applies to both ON ERROR handlers and WHEN handlers e If you are within a WHEN handler a STEP at a statement that terminates execution within the WHEN handler CONTINUE RETRY END WHEN END HANDLER EXIT HANDLER will not stop unless program flow reaches
307. directive See Section 16 4 5 for an example of using PRINT 16 4 5 IF THEN ELSE END IF Directive The IF THEN ELSE END IF directive lets you do the following things conditionally e Compile source text e Execute another compiler directive This directive differs from all others in that it can appear anywhere in a program where a space is allowed except within a quoted string 16 10 Compiler Directives You must include END IF Otherwise the rest of the source program becomes part of the THEN or ELSE clause You must also include a lexical expression and some BASIC source code The truth or falsity of the lexical expression determines whether BASIC compiles the source code in the THEN clause or the ELSE clause If the lexical expression is true BASIC does not compile the source code in the ELSE clause If the lexical expression is false BASIC does not compile the source code in the THEN clause However HP BASIC does check for lexical errors such as illegally formed numeric constants in the uncompiled block of code If an uncompiled block of code contains a lexical error HP BASIC signals an error Even though HP BASIC compiles only one block of code in an IF THEN EHLSE END IF directive you cannot use the same line number in both a THEN block and an ELSE block If you specify the same line number the first occurrence of the line number is replaced by the second when the program is compiled The follow
308. dling Default error handling is equivalent to ON ERROR GOTO 0 for main procedures and ON ERROR GO BACK for SUBs FUNCTIONs and DEFs For information about specific run time errors see Appendix B Handling Run Time Errors 15 23 16 Compiler Directives Compiler directives are instructions that tell HP BASIC to perform certain operations as it translates a source program This chapter describes how to control program compilation using compiler directives 16 1 Overview of Compiler Directives With compiler directives you can do the following Place program titles and subtitles in the header that appears on each page of the listing file Place a program version identification string in both the listing file and the object module Start or stop the inclusion of listing information for selected parts of a program Start or stop the inclusion of cross reference information for selected parts of a program Include HP BASIC code from another source file or a text library Include CDD Repository record definitions in a HP BASIC program Record dependency relationships in CDD Repository Display a message at compile time Conditionally compile parts of a program Terminate compilation When using compiler directives follow these rules Directives must begin with a percent sign Directives can be preceded by an optional line number Directives must be the only text on the line except for IF THEN ELSE END IF
309. e The use of the LINES qualifier can impede optimization LINES is needed in Alpha BASIC only for the ERL function and to print BASIC line numbers in run time error messages NOLINES is the default in Alpha BASIC Developing HP BASIC Programs 2 29 The default optimization level OPTIMIZATION LEVEL 4 provides the highest level of optimization The SYNCHRONOUS_EXCEPTIONS qualifier inhibits many optimiza tions For more information on SYNCHRONOUS_EXCEPTIONS see Section 2 1 2 2 3 1 3 Statements The statements used in a program can affect performance as follows If you use error handling the default ON ERROR GO BACK has the least impact on performance ON ERROR GOTO target and WHEN blocks have a greater impact If the application spends a large percentage of time in one routine consider writing the routine with default error handling if possible RESUME without a target impedes optimization This applies only to RESUME statements that do not specify a target A MOVE TO or FIELD statement limits optimizations in the entire routine SUB FUNCTION or main where the statement is found There is no additional cost for any statement after the first OPTION INACTIVE SETUP can dramatically minimize routine startup times by omitting RTL calls that initialize and close down routines For small BASIC routines the overhead of these RTL calls can be significant Use this option for routines that are frequently called I
310. e A B C User Action Remove the erroneous reference RECFILTOO lt field name gt from CDD Repository has FILL too large Explanation ERROR The total size of a CDD Repository record is greater than 65 535 bytes User Action Reduce the size of the record Compile Time Error Messages A 73 RECKEYQAD entire RECORD or GROUP must be 8 bytes in length Explanation ERROR The user attempts to specify an entire RECORD or GROUP name in a key value field on a GET or FIND statement and the size of the structure does not match the size of the QUADWORD User Action When specifying a quadword key use an 8 byte RECORD or GROUP otherwise specify the name of an elementary item in the RECORD or GROUP RECNOTBY record may not be passed BY lt mechanism gt Explanation ERROR The program attempts to pass a record to a subprogram using either the BY VALUE or BY DESC parameter passing mechanism User Action Remove the passing mechanism or specify BY REF HP BASIC programs can pass records only by reference RECNOTODEF record type lt name gt not defined Explanation ERROR The program declares an instance of a user data type but this type was not defined in the program module User Action Define the data type with a RECORD statement RECOVEMAP RECORDSIZE overflows MAP Explanation ERROR An OPEN statement contains both a RECORDSIZE clause and a MAP clause and the RECORDSIZE clause is larger than the MAP Us
311. e it does not change the file RESET is a synonym for RESTORE For example RESTORE 38 KEY 2 RESET 3 The RESTORE statement restores the file in terms of the second alternate key The RESET statement restores the file in terms of the primary key File Input and Output 13 29 The RESTORE statement can be used by all RMS file organizations RESTORE without a channel number resets the data pointer for READ and DATA statements but does not affect any files 13 6 13 Truncating Files The SCRATCH statement is valid only on sequential files Although you cannot delete individual records from a sequential file you can delete all records starting with the current record through to the end of the file In order to do this you must first specify ACCESS SCRATCH when you open the file To truncate the file locate the first record to be deleted Once the current record pointer points to this record execute the SCRATCH statement The following program locates the thirty third record and truncates the file beginning with that record OPEN MMM DAT AS FILE 23 amp SEQUENTIAL FIXED ACCESS SCRATCH first_bad_record 33 FIND 2 RECORD first bad record SCRATCH 2 CLOSE 2 END SCRATCH does not change the physical size of the file it reduces the amount of information contained in the file You can use the DCL command SET FILE TRUNCATE to truncate the excess file space Therefore you can write records with the PU
312. e pointer after the last record in the file when it opens the file for processing All subsequent PUT operations append the new record to the end of the existing file File Input and Output 13 19 MAP Buff STRING Code 4 Exp date 9 Type desig 32 OPEN INV DAT FOR INPUT AS FILE 28 amp ORGANIZATION SEQUENTIAL FIXED ACCESS APPEND amp MAP Buff WHILE 1 INPUT What is the specification code Code INPUT What is the expiration date Exp date INPUT What is the designator Type desig PUT 2 NEXT If the current record pointer is not at the end of the file when you attempt a sequential PUT operation to a sequential file BASIC signals Not at end of file ERR 149 In the following example the PUT statement writes records to an indexed file In this case the error message Duplicate key detected ERR 134 indicates that a record with a matching key field already exists and you did not allow duplicates on that key 10 MAP Purchase rec STRING R num 5 amp Dept_name 10 amp Pur dat 9 20 OPEN INFO DAT FOR OUTPUT AS FILE 2 amp ORGANIZATION INDEXED FIXED ACCESS WRITE amp PRIMARY KEY R num MAP Purchase rec 30 WHILE 1 INPUT Requisition number R num INPUT Department name Dept name INPUT Date of purchase Pur dat PRINT PUT 2 NEXT Requisition number 2522A Department name COSMETICS Date of purchase 15 JUNE 1985 Requisition number 2678D Department name AUTOMOTIVE
313. e CDD Repository record definition is corrupt or there is an internal error in either HP BASIC or CDD Repository User Action If the problem is not in the CDD Repository definition please submit a software problem report SPR with the source code of a small program that produces this error Compile Time Error Messages A 9 CDDACCREC CDD Repository error while accessing record Explanation ERROR CDD Repository reported an error when accessing the record The CDD Repository record definition is corrupt or there is an internal error in either HP BASIC or CDD Repository User Action If the problem is not in the CDD Repository definition please submit a software problem report SPR with the source code of a small program that produces this error CDDADJBOU adjusted bounds for dimension lt number gt of lt array gt to be zero based Explanation INFORMATION CDD Repository contains an array field with a lower bound that is not zero HP BASIC adjusts the bound so that the array is zero based User Action None CDDALCOFF please submit an SPR CDD Repository inconsistent with allocated offset for lt field name gt Explanation FATAL tThe offset of a field within an HP BASIC RECORD differs from the offset specified by CDD Repository for that record User Action Please submit a software problem report SPR with the source code of a small program that produces this error CDDALCSIZ please submit an SPR CDD Repos
314. e HP BASIC for OpenVMS Reference Manual 7 7 Allocating Dynamic and Static Storage HP BASIC programs allocate both dynamic and static storage Dynamic storage is allocated when the program executes whereas the size of static storage does not change during program execution Variables and arrays declared by the following means use dynamic storage e DECLARE statements e DIMENSION statements e Implicitly declared variables Normally string variables and arrays declared in these ways are dynamic strings and their length can change during program execution However if you declare or dimension an array of a user defined data type a RECORD name then all string variables and arrays are fixed length strings See Chapter 8 for more information about the RECORD statement Variables and arrays appearing in MAP or COMMON statements use static storage Hence all string variables appearing in MAP or COMMON statements are fixed length strings MAP and COMMON statements create a named storage area called a program section or PSECT MAP statements require a map name but in COMMON statements the name is optional The PSECT name is the same as the map or common name If you do not specify a common name HP BASIC supplies a default PSECT name of BLANK The remainder of this section explains how to use COMMON and MAP statements for static storage 7 4 Data Definition 7 7 1 COMMON Statement The COMMON statement defines a named area of storage
315. e There must be a line number on the first line of the program e Ifa source file contains subprograms then each subprogram must begin on a numbered line In a multiple unit program with line numbers any comments following an END END SUB or END FUNCTION statement become a part of the previous subprogram during compilation unless they begin on a numbered line This is not the case in multiple unit programs without line numbers Although line numbers are not required you might want to use them on every line that can cause a run time error depending on the type of error handling you use See Chapter 15 for more information about handling run time errors BASIC Concepts and Elements 4 1 4 1 2 Programs Without Line Numbers If you do not use line numbers in your program follow these rules e Use a text editor to enter and edit the program e No line numbers are allowed anywhere in the program module e The ERL function is not allowed e REM statements are not allowed In a multiple unit program without line numbers any comments following an END END SUB or END FUNCTION statement become a part of the next subprogram during compilation unless there is no next subprogram This is not the case in multiple unit programs with line numbers You can avoid all of these restrictions by placing a line number on the first line of your program no additional line numbers are required The line number on the first program line causes the compil
316. e Time Error Messages ENTARRFIE entire array field of virtual record cannot be passed Explanation ERROR The program attempts to pass an entire array as a parameter to a subprogram when e The array is an item in a record e The record is itself dimensioned as a virtual array User Action Assign the values of the array to another array that is of the same data type and dimension but that is not a field of a virtual array record and pass the second array as the parameter ENTARRNOT entire array not allowed in this context Explanation ERROR The program specifies an entire array in a context that permits only array elements for example in a PRINT statement User Action Remove the reference to the entire array ENTGRONOT entire GROUP or RECORD not allowed in this context Explanation ERROR The program specifies an entire GROUP or RECORD in a context that permits only GROUP or RECORD components for example PRINT ABC XYZ where XYZ is a GROUP User Action Remove the reference to the entire GROUP or RECORD ENTVIRARR entire virtual array cannot be a parameter Explanation ERROR The program attempts to pass an entire virtual array as a parameter User Action None You cannot pass an entire virtual array as a parameter EOLNOTTER End of line does not terminate IFs due to active blocks Explanation ERROR A THEN or ELSE clause contains a loop block and a line number terminates the if then else before the end of
317. e can have up to 31 characters If the function name ends with neither a percent sign nor a dollar sign the function returns a real number You can create user defined functions using these function naming rules however it is recommended that you use explicit data typing when defining functions for new program development See Chapter 12 for an example of an explicitly declared function Note that the function name must start with FN only if the function is not explicitly declared and a function reference lexically precedes the function definition DEF functions can be either single line or multiline Whether you use the single line or multiline format for function definitions depends on the complexity of the function you create In general multiline DEF functions perform more complex functions than single line DEF functions and are suitable for recursive operations If you want to pass values to a function the function definition requires a formal parameter list These formal parameters are the variables used to calculate the value returned by the function When you invoke a function you supply an actual parameter list the values in the actual parameter list are copied into the formal parameter at this time DEF functions allow up to 255 formal parameters You can specify variables constants or array elements as formal parameters but you cannot specify an entire array as a parameter to a DEF function Single Line DEF Functions In a
318. e for five floating point numbers 10 20 or 80 bytes of padding depending on the default size for floating point numbers 7 10 Data Definition You can specify user defined data types RECORD names for FILL items In the following example the first line defines a RECORD of data type X The MAP statement contains a fill item of this data type thus reserving space in the buffer for one RECORD of type X RECORD X REAL Y1 Y2 10 END RECORD X MAP QED X FILL See Chapter 8 for more information about the RECORD statement 7 7 4 Using COMMON and MAP Statements in Subprograms The COMMON and MAP statements create a block of storage called a PSECT This common or map storage block is accessible to any subprogram A HP BASIC main program and subprogram can share such an area by referencing the same common or map name The following example contains common blocks that define e A 16 character string field called A by the main program and X by the subprogram e A 10 character string field called B by the main program and Z by the subprogram e A 4 byte integer field called C by the main program and Y by the subprogram lIn a main program COMMON Al STRING A B 10 LONG C lIn a subprogram COMMON Al STRING X Z 10 LONG Y If a subprogram defines a common or map area with the same name as a common or map area in the main program it overlays the common or map defined in the main program Multiple COMMON statements with the
319. e instructions in the dialog box 22 4 Special Considerations for Handling Strings with DECwindows Motif All strings passed between DECwindows Motif and your program must be null terminated For example A string 0 C When passing a string argument to a DECwindows Motif routine the address of the string is required For static strings the address of the string can easily be obtained with the LOC function For example COMMON cl STRING hierarchy file name 21 hierarchy file name BASICSHELLOMOTIF UID 0 C DECLARE LONG hierarchy file name_array 1 hierarchy file name_array 0 LOC hierarchy file name 22 4 Using DECwindows Motif Bindings with BASIC Because dynamic strings are described by a descriptor a different means is needed to get the address of the string text The following helper function will get the address of dynamic strings as well as static strings FUNCTION LONG ADDRESS OF STRING STRING str_arg BY REF OPTION TYPE EXPLICIT INACTIVE SETUP END FUNCTION LOC str_arg Example of passing a dynamic string to a DECwindows Motif routine DECLARE STRING temp_string temp string A string value 0 C list_test DXmCvtFCtoCS ADDRESS OF STRING temp_string amp byte count istatus Using DECwindows Motif Bindings with BASIC 22 5 A Compile Time Error Messages This appendix describes compile time and compiler command errors their causes and the user action required to correct them A 1
320. e key field exceeds the maximum size of the record User Action Specify a key field within the record KEYLARTHA Key larger than record ERR 159 Explanation The key specification exceeds the maximum record size User Action Reduce the size of the key specification B 18 Run Time Messages KEYNOTCHA Key not changeable ERR 130 Explanation An UPDATE statement attempted to change a key field that did not have CHANGES specified in the OPEN statement User Action Remove the changed key field in the UPDATE statement or specify CHANGES for that key field in the OPEN statement Note that the primary key cannot be changed and that you cannot specify CHANGES when you open an existing file if the OPEN statement that created the file did not specify CHANGES KEYSIZTOO Key size too large ERR 145 Explanation The key length on a GET or FIND is either zero or larger than the key length defined for the target record User Action Change the key specification in the GET or FIND statement KEYWAIEXH Keyboard wait exhausted ERR 15 Explanation No input was received during the execution of an INPUT LINPUT or INPUT LINE statement that was preceded by a WAIT statement or INKEY timeout value User Action None you must supply input within the specified time LINTOOLON Line too long ERR 47 Explanation The program attempted to input more data than the input buffer can hold The default input buffer size for terminal input is
321. e numbers User Action Remove one instance of the duplicate line number Even if you compile the program without the ANSI_STANDARD HP BASIC will ignore all statements connected with the first instance of the duplicate line number before compiling the program DUPLNFND duplicate line number lt number gt found Explanation INFORMATION or WARNING Explanation INFORMATION A line number in an include file is the same as a line number in the main source file Explanation WARNING There are two lines in the main source file with the same line number HP BASIC keeps the second occurrence of the line number User Action Correct the source by changing one of the line numbers to an unused number DYNATTONL DYNAMIC attribute only valid for MAP areas Explanation ERROR A COMMON keyword is followed by the DYNAMIC keyword User Action Remove the DYNAMIC keyword The DYNAMIC attribute is valid only for MAP areas DYNSTRINH dynamic string variable lt name gt inhibits optimization Explanation INFORMATION This error is reported only when the NOSETUP qualifier is in effect The program contains a dynamic string variable This prevents optimization of the compiler generated code User Action Place the string variable in a COMMON keyword or MAP area Compile Time Error Messages A 25 ELENOALGN Elements within array lt array name gt are not naturally aligned Explanation WARNING lIdentifies record arrays that may not
322. e segmented the key can be composed of up to eight string variables in a map Quadword keys must be referenced using a record or group exactly 8 bytes long Along with the primary index key value you can also specify up to 254 alternate keys RMS creates one index for each key you specify For each of these keys you can also specify either an ascending or descending collating sequence Each index is stored as part of the file and each entry in the index contains a pointer to a record Therefore each key you specify corresponds to a sorted list of record pointers An indexed file of library books for example might be ordered by book title that is the title of the book is the primary key for the file The keys for alternate indexes might include the author s name and the book s Library of Congress number Neither of these alternate indexes contains the actual records instead they contain sorted pointers to the appropriate records Indexed files are most useful when randomly accessed or when you want to access the records in more than one way 13 2 5 Virtual Files A virtual file is a random access file that stores one or more data records or virtual array elements in each physical 512 byte disk block You create a virtual file by specifying ORGANIZATION VIRTUAL as part of the OPEN statement Apart from virtual arrays and compatibility with BASIC and BASIC PLUS 2 you should use sequential fixed length instead of virtual files as t
323. e specification ASSIGN DUAL SENDER PAYROL DAT PAYROLL DATA This example defines a logical name for a physical device ASSIGN DUA2 DISK2 Once you define the logical name you can reference that name in your program For example OPEN PAYROLL DATA FOR INPUT AS FILE 1 amp ORGANIZATION SEQUENTIAL OPEN DISK2 SORT DATA SORT LIS FOR OUTPUT AS FILE 2 amp SEQUENTIAL VARIABLE File Input and Output 13 13 13 6 2 13 6 3 These OPEN statements do not depend on the availability of DUA1 or DUA2 in order to work If these devices are not available you can redefine the logical names so that they specify other disk drives before running the program In addition you can redirect the entire file specification for PAYROLL_DATA to point to the test or production version of the data Creating Virtual Array Files BASIC virtual arrays let you define arrays that reside on disk You use them just as you would an ordinary array You create a virtual array by dimensioning an array with the DIM statement then opening a VIRTUAL file on that channel You access virtual arrays just as you do normal arrays The following DIM statement dimensions a virtual array on channel 1 The OPEN statement opens a virtual file that contains the array The last program line assigns a value to one array element DIM 1 LONG Int_array 10 10 10 OPEN VIRT DAT FOR OUTPUT AS FILE 1 VIRTUAL Int_array 5 5 5 100 Note that you canno
324. e total number of digits and the number of digits to the right of the decimal place that you want The following statement creates a packed decimal variable named My_decimal which can contain up to 8 digits 6 digits to the left of the decimal point and 2 digits to the right of the decimal point OPTION TYPE EXPLICIT DECLARE DECIMAL 8 2 My decimal Packed decimal numbers are most useful for dollars and cents calculations 4 7 4 String Variables Unlike some of the numeric variables described so far a string variable does not correspond to a single location in memory because a string variable is more likely to exceed a single location in memory Therefore the value of a string variable can be contained in any number of memory locations However a string variable is still referred to by a single name For example DECLARE STRING Employee_name 4 7 5 Subscripted Variables A subscripted variable is a floating point integer packed decimal RFA or string variable that is part of an array Chapter 6 describes arrays in more detail An array is a set of data organized in one or more dimensions A one dimensional array is called a list or vector A two dimensional array is called a matrix Arrays can have up to 32 dimensions When you create an array its size is determined by the number of dimensions and the maximum size called the bound of each dimension Subscripts begin by default with 0 not 1 That is when calculating the
325. eader block ANSI F or ANSI D You must specify ACCESS READ if the tape is not write enabled For example 100 OPEN TAPE PAYROLL DAT FOR INPUT AS FILE 4 ACCESS READ Positioning a Tape The NOREWIND statement positions the tape for reading and writing as follows e Specifying NOREWIND when you create a file positions the tape at the logical end of tape and leaves the unit open for writing If you omit NOREWIND you start writing at the beginning of the tape BOT logically deleting all subsequent files e Specifying NOREWIND when you open an existing file starts a search for the file at the current position The search continues to the logical end of tape If the record is not found HP BASIC rewinds and continues the search until reaching the logical end of tape again Omitting NOREWIND tells HP BASIC to rewind the tape and search for the file name until reaching the end of tape In either case you receive an error message if the file does not exist For example the following statement opens PAYROL DAT after advancing the tape to the logical end of tape If you omit NOREWIND the file opens at the beginning of the tape logically deleting all subsequent files OPEN MT1 PAYROL DAT FOR OUTPUT AS FILE 1 amp ORGANIZATION SEQUENTIAL NOREWIND Note that you cannot specify REWIND to avoid rewinding the tape omit the NOREWIND keyword Advanced File Input and Output 18 3 18 1 5 Writing Records to a File The PUT statement
326. eader that contains the length of the record excluding the header in bytes When your program retrieves a record this header is not included in the record buffer While variable length records usually make more efficient use of storage space than fixed length records manipulation of the record length headers generates processor overhead 13 1 3 Stream Records BASIC interprets stream records as a continuous sequence or stream of bytes Unlike the fixed and variable length formats stream records do not contain control information such as record counts segment flags or other system supplied boundaries Stream records are delimited by special characters or character sequences called terminators Note that stream record formats are valid only in sequential files RMS defines the following types of stream record formats e STREAM records can be delimited by any special character usually a carriage return line feed pair e STREAM_LF records must be delimited by a line feed character e STREAM_CR records must be delimited by a carriage return While you can access existing files of any one of these stream record formats BASIC creates new stream files only in the STREAM format you can create files of the other two stream record formats by modifying the RMS FAB control structure in a USEROPEN routine For more information about USEROPEN routines see Section 13 8 11 13 2 File Organizations HP BASIC provides the following file organiza
327. ed group for DECIMALSTRING MY_ RIGHT OVPNCH_NUMERIC CDD Repository supports the following additional data types BIT DATE POINTER UNSPECIFIED Using CDD Repository with BASIC 21 29 VIRTUAL ALPHABETIC HP BASIC does not support these data types HP BASIC translates these data types by signaling the informational message Datatype in CDD Repository not supported substituted group for lt field name gt and creates a group to contain the field See Table 21 2 for a description of how HP BASIC translates these data types If you extract a CDD Repository definition that contains a BIT field the field must be a multiple of 8 bits 1 byte This means that the following field must be aligned on a byte boundary If the following field is not aligned on a byte boundary HP BASIC signals the error Field lt name gt from CDD Repository has bit offset or length 21 30 Using CDD Repository with BASIC 22 Using DECwindows Motif Bindings with BASIC This chapter explains the BASIC language exceptions for using standard DECwindows Motif Bindings For more information about programming DECwindows Motif see the DECwindows Motif Guide to Application Programming 22 1 Overview of DECwindows Motif Concepts This section introduces DECwindows Motif concepts DECwindows Motif is an X Window System type of operating environment DECwindows Motif is used on a workstation where several windows can be displayed with different
328. ed record is transferred to the record buffer When your program writes a record data is transferred from the record buffer to the I O buffer and then to the file either when the I O buffer is full or when other blocks need to be read in You can use MAP statements to create static record buffers and associate program variables with areas fields of the buffer Static record buffers are buffers whose size does not change during program execution and whose program variables are always associated with the same fields in the buffer You can create dynamic record buffers with either a MAP DYNAMIC or a REMAP statement These statements when used after a MAP statement associate or reassociate a particular program variable with a different area field of the record buffer however the total size of a record buffer does not change during program execution Note If you do not specify a map you must use MOVE TO and MOVE FROM statements to transfer data back and forth from the record buffer to program variables however MOVE statements do not transfer data to or from a file 13 5 Accessing the Contents of a Record HP BASIC provides the following methods for accessing the contents of a record e MAP statement e MAP DYNAMIC and REMAP statements dynamic mapping 13 6 File Input and Output 13 5 1 13 5 2 e MOVE statements e FIELD statements The FIELD statement is a declining feature and is not recommended for new progra
329. ee Chapter 16 If you must redefine the variables in a PSECT you should use the MAP statement or a record with variants for each overlay When you use the MAP statement use the INCLUDE directive to create identical maps before redefining them as shown in the following example The map defined in MAP BAS is included in both program modules as a 40 byte string This map is redefined in the subprogram allowing the subprogram to access parts of this string 7 12 Data Definition MAP REDEF STRING full_name 40 In the main program SINCLUDE MAP BAS In the subprogram SINCLUDE MAP BAS MAP REDEF STRING first_name 15 MI 1 last_name 24 7 7 5 Dynamic Mapping Dynamic mapping lets you redefine the position of variables in a static storage area This storage area can be either a map name or a previously declared static string variable Dynamic mapping requires the following HP BASIC statements e A declarative statement such as a MAP statement allocating a fixed length storage area e A MAP DYNAMIC statement naming the variables whose positions can change at run time e A REMAP statement specifying the new positions of the variables named in the MAP DYNAMIC statement The MAP DYNAMIC statement does not affect the amount of storage allocated The MAP DYNAMIC statement causes HP BASIC to create internal pointers to the variables and array elements Until your program executes the REMAP statement the storage for each variab
330. effect User Action None syntax checking is not supported in ANSI mode SYSERROR system service error Explanation ERROR An error was detected while executing a system service User Action Take corrective action based on the associated message TEXFOLEND text following end of program unit must be on new lt type of line gt line Explanation ERROR The compiler detected text following an END END SUB or END FUNCTION statement User Action Remove the text In a multimodule source file with line numbers any text following an END END SUB or END FUNCTION statement must begin on a numbered line In a multimodule source file without line numbers any text following an END END SUB or END FUNCTION statement must begin on a new physical line A 84 Compile Time Error Messages TEXLINMSG text line exceeded 255 characters Explanation INFORMATION An input line contains more than 255 characters HP BASIC saves the first 255 input characters into the line buffer and ignores the rest of the input User Action Supply no more than 255 characters per input line to avoid truncation of input TEXPATMUS text path must be RIGHT LEFT UP or DOWN Explanation ERROR You specified an invalid value for the path specification of the SET TEXT PATH statement User Action Specify one of the values listed in the message TEXPREMUS text precision must be STROKE CHAR or STRING Explanation ERRO
331. efinition SUB deblock STRING input_rec STRING item MAP DYNAMIC input_rec STRING A 1 TO 3 REMAP input _rec amp A l 5 amp A 2 3 amp A 3 4 FOR I LBOUND A TO UBOUND A item I A I NEXT I END SUB Note that dynamic map variables are local to the program module in which they reside therefore REMAP only affects how that module views the buffer For more information about using the MAP DYNAMIC and REMAP statements see the HP BASIC for OpenVMS Reference Manual Data Definition 7 15 8 Creating and Using Data Structures A data structure is a collection of data items that can contain elements or components of different data types The RECORD statement lets you create your own data structures You use the RECORD statement to create a pattern of a data structure called the RECORD template Once you have created a template you use it to declare an instance of the RECORD that is a RECORD variable You declare a RECORD variable just as you declare a variable of any other type with the DECLARE statement or another declarative statement A RECORD instance is a variable whose structure matches that of the RECORD template The RECORD statement does not create any variables It only creates a template or user defined data type that you can then use to create variables This chapter describes how to create and use data structures 8 1 RECORD Statement The RECORD statement names and defines a data
332. eger real or packed decimal e INTEGER_SIZE REAL_SIZE and DECIMAL_SIZE cause the compiler to specify the actual size of variables and data VARIANT int const The VARIANT qualifier lets you specify the value associated with the lexical function VARIANT See Chapter 16 for more information about VARIANT and the VARIANT lexical function Developing HP BASIC Programs 2 17 Remarks e If VARIANT is not specified the default value is 0 e If VARIANT is specified without a value the default is 1 NO WARNINGS NOJINFORMATIONALS NO WARNINGS NOJALIGNMENT saa ALL NONE WARNINGS INFORMATIONAL WARNINGS WARNINGS INFORMATIONAL WARNINGS NOALIGNMENT default The WARNINGS qualifier lets you specify whether BASIC displays informational and warning messages Remarks e WARNINGS NOWARNINGS causes the compiler to display informa tional messages but not warning messages e WARNINGS NOINFORMATIONALS causes the compiler to display warning messages but not informational messages e NOWARNINGS causes the compiler to suppress any informational or warning messages e WARNINGS ALIGNMENT causes the compiler to flag all occurrences of non naturally aligned RECORD fields variables within COMMONSs and MAPs and RECORD arrays An aligned data item starts on an address that is natural for that data type Unaligned data accesses on Alpha can significantly reduce performance Table 2 1 lists the natural
333. element 1 1 It assigns the line you supply including commas semicolons and quotation marks but excluding the line terminator to an array element DIM emp nam 5 5 MAT LINPUT emp nam 2 2 PRINT emp nam 1 1 PRINT emp nam 1 2 PRINT emp nam 2 1 PRINT emp nam 2 2 END Output SMITH JONES WHITE BLACK SMITH JONES WHITE BLACK By specifying the subscripts 2 2 MAT LINPUT redimensions the array to nine elements and overwrites the old values assigning the values in the same manner as MAT INPUT see Section 6 6 3 BASIC then prompts for these elements 6 16 Arrays MAT LINPUT also excludes line terminators when assigning values to string array elements MAT LINPUT places the values from the open file into the specified array filling the array by rows starting with element 1 1 If there are more values in the file than there are array elements BASIC ignores the excess records If there are fewer BASIC assigns a null string to the remaining elements The following program reads 50 records from the open disk file and assigns them to the array named part_name If there are more than 50 records in the file BASIC ignores the excess records If there are fewer than 50 records then BASIC fills the remaining elements of the array with the null string DIM part_name 50 MAT LINPUT 1 part_name 6 6 5 MAT PRINT Statement The MAT PRINT statement prints some or all of an array s elements excluding
334. ement uses a conditional expression to control loop execution the loop is executed as long as a given condition is true A WHILE NEXT loop is useful when you do not know how many loop iterations are required In the following example the first statement instructs the user to input data and then type DONE when finished After the user enters the first piece of input HP BASIC executes the WHILE NEXT loop If the first input value is not DONE the loop executes and prompts the user for another input value 9 6 Program Control Once the user enters this input value the WHILE NEXT loop once again checks to see if this value corresponds to DONE The loop will continue executing until the user types DONE in response to the prompt INPUT Type DONE when finished Answer WHILE Answer lt gt DONE INPUT More data Answer NEXT Note that the NEXT statement in the WHILE NEXT and UNTIL NEXT loops does not increment a control variable your program must change a variable in the conditional expression or the loop will execute indefinitely The evaluation of the conditional expression determines whether the loop executes The test is performed that is the conditional expression is evaluated before the first iteration if the value is false 0 the loop does not execute It can be useful to intentionally create an infinite loop by coding a WHILE NEXT loop whose conditional expression is always true Whe
335. ent 00000 15 2 3 2 CONTINUE Statement 15 2 3 3 EXIT HANDLER Statement 15 2 4 Selecting the Severity of Errors to Handle 15 2 5 Identifying Errors 0 0 c ee eee 15 2 5 1 Determining the Error Number ERR 15 2 5 2 Determining the Error Line Number ERL 15 2 5 3 Determining Where the Error Occurred ERN 15 2 5 4 Determining the Error Message Text ERT 15 2 5 5 Determining OpenVMS Error Information 15 2 5 6 Determining RMS Error Information 15 2 6 Ctrl C Trapping 0 cee cee ee 15 2 7 Handling Errors in Multiple Unit Programs 15 2 8 Forcing Errors 0 0 e eee eens 15 3 Using the ON ERROR Statements 16 Compiler Directives 16 1 Overview of Compiler Directives 16 2 Controlling the Compilation Listing 16 2 1 TITLE and SBTTL Directives 16 2 2 FIDENT Directive 0 20 ee eee 16 2 3 PAGE Directive 2 0 ee 16 2 4 LIST and NOLIST Directives 16 2 5 CROSS and NOCROSS Directives 16 3 Accessing External Source Files 16 4 Controlling Compilation 00 16 4 1 OLET Directive ix ees ereseres aes Wg eG Re Be 16 4 2 VARIANT Directive 1 0 0 0 eee 16 4 3 ABORT Directive 0 0 0 0 ee 16 4 4 PRINT Directive 0 0 ce eee 16 4 5 IF THEN EL
336. ent disables this 30 second requirement for all subsequent INPUT statements WAIT 30 INPUT You have 30 seconds to type your password PSW WAIT 0 INPUT What directory do you want to go to DIRS Program Control 9 19 9 7 3 STOP Statement The STOP statement is a debugging tool that lets you check the flow of program logic STOP suspends program execution but does not close files When HP BASIC executes a STOP statement it signals STOP at line lt line num gt If you compile link and execute a program containing a STOP statement HP BASIC displays a number sign prompt when the STOP statement is encountered At this point you can enter e CONTINUE to continue program execution e EXIT to return to DCL command level 9 7 4 END Statement The END statement marks the end of a main program When HP BASIC executes an END statement it closes all files and halts program execution The END statement is optional in HP BASIC programs However it is good programming practice to include it The END statement must be the last statement in the main program The END statement returns you to DCL command level 9 20 Program Control 10 Functions A function is a single statement or group of statements that perform operations on operands and return the result to your program HP BASIC has built in functions that perform numeric and string operations conversions and date and time operations This chapter describes
337. ents in that they do not depend on run time flow of control The ON ERROR statements however affect error handling only if the statements execute at run time For example if a GOTO statement precedes an ON ERROR statement the ON ERROR statement will not have any effect because it does not execute 15 20 Handling Run Time Errors WHEN ERROR blocks let you handle errors that occur in a specific range of statements ON ERROR statements let you specify a general error handler that is in effect until you specify another ON ERROR statement or until you pass control to the HP BASIC error handler Note For all current program development it is recommended that you use WHEN ERROR constructs for user written error handlers Mixing WHEN ERROR constructs and ON ERROR statements within the same program is not recommended The ON ERROR statements are supported for compatibility with other versions of BASIC available from HP It is important to note that all of these statements are illegal within a protected region or an attached or detached handler The ON ERROR statements are documented in the HP BASIC for OpenVMS Reference Manual This section briefly describes the main features of the ON ERROR statements The ON ERROR statements can be used to transfer control to a labeled block of error handling code If you have executed an ON ERROR statement and an error occurs the ON ERROR statement immediately transfers control to the label or line
338. er simplifies the job of each language compiler because the logic needed to resolve symbolic references need not be duplicated The main advantage to a system that has a linker however is that individual program modules can be separately written and compiled and then linked together This includes object modules produced by different language compilers The linker performs the following functions e Resolves local and global symbolic references in the object code e Assigns values to the global symbolic references e Signals an error message for any unresolved symbolic reference e Produces an executable image When you link a program in development in order to enable debugging use the DEBUG qualifier with the LINK command The DEBUG qualifier appends to the image all the symbol and line number information appended to the object modules plus information about global symbols and forces the image to run under debugger control when you execute it unless you then specify NODEBUG The LINK command produces an executable image by default however you can also use the LINK command to obtain shareable images and system images The SHAREABLE qualifier directs the linker to produce a shareable image the SYSTEM qualifier directs the linker to produce a system image See Section 2 2 2 for a complete description of these and other LINK command qualifiers For a complete discussion of the OpenVMS Linker see the HP OpenVMS Linker Utility Manua
339. er Action Make the RECORDSIZE the same as the MAP size RECRECDEF recursive RECORD definition of type lt name gt Explanation ERROR The program contains two or more RECORD statements that reference each other User Action Change the program so that the RECORD statements do not point at each other RECTOBIGL record too big from module lt mod name gt in text library lt text lib name gt Explanation ERROR the text library module specified in a INCLUDE directive contains a record longer than 255 bytes User Action Extract the module from the text library edit it to remove any records longer than 255 bytes and replace the module in the text library A 74 Compile Time Error Messages RECTOOBIG record too big from INCLUDE directive file Explanation ERROR The file specified in a INCLUDE directive contains a record longer than 255 bytes User Action Edit the file to remove any records longer than 255 bytes RECTOOLAR RECORD too large Limit is 65 535 bytes Explanation ERROR The components of a RECORD definition add up to more than 65 535 bytes or 32 767 bytes if the RECORD is used as an array component User Action Reduce the size of the RECORD definition REMARRREF entire REMAPPED array lt name gt cannot be passed BY REF Explanation ERROR The program attempts to pass an array declared in a MAP DYNAMIC statement to an external subprogram by reference User Action Entire remapped arrays must be pas
340. er Format word BINARY NUMBER ZK 5173 GE Data Representation 17 1 17 1 2 Word Length Integer Format Word length integers are in the range 32768 to 32767 and are stored as two contiguous bytes starting on an arbitrary byte boundary Bits are labeled from the right 0 to 15 as in Figure 17 2 Figure 17 2 Word Length Integer Format k o 0 BINARY NUMBER ZK 5174 GE 17 1 3 Longword Integer Format Longword integers are stored as four contiguous bytes starting on an arbitrary byte boundary Values are in the range 2147483648 to 2147483647 See Figure 17 3 Figure 17 3 Longword Integer Format 31 0 BINARY NUMBER ZK 5175 GE 17 1 4 Quadword Integer Format Quadword integers are stored as eight contiguous bytes starting on an arbitrary byte boundary Values are in the range 9223372036854775808 to 9223372036854775807 See Figure 17 4 17 2 Data Representation Figure 17 4 Quadword Integer Format 63 0 BINARY NUMBER VM 0520A Al The compiler incorrectly gives an integer overflow message when the most negative integer constants are used as follows BYTE 128 WORD 32768 LONG 2147483648 QUAD 9223372036854775808 The workaround is to use the appropriate expression from the following BYTE 127 1 WORD 32767 1 LONG 2147483647 1 QUAD 9223372036854775807 1 17 2 Real Number Format 17 2 1 Real numbers like integers can be represented in varying forma
341. er at the end of string A this terminates the current line and causes B to begin on a new line INPUT LINE AS LINPUT BS LINPUT C PRINT A BS C PRINT DONE END Output SINGLE DOUBLE Return GFLOAT Return HFLOAT REAL Data Types Return SINGLE DOUBLE GFLOAT HFLOAT REAL Data Types DONE The INPUT INPUT LINE and LINPUT statements can accept data from a terminal or a terminal format file See Section 5 3 for information about I O to terminal format files 5 1 1 3 Enabling and Disabling the Question Mark Prompt With the SET PROMPT statement HP BASIC allows you to enable and disable the question mark prompt By default HP BASIC displays the question mark prompt The following example displays the default prompt string INPUT Please input 3 integer values A B C Output Please input 3 integer values You can however disable the question mark prompt by specifying the SET NO PROMPT statement SET NO PROMPT INPUT Please input 3 integer values A B C 5 4 Simple Input and Output Output Please input 3 integer values When you disable the question mark prompt you can specify your own prompt at the end of each prompt string The following example inserts a colon at the end of the prompt string SET NO PROMPT INPUT Please enter your name Employee_name Output Please enter your name Now if the SET PROMPT statement is specified BASIC displays both the colon and
342. er than by line SET STEP INSTRUCTION To resume to the default behavior enter the SET STEP LINE command Also by default the debugger steps over called routines execution is not suspended within a called routine although the routine is executed By entering the SET STEP INTO command you tell the debugger to suspend execution within called routines as well as within the currently executing module To resume the default behavior enter the SET STEP OVER command 3 4 2 Determining the Current Location of the Program Counter The SHOW CALLS command lets you determine the current location of the program counter PC for example after returning to the debugger following a Ctrl Y interrupt The command shows a traceback that lists the sequence of calls leading to the currently executing routine For example DBG gt SHOW CALLS module name routine name line rel PC abs PC TEST PRODUCT 18 00000009 0000063C TEST COUNTER 47 00000009 00000647 MY_PROG MY_PROG 21 0000000D 00000653 DBG gt For each routine beginning with the currently executing routine the debugger displays the following information e Name of the module that contains the routine e Name of the routine 3 6 Using the OpenVMS Debugger with BASIC e Line number at which the call was made or at which execution is suspended in the case of the current routine e Corresponding PC addresses the relative PC address from the start of the routine and the absolute PC address
343. er to compile your program as a program with line numbers When you write a program with or without line numbers you can begin your program statements in the first character position on a line To develop the following program use a text editor and observe the restrictions previously listed This is a short program that does not contain any BASIC line numbers This program must be entered using a text editor lit cannot be entered directly into the environment PRINT This program converts kilogram weight to pounds INPUT How many kilograms A This is the conversion factor B A 2 2 PRINT For A kilograms the pound weight is B END Output This program converts kilogram weight to pounds How many kilograms 11 For 11 kilograms the pound weight is 5 You can use exclamation comment fields instead of REM statements to insert comments into programs without line numbers An exclamation point in column 1 causes the HP BASIC compiler to ignore the rest of the line You can also identify program statements in programs without line numbers by using labels 4 2 BASIC Concepts and Elements 4 1 3 Labels A label is a 1 to 31 character identifier that you use to identify a block of statements All label names must begin with a letter the remaining characters if any can be any combination of letters digits dollar signs underscores _ or periods but the final character cannot be a dollar sign Labels ha
344. erminal format file Arrays 6 17 MAT INPUT A 5 PRINT MAT PRINT A PRINT MAT PRINT A A MAT PRINT 3 A A END Output 25 ol ol oooou 6 6 6 Matrix I O Functions NUM and NUM2 MAT statements do not signal error messages when there are more data items than array elements to contain them or when there are fewer data items than array elements to contain them BASIC provides two functions that let you determine how much data the MAT statements transfer NUM and NUM2 For two dimensional arrays the NUM function returns an integer value specifying the row number of the last data item transferred and the NUM2 function returns an integer value specifying the column number of the last data item transferred For one dimensional arrays the NUM function returns the number of items entered and the NUM2 function returns a zero With these functions you can determine the number of items transferred from a terminal format file Note however that you cannot use the NUM and NUM2 functions to implicitly declare an array In the following example the terminal format file EMP DAT contains the values 1 to 17 inclusive When these values are read with the MAT INPUT statement NUM and NUM2 represent the row and column number respectively of the last value read OPEN EMP DAT FOR INPUT AS FILE 3 DIM emp name 5 5 MAT INPUT 3 emp name PRINT NUM NUM2 END Output 4 2 6 18 Arrays 6 7 Matrix Operators BASIC prov
345. error User Action Take appropriate action based on the associated LBR message ERRREADFIL error reading file lt file_name gt Explanation ERROR the compiler encountered problems while reading either a BASIC source file or a CDD audit file as specified using the AUDIT qualifier User Action Examine the secondary message that follows this message to find out what went wrong then take the appropriate action ERRRECCOM erroneous RECORD component Explanation ERROR The program contains an erroneous record component for example specifying A B when RECORD A has no component named B User Action Remove the erroneous reference A 28 Compile Time Error Messages EXEDIMILL executable DIMENSION illegal for static array Explanation ERROR A DIMENSION statement names an array already declared with a DECLARE COMMON MAP or RECORD statement or one that was declared statically in a previous DIMENSION statement User Action Remove the executable DIMENSION statement or originally declare the array as executable in a DIMENSION statement EXPDECREQ explicit declaration of lt name gt required Explanation ERROR The program is compiled with the TYPE EXPLICIT qualifier in effect and the program references a variable constant function or subprogram name that is not explicitly declared User Action Explicitly declare the variable constant function or subprogram EXPIFDIR expecting IF directive Explanat
346. es not exist on the system e Specifying a logical name that is not defined e Specifying a file name that does not exist when the device type is for an input metafile e Specifying a file name for a device type that requires an OpenVMS physical device name User Action Specify an appropriate device name ILLECHARE Illegal echo area ERR 283 Explanation The specified echo area boundaries are invalid User Action Specify echo area boundaries within the device viewport Run Time Messages B 11 ILLEXIDEF Illegal exit from DEF HRR 245 Explanation A multiline DEF contains a branch to an END END SUB END DEF SUBEND or FUNCTIONEND statement This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Change the program logic so that the program executes the multiline function s END DEF or FNEND statement before executing the END END SUB END DEF SUBEND or FUNCTIONEND statement ILLFIEVAR Illegal FIELD variable ERR 122 Explanation A FIELDed variable is referenced after a non BASIC subprogram closed the file associated with that variable This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Check program logic do not reference the variable after the file has been closed ILLFILNAM Illegal file name ERR 2 Explanation A file name is 1 too long 2 incorrectly formatted or 3
347. es that you make to the parameter value in the routine do not affect the value of that parameter in the calling routine HP BASIC allows actual and formal parameters to be passed by value 19 2 Using BASIC in the Common Language Environment 19 1 4 HP BASIC Default Parameter Passing Mechanisms There are default parameter passing mechanisms established for every data type you can use with HP BASIC Table 19 1 shows which HP BASIC data types you can use with each parameter passing mechanism Table 19 1 Valid Parameter Passing Mechanisms Parameter BY VALUE BY REF BY DESC Integer and Real Data Variables Yes Yes Yes Constants Yes Local Local copy copy Expressions Yes Local Local copy copy Elements of a Yes Yes Yes nonvirtual array Virtual Yes Local Local array elements copy copy Nonvirtual No Yes Yes entire array Virtual No No No entire array Packed Decimal Data Variables No Yes Yes Constants No Local Local copy copy Expressions No Local Local copy copy Nonvirtual No Yes Yes array elements Virtual No Local Local array elements copy copy Specifies the default parameter passing mechanism continued on next page Using BASIC in the Common Language Environment 19 3 Table 19 1 Cont Valid Parameter Passing Mechanisms Parameter BY VALUE BY REF BY DESC Packed Decimal Data Nonvirtual No Yes Yes entire arrays Virtual No No No entire arrays String Data Va
348. es the OpenVMS operating system to its full advantage and is integrated with many other HP products In particular HP BASIC supports The OpenVMS systems standard calling procedures Record definitions included from the OpenVMS Common Data Dictionary Code analysis with the Performance and Coverage Analyzer PCA Creation of code with the Language Sensitive Editor LSE Extensive online language help Exchange of data with other systems using DECnet HP BASIC supports features of other versions of BASIC including PDP 11 BASIC PLUS 2 The FLAG qualifier allows you to check whether programs contain declining features that should be replaced with newer ones When you write programs in HP BASIC you develop programs at the DCL command level You write your source program with a text editor then compile link and run the program with commands to the OpenVMS operating system 1 2 Overview of HP BASIC 2 Developing HP BASIC Programs This chapter describes how to compile link and run an HP BASIC program For information about using a text editor to create and edit files see the OpenVMS User s Manual 2 1 Compiling an HP BASIC Program The HP BASIC compiler performs the following functions e Detects errors in your source program e Generates any appropriate error messages e Generates machine language instructions from the source statements e Groups these language instructions into an object module for the linker To invoke the comp
349. etected code that will never be executed for example a multistatement line whose first statement is a GOTO EXIT ITERATE RESUME or RETURN VAX BASIC only User Action Review the program to determine if the code should be executed If you determine the code should be executed then you should revise the program flow logic accordingly Otherwise the code is unnecessary and you may want to remove it In the case of the GOTO EXIT ITERATE RESUME or RETURN statements make sure that these statements are the only statements on the line or the last statement on a multistatement line A 42 Compile Time Error Messages INCDIRSYN INCLUDE directive syntax error Explanation ERROR A INCLUDE directive either is not followed by a quoted string or incorrectly uses the FROM CDD or FROM LIBRARY clause User Action Supply either a quoted string or the correct syntax for the FROM CDD or FROM LIBRARY clause INCFUNUSA inconsistent function usage for function lt name gt Explanation ERROR The parameter list in a DEF function invocation contains a string where the function expected a number or vice versa This message is issued only when the invocation occurs before the DEF statement in the program User Action Supply a correct parameter in the function invocation or correct the parameter list in the DEF INCRMSERR INCLUDE directive RMS error number lt number gt Explanation ERROR A INCLUDE directive caused an
350. etting the File Position 0 00 eee eee 13 1 13 1 13 2 13 2 13 2 13 3 13 3 13 3 13 4 13 4 13 5 13 6 13 6 13 7 13 7 13 9 13 11 13 11 13 14 13 14 13 16 13 19 13 21 13 21 13 23 13 25 13 27 13 29 13 29 13 6 13 13 6 14 13 6 15 13 6 16 13 7 13 7 1 13 7 2 13 7 3 13 8 13 8 1 13 8 2 13 8 3 13 8 4 13 8 5 13 8 6 13 8 7 13 8 8 13 8 9 13 8 10 13 8 11 13 8 12 Truncating Files Renaming Files Closing Files and Ending NO 0000005 Deleting Files File Related Functions 0 0 00 ce eee eee eee eee FSP Function RECOUNT Function 0 0 0 0 0 cece eee eens STATUS VMSSTATUS and RMSSTATUS Functions OPEN Statement Options 0 0 0 ee ees BUCKETSIZE Clause 0 0 ccc eee eee BUFFER Clause CONNECT Clause 0 0 00 ccc ec ee eee CONTIGUOUS Clause 0 0 0 0 eee DEFAULTNAME Clause 0 0 0 e eee EXTENDSIZE Clause 0 0 000 ce cece ee eee FILESIZE Clatise ss cisco sa wate ens erat glen td ete te ie wee as We Nhe a NOSPAN Clause RECORDTYPE Clause 0 0 00 cc cece eee eee TEMPORARY Clause 0 0 00 eect eae USEROPEN Clause 00 c cece cee eee USEN WINDOWSIZE Clause 0 0 0 0 cece ee eens 14 Formatting Output with the PRINT USING Statement Overview of the PRINT USING Statement Using Format Strings 0 0 ccc ees 14 1 14 2 14 3 14 3 1
351. eturn the VMS condition code that caused the error FIEOVEBUF FIELD overflows buffer ERR 63 Explanation A FIELD statement attempts to access more data than exists in the specified buffer User Action Change the FIELD statement to match the buffer s size or increase the buffer s size B 8 Run Time Messages FILACPFAI FILE ACP failure ERR 252 Explanation The operating system s file handler reported an error to RMS User Action See the VMS I O User s Reference Volume or the OpenVMS Record Management Services Reference Manual FILATTNOT File attributes not matched ERR 160 Explanation The following attributes in the OPEN statement do not match the corresponding attributes of the target file e ORGANIZATION e BUCKETSIZE e BLOCKSIZE e Key number size position or attributes CHANGES and DUPLICATES e Record format User Action Change the OPEN statement attributes to match those of the file or remove the clause FILEXPDAT File expiration date not yet reached ERR 174 Explanation The program attempted to delete a file before the file s expiration date was reached User Action Change the file s expiration date FILIS_LOC File is locked ERR 138 Explanation The program does not allow shared access and attempts to access a file that has been locked by another user or by the system User Action Change the OPEN statement to allow shared access or wait until the file is released by other
352. eyword or contains an illegal character User Action Change the invalid field name CDDBITFLD field lt field name gt from CDD Repository has bit offset or length Explanation ERROR A CDD Repository field does not start on a byte boundary User Action Change the bit field in CDD Repository to have a length that is a multiple of 8 bits CDDCOLMAJ lt array name gt from CDD Repository is a column major array Explanation ERROR An array specified in a CDD Repository definition is column major rather than row major Thus it is incompatible with HP BASIC arrays User Action Change the CDD Repository definition to be a row major array CDDDIGERR decimal digits of lt VALUE gt in CDD Repository out of range for lt field name gt Explanation ERROR A packed numeric CDD Repository definition specifies more than 31 digits User Action Reduce the number of digits specified in the CDD Repository definition CDDDIMNOT RECORD cannot be dimensioned Explanation ERROR A CDD Repository definition is itself an array This is incompatible with HP BASIC RECORDs which can contain arrays but cannot be arrays User Action None You cannot access CDD Repository definitions that are arrays A 12 Compile Time Error Messages CDDDUPREC RECORD lt name gt from CDD Repository has duplicate name Explanation ERROR The CDD Repository record name conflicts with a previous RECORD name The previous RECORD name may be a sta
353. f the following statements STOP END 9 18 Program Control The STOP statement does not close files It can appear anywhere in a program The END statement closes files and must be the last statement in a main program 9 7 1 SLEEP Statement The SLEEP statement suspends program execution for a specified number of seconds The following program waits two minutes 120 seconds after receiving the input string and then prints it INPUT Type a string of characters C SLEEP 120 PRINT C END The SLEEP statement is useful if you have a program that depends on another program for data Instead of constantly checking for a condition the SLEEP statement lets you check the condition at specified intervals 9 7 2 WAIT Statement You use the WAIT statement only with terminal input statements such as INPUT INPUT LINE and LINPUT For example the following program prompts for input then waits 30 seconds for your response If the program does not receive input in the specified time HP BASIC signals Keyboard wait exhausted ERR 15 and exits the program WAIT 30 INPUT You have 30 seconds to type your password PSWS END The WAIT statement affects all subsequent INPUT INPUT LINE LINPUT MAT INPUT and MAT LINPUT statements To disable a previously specified WAIT statement use WAIT 0 In the following example the first WAIT statement causes the first INPUT statement to wait 30 seconds for a response The WAIT 0 statem
354. f typing the text directly on the command line you can also specify a file specification that contains the history entry Using CDD Repository with BASIC 21 11 When you specify AUDIT a history list entry is created for each compiled module entity that the compilation creates In addition the compilation will add a history list entry to each data definition that your program extracts with the ZINCLUDE FROM CDD directive You can display history list information using the CDO utility For example CDO gt SHOW GENERIC CDDSCOMPILED MODULE EXAMPLE1 AUDIT Definition of EXAMPLEl Type CDDSCOMPILED MODULE History entered by SMITH SMITH using BASIC Vn n to CREATE definition on 25 APR 1989 13 04 01 48 Explanation History text goes here 21 6 CDD Repository Arrays CDD Repository supports the following arrays e Multidimensional arrays the ARRAY clause e One dimensional fixed length arrays the OCCURS clause or ARRAY clause e One dimensional variable length arrays the OCCURS DEPENDING ON clause note that HP BASIC does not support this clause Arrays are valid for any CDD Repository field HP BASIC does not support dimensions on a RECORD statement therefore you cannot declare an entire RECORD statement as an array However you can dimension an instance of the record The following is an example of a CDDL data definition containing arrays and the corresponding HP BASIC RECORD statement CDDL Definit
355. f you want to specify lower bounds for your array subscripts you must declare the array explicitly When you declare an array explicitly the value that you give for the upper bound determines the maximum subscript value in that dimension If you specify a lower bound then that is the minimum subscript value in that dimension If you do not specify a lower bound BASIC sets the lower bound in that dimension to zero You can specify bounds as either positive or negative values However the lower bound of each dimension must always be less than or equal to the upper bound for that dimension You can use MAT statements to create and manipulate arrays however MAT statements are valid only on arrays of one or two dimensions In addition the lower bounds of all dimensions in an array referenced in a MAT statement must be zero 6 2 Creating Arrays Explicitly You can create arrays explicitly with four BASIC statements DECLARE DIMENSION COMMON and MAP In addition you can declare arrays as components of a record data type See Chapter 8 for more information about records Normally you use the DECLARE statement to create arrays However you might want to create the array with another BASIC statement as follows e Use the DIM statement to create virtual arrays and arrays that can be redimensioned at run time e Use the COMMON statement to create arrays that can be shared among program modules or to create arrays of fixed length strin
356. f your routine contains any of the following elements the compiler provides an informational diagnostic and emits calls to the RTL initialization and close down routines CHANGE statements DEF statements Dynamic string variables Executable DIM statements EXTERNAL string functions MAT statements MOVE statements for an entire array ON ERROR statements READ statements REMAP statements RESUME statements WHEN blocks String concatenation Built in string functions Virtual arrays 2 30 Developing HP BASIC Programs Routines using OPTION INACTIVE SETUP cannot perform I O and have no error handling capabilities If an error occurs in such a routine the error is resignaled to the calling routine Using OPTION INACTIVE SETUP instructs the compiler not to emit code to initialize local variables This also improves run time performance but impacts routines that rely upon the automatic initialization of local variables CONTINUE without a target and RETRY can limit optimizations within the scope of the WHEN blocks associated with the handler that contains these statements This impact can be significant if the handler is associated with a large WHEN block The code within the associated WHEN blocks will be minimally optimized Developing HP BASIC Programs 2 31 3 Using the OpenVMS Debugger with BASIC This chapter discusses OpenVMS Debugger information that is specific to the BASIC language For more information about the OpenVMS
357. fferent record components overlay the same record field in much the same way that multiple maps can overlay the same storage Such an overlay is called a RECORD variant You use the keywords VARIANT and CASE to set up RECORD variants The following example creates a RECORD template for any three kinds of boats an Creating and Using Data Structures 8 5 RECORD Boat STRING Make STRING Model STRING Type of boat 1 10 This field contains the value S P or C Value S causes the record instance to be interpreted as describing a sailboat value P as describing a powerboat and value C as describing a canoe VARIANT CASE Sailboats STRING Rig 20 CASE Powerboats WORD Horsepower CASE Canoes WORD Length WORD Weight END VARIANT END RECORD The SELECT CASE statement allows you to access one of several possible RECORD variants in a particular RECORD instance A RECORD component outside the overlaid fields usually determines which RECORD variant is being used in a particular reference in this case the determining RECORD component is Type_of_boat You can use this component in the SELECT expression Declarations DECLARE Boat My boat Main program logic starts here Input_boat_information INPUT Make of boat My boat Make INPUT Model My boat Model PRINT Type of boat S Sailboat P Powerboat C Canoe INPUT My boat Type of boat SELECT My boat Type of boat CASE S INPU
358. for array elements 6 10 string literals 5 8 with comma 5 9 with semicolon 5 10 PRINT USING statement 14 1 to 14 17 Print zones 5 9 to 5 11 Priorities of handlers 15 18 Index 12 Procedure call 19 6 PROD function 10 13 precision of 10 11 significant digits 10 10 Program control 9 1 to 9 20 Programs comments 4 5 controlling 9 1 to 9 20 developing 2 1 to 2 31 documenting 4 5 naming 4 4 Program segmentation 12 1 to 12 11 PROGRAM statement 4 4 12 10 to 12 11 identifiers 4 4 12 10 Prompt enabling and disabling 5 4 Protected regions 15 2 15 3 nested 15 10 to 15 11 PUT statement 13 19 to 13 21 18 4 current and next record pointers after 13 19 sequential 13 19 writing data 18 11 writing records with 18 9 Q Qualifiers declining 2 20 Qualifiers on BASIC command line 2 29 QUO function precision of 10 11 significant digits 10 10 R RANDOMIZE statement 10 5 Random number generators 10 5 changing seed 10 5 selecting range 10 6 RCTRLC function 10 16 15 18 READ statement 5 6 to 5 7 REAL data type 4 7 Real number format DOUBLE floating point 17 4 GFLOAT floating point 17 6 SINGLE floating point 17 3 REAL_SIZE qualifier 2 14 Record buffers 13 6 accessing with multiple maps 7 9 dynamic 13 6 static 13 6 RECORD components 8 2 accessing 8 8 to 8 13 fully qualified 8 9 grouping 8 5 referencing 8 2 8 9 Record File Address 1
359. g with an underscore must have the underscore dropped Known instances include _DXmPrintFormatStruct _DXmPrintOptionMenuStruct _MOTIF_BINDINGS _MOTIF_WM_FRAME _MOTIF_WM_HINTS _MOTIF_WM_INFO _MOTIF_WM_MENU _MOTIF_WM_MESSAGES _MOTIF_WM_OFFSET _MWM_HINTS _MWM_INFO _XA_MWM_MESSAGES _XmSDEFAULT_BACKGROUND _XmSDEFAULT_FONT _XmSecondaryResuourceDataRec _XmTraverseObscuredCallbackStru _XtCheckSubclassFlag _XtIsSubclassOf e The following list of identifiers are used either as both a data type and a field name or as a BASIC keyword They cannot be used as is but must have the suffix _D appended when used as a data type and the suffix _F appended when used as a field name Be Be Be Bt Be bt bt tt pe dimension display font name pixel screen size status substitution 22 2 Using DECwindows Motif Bindings with BASIC time value window The DECW MOTIF BAS Motif bindings file includes the file DECW MOTIF_ DEFS BAS which contains data type aliases This makes separate compilation of Motif application subroutines simpler To separately compile a Motif application routine add both of the following e INCLUDE DECW MOTIF_DEFS BAS before the subroutine statement e INCLUDE DECW MOTIFBAS after it 22 3 DECwindows Motif Programming Examples Using BASIC DECW EXAMPLES contains two examples of DECwindows Motif applications in BASIC BASIC HELLOMOTIF BAS and BASIC MOTIFBURGER BAS SYS LIBRARY DECW MOTIEF BAS which contains the D
360. ge text with the lexical function FSMESSAGE at DCL level as shown in the following example PROGRAM Venture DECLARE INTEGER exit status amp REAL capital EXTERNAL LONG CONSTANT SS BADPARAM EXTERNAL SUB play safe INTEGER amp minor risk INTEGER major risk INTEGER Exit status 1 SET NO PROMPT How much INPUT Enter the amount of your free capital capital SELECT capital CASE 0 exit status SSS BADPARAM EXIT PROGRAM exit status CASE lt 5000 CALL play_safe capital CASE lt 15000 CALL minor_risk capital CASE lt 50000 CALL major risk capital CASE ELSE PRINT I can t cope with that amount try again END SELECT GOTO How_much END PROGRAM exit status 12 10 Program Segmentation After program execution you can examine the status of the program at DCL level SHOW SYMBOL SSTATUS STATUS X10 error text FSMESSAGE X10 SHOW SYMBOL error text ERROR_TEXT SYSTEM W BADPARAM bad parameter value The PROGRAM statement is always optional EXIT PROGRAM and END PROGRAM are legal without a matching PROGRAM statement Without a PROGRAM statement these statements still exit the main compilation unit The EXIT PROGRAM and END PROGRAM statements are not valid within SUB FUNCTION or PICTURE subprograms Program Segmentation 12 11 13 File Input and Output This chapter explains BASIC file organizations and record operations that are implemented through OpenVMS Record Management Service
361. ger command 3 2 SET NO PROMPT statement disabling the prompt 5 5 SET TRACE debugger command 3 9 SET VARIANT command 16 10 SET NO PROMPT statement 5 4 to 5 5 6 15 Severe errors 15 1 Shareable images 20 1 to 20 6 accessing 20 4 20 5 benefits of 20 4 Index 13 Shareable images cont d contents of 20 1 creating 20 4 installed 20 1 SHARE qualifier 3 9 SHOW CALLS debugger command 3 6 SHOW qualifier 2 16 SILENT qualifier 3 10 SIN function 10 3 Single tape file example of creating 13 41 Source display 3 2 3 3 not available 3 4 TYPE debugger command 3 2 SPACE function string function 11 16 SQR function 10 4 Square root SQR function 10 4 Statement modifiers 9 1 to 9 3 FOR 9 1 IF 9 1 UNLESS 9 1 UNTIL 9 1 WHILE 9 1 Static storage 4 8 allocating 7 4 dynamic mapping 7 13 Status on exit 12 10 STATUS 12 10 STATUS function 13 33 to 13 34 STEP clause 9 3 STEP debugger command 3 5 Storage dynamic 4 8 redefining 7 12 static 4 8 Stream record format 13 2 String dynamic 11 1 fixed length 11 1 manipulating with multiple maps 7 8 numeric 10 7 variable 4 11 Index 14 String cont d virtual array 11 1 STRING function string function 11 15 String data assigning and justifying 11 5 formatting with PRINT USING statement 14 1 manipulating with MAP statements 11 18 manipulating with string functions 11 9 STRING data type 4 7 String format f
362. ginary part This is shown in the following CDD Repository data definition and corresponding HP BASIC RECORD statement 21 26 Using CDD Repository with BASIC 21 9 4 CDDL Definition define record CDDStop basic complex description is test complex data types complex structure my_s_ complex 1 datatype f floating complex my _d complex 1 datatype d_floating_complex my_g complex 1 datatype g floating complex end complex structure end complex Translated RECORD Statement 1 INCLUDE FROM CDD CDDS TOP BASIC COMPLEX cl test complex data types Cl RECORD COMPLEX UNSPECIFIED Cl GROUP MY S COMPLEX 1 F FLOATING COMPLEX eal SINGLE SINGLE R VALUE Cl SINGLE SINGLE I VALUE Cl END GROUP Cll GROUP MY D COMPLEX 1 D FLOATING COMPLEX Cl DOUBLE DOUBLE R VALUE Cl DOUBLE DOUBLE I VALUE Cl END GROUP Bg Cl GROUP MY G COMPLEX 1 G FLOATING COMPLEX Cl GFLOAT GFLOAT R VALUE 7 T Cl GFLOAT GFLOAT I VALUE Cl END GROUP Cl END RECORD ee ee 1 BASIC I CDDSUBGRO 1 data type in CDD Repository not supported substituted group for COMPLEX MY S COMPLEX 1 BASIC I CDDSUBGRO 1 data type in CDD Repository not supported substituted group for COMPLEX MY D COMPLEX 1 BASIC I CDDSUBGRO 1 data type in CDD Repository not supported substituted group for COMPLEX MY_G COMPLEX 1 Decimal String Data Types CDD Repository supports the following forms of decimal string data types e LEFT OVERPUNCHED NUM
363. given dimension For more information about specifying bounds with the COMMON statement see Chapter 6 and the HP BASIC for OpenVMS Reference Manual Data Definition 7 5 7 7 2 MAP Statement 7 7 2 1 The MAP statement like the COMMON statement creates a named area of static storage However if a program module contains multiple maps with the same name the maps are overlaid on the same area of storage rather than being concatenated When used with the MAP clause of the OPEN statement the storage allocated by the MAP statement becomes the record buffer for that file Variables in the MAP statement correspond to fields in the file s records A map item can be one of the following e Numeric variable e Numeric array e Fixed length string variable e Array of fixed length strings e RECORD instance e FILL item When you explicitly declare an array HP BASIC allows you to specify both upper and lower bound values The value you supply as the upper bound determines the maximum subscript value for a given dimension and the value you supply for the lower bound determines the minimum subscript value for a given dimension For more information about specifying bounds with the MAP statement see Chapter 6 and the HP BASIC for OpenVMS Reference Manual Single Maps You associate a map with a record buffer by referencing the map in the OPEN statement The MAP statement must appear before any reference to map variables Changes to
364. gn The representation for the digits or signs is shown in the following table 17 8 Data Representation Digit or Sign Decimal Hexadecimal 0 0 0 1 1 1 2 2 2 3 3 3 4 4 4 5 5 5 6 6 6 7 7 7 8 8 8 9 9 9 10 12 14 or 15 A C E or F 11 or 13 BorD Despite the options the preferred sign representation is 12 for positive and 13 for negative The length L is the number of digits in the packed decimal string not counting the sign and must be in the range 1 to 31 If the number of digits is odd the digits and the sign fit into L 2 1 bytes when the number of digits is even an extra 0 digit must appear in the high nibble bits 7 to 4 of the first byte The address A of the string specifies the byte of the string containing the most significant digit in its high nibble Digits of decreasing significance are assigned to increasing byte addresses and from high nibble to low nibble within a byte Note that the decimal point is specified by the descriptor for the packed decimal string See Section 17 6 for more information about packed decimal string descriptions 17 4 String and Array Descriptor Format A descriptor is an OpenVMS data structure that describes how to access data in memory A descriptor can also pass information about a paramater with that parameter The following sections describe the formats for fixed length and dynamic string descriptors Data Representation 17 9 17 4 1 17 4 2 Fi
365. gn the address to the variable or array element You can do this either with the GETRFA function or by reading a file of RFAs generated by previous GETRFA functions or by the VMS Sort Utility 3 Specify the variable in the RFA clause of a GET or FIND statement The GETRFA function returns the RFA of the last record accessed on a channel Therefore you must access a record in the file with a GET FIND or PUT statement before using the GETRFA function Otherwise GETRFA returns a zero which is an invalid RFA The following example declares an array of type RFA containing 100 elements After each PUT operation the RFA of the record is assigned to an element of the array Once the RFA information is assigned to a program variable or array element you can use the RFA clause on a GET or FIND statement to retrieve the record DECLARE RFA R array 1 TO 100 DECLARE LONG I MAP XYZ STRING A 80 OPEN TEST DAT FOR OUTPUT AS FILE 1 amp SEQUENTIAL MAP XYZ FOR I 1 TO 100 PUT 1 R_array I GETRFA 1 NEXT I You can use the RFA clause on GET or FIND statements for any file organization the only restriction is that the file must reside on a disk that is accessible to the node that is executing the program An RFA value is only valid for the life of a specific version of a file If a new version of a file is created the RFA values might change If you attempt to access a record with an invalid RFA value HP BASIC signals a run
366. gned octaword end basicint structure end bigintegers Translated RECORD Statement 1 SINCLUDE FROM CDD CDDSTOP BASIC BIGINTEGERS CI Test of quadword and octaword integer data types Cl RECORD BASICINT UNSPECIFIED Cl QUAD MY QUAD SIGNED QUADWORD Cl GROUP MY OCTA SIGNED OCTAWORD Cl STRING STRING VALUE 16 Cl END GROUP Cl END RECORD BASIC I CDDSUBGRO data type in CDD Repository not supported substituted group for BASICINT MY_OCTA CDD Repository supports the SCALE keyword to specify an implied exponent in integer data types and the BASE keyword supported in CDDL only to specify that the scale for a fixed point field is to be interpreted in a numeric base other than 10 HP BASIC does not support these integer attributes Therefore HP BASIC signals the informational message CDD Repository specifies SCALE for lt name gt Not supported for fixed point fields containing 21 24 Using CDD Repository with BASIC a SCALE specification and the error message CDD Repository attributes for lt name gt are other than base 10 for fixed point fields specifying a base other than 10 For example CDDL Definition define record CDDStop basic funnyintegers description is Test of quadword and octaword integer data types basicint structure my byte datatype is signed byte scale 2 my long datatype is signed longword base 8 end basicint structure end funnyintegers Translated RECORD Statement ZINCLUDE FROM
367. gram each range of values is tested before it overlaps in the next range Because the 9 12 Program Control compiler executes the first matching CASE statement the overlapping values do not matter DECLARE REAL Stock_change INPUT Please enter stock price change Stock_change SELECT Stock_change CASE lt 0 5 PRINT Don t sell yet CASE lt 1 0 PRINT Sell today CASE ELSE PRINT Sell NOW END SELECT END Output Please enter stock price change 2 1 Sell NOW If no match is found for any of the specified cases and there is no CASE ELSE block HP BASIC transfers control to the statement following END SELECT without executing any of the statements in the SELECT block SELECT CASE lets you use run time expressions for both SELECT expressions and CASE values The following example uses HP BASIC built in string functions to examine command input This program is a skeleton command processor It recognizes three VAX BASIC Environment commands l l SAVE SCRATCH OLD DECLARE INTEGER CONSTANT True 1 DECLARE INTEGER CONSTANT False 0 DECLARE STRING CONSTANT Null_input This is the null string DECLARE STRING Command Main program logic starts here Command_loop WHILE True This loop executes until the user types only a carriage return in response to the prompt Program Control 9 13 PRINT PRINT Please enter a command uppercase only PRINT Type a carriage return when f
368. gram compiled with the ANSI_ STANDARD qualifier contains a string array User Action Remove the string array STRCONEXP string constant expression is too long Explanation ERROR The program contains a DECLARE STRING CONSTANT statement where the value assigned to the constant exceeds the maximum number of characters allowed for string constant expressions The maximum length of a string constant expression at compile time is 498 characters User Action Change the string constant to a string variable and assign the string expression to the variable at run time STRCONREQ string constant required Explanation ERROR The program contains a numeric expression in a context that requires a string expression for example DECLARE STRING CONSTANT ABC 123 User Action Supply a string literal or a named string constant STRDEFNOT string DEF not ANSI Explanation INFORMATION A program compiled with the ANSI_ STANDARD qualifier contains a string DEF User Action Remove the string DEF A 80 Compile Time Error Messages STRLENANY string length not allowed on ANY Explanation ERROR An ANY parameter specifies a string length in an EXTERNAL statement This is not allowed because ANY implies that you can use any data type not specifically a string data type User Action Remove the string length specification from the ANY clause STRIS_NEE string expression is required Explanation ERROR The program contains a numer
369. gs 6 2 Arrays e Use the MAP statement to create an array and associate it with a record buffer or to overlay the storage for an array thus accessing the same storage in different ways When you create an array the bounds you specify determine the array s size The maximum value allowed for a bound can be as large as 2147483467 however this number is actually limited by the amount of virtual storage available to you Very large arrays and arrays with many dimensions can cause fatal errors at both compile time and run time The following restrictions apply to arrays e When referencing an array you must use the same number of subscripts as was specified when the array was created e You can use identical names for a simple variable and an array for example A and A 5 5 However this is not a recommended programming practice If you use identical names for arrays with a different number of subscripts for example A 5 and A 10 10 BASIC prints the error Inconsistent subscript usage at compile time e Ifsubscript checking is enabled HP BASIC signals the error Subscript out of range ERR 55 if you reference an array element whose subscripts are one of the following Greater than the current upper bound of the array Less than the current lower bound of the array Less than zero where no lower bound was specified 6 2 1 Creating Arrays with the DECLARE Statement The DECLARE statement creates and
370. h the redundant most significant fraction bit not represented unless the exponent is 0 If the exponent is 0 a nonzero fraction represents an unnormalized 112 bit fraction Data Representation 17 7 An exponent value of 0 together with a fraction value of 0 and a sign bit of 0 indicates that the X_floating number value is 0 Exponent values from 1 to 32766 indicate true binary exponents from 16383 to 16383 The value of an X_floating number is in the approximate range 3 362 1074982 to 1 189 104982 the precision is approximately one part in 2 approximately 33 decimal digits Note that X_floating format provides approximately the same range and precision as H_floating format Figure 17 10 XFLOAT Floating Point Number Format 127 126 112 111 0 S EXPONENT FRACTION A N ZK 7420A GE 17 3 Packed Decimal Number Format The DECIMAL data type is useful for storing numbers with a fixed decimal point DECIMAL numbers are stored as a precise representation of the value stored within the constraints of the specified number of fractional digits A packed decimal string is a contiguous sequence of bytes in memory The address A and length L are sufficient to specify a packed decimal string but note that L is the number of digits not bytes in the string Each byte of a packed decimal string is divided into two 4 bit fields nibbles each of which must contain decimal digits except the low nibble of the last byte which must contain a si
371. he following example first assigns a value of 5 to the variable A then transfers control to the subroutine labeled Times_two This subroutine replaces the value of A with A multiplied by 2 The subroutine s RETURN statement transfers control to the first PRINT statement which displays the changed value The program calls the subroutine two more times with different values for A Each time the RETURN transfers control to the statement immediately following the corresponding GOSUB 9 16 Program Control A 5 GOSUB Times two PRINT A A 15 GOSUB Times two PRINT A A 25 GOSUB Times two PRINT A GOTO Done Times two This is the subroutine entry point A A 2 RETURN Done END Output 10 30 50 Note that HP BASIC signals RETURN without GOSUB if it encounters a RETURN statement without first having encountered a GOSUB or ON GOSUB statement 9 6 2 ON GOSUB OTHERWISE Statement The ON GOSUB OTHERWISE statement transfers control to one of several target subroutines depending on the value of a numeric expression A RETURN statement returns control to the first statement after the calling ON GOSUB A subroutine can contain more than one RETURN statement so that you can return control conditionally depending on a specified condition HP BASIC tests the value of the integer expression If the value is 1 control transfers to the first line number or label in the list if the value is 2 control passes to the secon
372. he following is an example of a loop created using the FOR modifier A A 1 FOR I 1 TO 10 9 1 4 UNTIL Modifier The UNTIL modifier like the FOR modifier creates a single line loop However instead of using a formal loop variable you specify the terminating condition with a conditional expression The modified statement executes repeatedly as long as the condition is false For example B B 1 UNTIL A B lt 0 0001 9 1 5 WHILE Modifier The WHILE modifier repeats a statement as long as a conditional expression is true Like the UNTIL and FOR modifiers the WHILE modifier lets you create single line loops In the following example HP BASIC replaces the value of A with A 2 as long as the absolute value of A is greater than one tenth Note that you can inadvertently create an infinite loop if the terminating condition is never reached A A 2 WHILE ABS A gt 0 1 9 2 Program Control 9 1 6 Nesting Modifiers If you append more than one modifier to a statement you are nesting modifiers HP BASIC evaluates nested modifiers from right to left If the test of the rightmost modifier fails control passes to the next statement not to the preceding modifier on the same line In the following example HP BASIC first tests the rightmost modifier of the first PRINT statement Because this condition is false HP BASIC executes the following PRINT statement and tests the rightmost modifier Because this condition is met HP BA
373. he number of elements specified For example an array with an upper bound of 10 and no specified lower bound has 11 elements 0 to 10 inclusive The array My_array 3 3 has 16 elements 0 to 3 in each dimension or 42 BASIC also lets you specify a lower bound for any or all dimensions in an array unless the array is a virtual array By specifying lower and upper bounds for arrays you can make your array subscripts meaningful For example the following array contains sales information for the years 1990 to 1999 DECLARE REAL Sales data 1990 TO 1999 To refer to an element in the array Sales_data you need only specify the year you are interested in For example to print the information for the year 1999 you would enter PRINT Sales data 1999 Arrays 6 1 You can create arrays either implicitly or explicitly You implicitly create arrays having any number of dimensions by referencing an element of the array If you implicitly create an array BASIC sets the upper bound to 10 and the lower bound to zero Therefore any array that you create implicitly contains 11 elements in each dimension The following example refers to the array Student_grades If the array has not been previously declared BASIC will create a one dimensional array with that name The array contains 11 elements Student_grades 8 B You create arrays explicitly by declaring them in a DIM DECLARE COMMON or MAP statement or record declaration Note that i
374. he values and the information they return are as follows Value Information Returned 0 A N e Returns the number of seconds elapsed since midnight Returns the current job s CPU time in tenths of a second Returns the current job s connect time in minutes Returns zero Returns zero All other arguments to TIME are undefined and cause HP BASIC to signal Not implemented ERR 250 10 1 6 Terminal Control Functions HP BASIC provides several terminal control functions These functions let you e Enable and disable Ctrl C trapping e Enable and disable terminal echoing e Read a single keystroke from a terminal Functions 10 15 10 1 6 1 10 1 6 2 CTRLC and RCTRLC Functions The CTRLC function enables Ctrl C trapping and the RCTRLC function disables Ctrl C trapping When Ctrl C trapping is enabled control is transferred to the program s error handler when Ctrl C is detected at the controlling terminal Ctrl C trapping is asynchronous The trap can occur in the middle of an executing statement and a statement so interrupted leaves variables in an undefined state For example the statement A ABC if interrupted by Ctrl C could leave the variable A partially set to ABC and partially left with its previous contents For example if you type Ctrl C to the following program when Ctrl C trapping is enabled an ABORT message prints to the file open on channel 1 This lets you
375. hey provide the same capabilities See Section 13 5 for more information about accessing the individual records in a disk block 13 4 File Input and Output 13 3 Record Access and Record Context Record access modes determine the order in which your program retrieves or stores records in a file They determine the record context the current record and the next record to be processed When your program successfully executes any record operation the current record and next record pointers can change If a record operation is unsuccessful these pointers do not change The record access modes valid for RMS are e Sequential access valid on any file organization e Random by record number access valid on sequential fixed and all relative files e Random by key access valid on indexed files e Random by RFA Record File Address access valid on any RMS file located on disk With sequential access the next record is the next logical record in the file In the case of relative files the next logical record is the next existing record deleted or never written records are skipped In the case of indexed files the next logical record is the record with the next ascending or descending value in the current key of reference depending on that key s collating sequence You can therefore access relative or indexed files sequentially by not specifying a relative record number or key value You can also access sequential fixed length and re
376. hold the specified string length Using CDD Repository with BASIC 21 21 Example 21 2 Translated RECORD Statement 1 SINCLUDE FROM CDD CDDSTOP BASIC STRINGS Cl test Cl RECORD BASICSTRINGS UNSPECIFIED Cl STRING ABC 10 TEXT Cl GROUP XYZ VARYING STRING Cl WORD WORD VALUE Cl STRING STRING VALUE 16 Cl END GROUP z Cl END RECORD Sisal dea bids aR AA 1 SBASIC I CDD SUBGRO 1 data type in CDD Repository not supported substituted group for BASICSTRINGS XYZ Note The count field preceding the VARYING STRING is actually an UNSIGNED WORD Therefore the count field of a VARYING STRING whose length is greater than 32 767 is interpreted by HP BASIC as a negative number In the previous example the group name XYZ is the same name as a CDD Repository field Therefore HP BASIC supplies an additional name for the RECORD components The supplied names are WORD_VALUE and STRING_VALUE For example the following program statement creates an instance of the record BASICSTRINGS called MY_REC 100 MAP TEST BASICSTRINGS MY REC The names you use to reference these components in HP BASIC are MY_ REC XYZ WORD_VALUE and MY_REC XYZ STRING_VALUE 21 9 2 Integer Data Types CDD Repository refers to integer data types as fixed point data types CDD Repository supports BYTE WORD LONGWORD QUADWORD and OCTAWORD integer data types Each of these data types can have the following additional attributes SIGNED UNSIGN
377. i 11 viii 10 1 3 String Numeric Functions 10 1 3 1 FORMATS Function 10 1 3 2 NUM and NUM1 Functions 10 1 3 3 VAL and VAL Functions 10 1 4 String Arithmetic Functions 10 1 4 1 SUM and DIF Functions 10 1 4 2 QUO PLACE and PROD Functions 10 1 5 Date and Time Functions 10 1 5 1 DATE Function 10 1 5 2 DATE4 Function 10 1 5 3 TIME Function 10 1 5 4 TIME Function 10 1 6 Terminal Control Functions 10 1 6 1 CTRLC and RCTRLC Functions 10 1 6 2 ECHO and NOECHO Functions 10 1 6 3 INKEY Function 10 2 User Defined Functions 10 2 1 Single Line DEF Functions 10 2 2 Multiline DEF Functions String Handling 11 1 Overview of Strings i204 ba 444054 Pe bhEE Ee eG SLOSS FERES 11 2 Using Dynamic Strings 0 0 eee 11 3 Using Fixed Length Strings 0 0 0 cece eee 11 4 Using String Virtual Arrays 0 20 0 0 11 5 Assigning String Data 0 0 eee eee 11 5 1 LET Statement 0 0 ce eee 11 5 2 LSET Statement 6 s3 6 S e nuiee d terts ed oY ae wwe wR ae 11 5 3 RSET Statement occnee rensie ek LEPE ER Geo ekes 11 5 4 MID Assignment Statement 00 000 eee eee 11 6 Manipulating String Data with String Functions 11 6 1 LEN Funcion
378. iated with INVENTORY into the object module INVENTORY OBJ These records allow you to use the names of variables and other symbols declared in INVENTORY in debugger commands If your program has several compilation units you must compile each unit that you want to debug with the DEBUG qualifier The DEBUG qualifier with the LINK command instructs the linker to include all symbol information that is contained in INVENTORY OBJ in the executable image The qualifier also causes the OpenVMS image activator to start the debugger at run time If your program has several object modules you might need to specify other modules in the LINK command 3 3 Viewing Your Source Code The debugger provides two methods for viewing source code noscreen mode and screen mode By default when you invoke the debugger you are in noscreen mode but you might find that it is easier to view your source code with screen mode Both modes are described in the following sections 3 3 1 Noscreen Mode Noscreen mode is the default line oriented mode of displaying input and output To get into noscreen mode from screen mode enter SET MODE NOSCREEN See the sample debugging session in Section 3 7 for a demonstration of noscreen mode In noscreen mode you can use the TYPE command to display one or more source lines For example the following command displays line 3 of the module that is currently executing DBG gt TYPE 3 3 EXTERNAL SUB TRIPLE amp DBG gt
379. ic expression where a string expression is needed for example NAME 1 AS ABC DAT User Action Supply a string expression STRLENDYN string length not allowed on MAP DYNAMIC variable Explanation ERROR A string variable in a MAP DYNAMIC statement specifies a string length User Action Remove the string length All string variables named in a MAP DYNAMIC statement have a length of zero until a REMAP statement executes STRLENINC virtual array string lt name gt length increased from lt n gt to lt m gt Explanation WARNING In a string virtual array DIM statement the specified string length is not a power of two User Action None HP BASIC increases the string length to the next higher power of two STRLENMUS string length specification for lt name gt must be numeric Explanation ERROR The length specification for a fixed length string is nonnumeric for example COMMON A ABC User Action Supply a numeric length specification STRLENNOT string length not allowed on numeric variable lt name gt Explanation ERROR The declaration for a numeric variable contains a string length specification User Action Remove the string length specification STRLENTRU virtual array string lt name gt length truncated from lt n gt to lt m gt Explanation WARNING A string virtual array specifies a string length greater than 512 HP BASIC truncates the length specification to 512 User Action
380. ics of the file to RMS and verifies the result Opening a file with the specification FOR INPUT specifies that you want to use an existing file Opening a file with the specification FOR OUTPUT indicates that you want to create a new file If you do not specify FOR INPUT or FOR OUTPUT BASIC tries to open an existing file If no such file exists a new file is created File Input and Output 13 11 Clauses to the OPEN statement allow you to specify the characteristics of a file All OPEN statement clauses concerning file or record format are optional when you open an existing file those attributes that are not specified default to the attributes of the existing file When you open an existing file you must specify the file name channel number and unless the file is a terminal format file an organization clause If you do not know the organization of the file you want to open you can specify ORGANIZATION UNDEFINED If you specify ORGANIZATION UNDEFINED also specify RECORDTYPE ANY If you do not specify a map in the OPEN statement the size of your program s record buffer is determined by the OPEN statement RECORDSIZE clause or by the record size associated with the file If you specify both a MAP clause and a RECORDSIZE clause in the OPEN statement the specified record size overrides the size specified by the MAP clause The following statement opens a new sequential file of stream format records OPEN TEST DAT FOR OUTPUT AS FILE 1
381. ides a special set of MAT statements for array computations These statements enable you to add subtract and multiply matrices and to assign values to elements Note that if you specify an array without subscripts for example MAT A the default is two dimensions BASIC also provides matrix functions to transpose and invert matrices and to find the determinant of a matrix you invert Note MAT operators do not operate on elements in row or column zero 6 7 1 Arithmetic Matrix Operations MAT operators perform matrix assignment addition subtraction and multiplication All of these operations use the keyword MAT followed by an expression If the array has not been previously dimensioned these operations create an array The created output array s dimensions depend on the operation performed but must be 10 10 or smaller Note You can use the MAT operators on arrays larger than 10 10 if the input and output arrays are explicitly created or received as a formal parameter 6 7 1 1 Assignment You can assign all values in one array to another array with the MAT statement In the following example each element of new_array is set to the corresponding element in old_array The dimensions of new_array are also redimensioned to the dimensions of o d_array MAT new_array old array Arrays 6 19 6 7 1 2 Addition and Subtraction You can add the elements of two arrays In the following statement
382. ields 14 13 String function EDIT function 11 16 LEN function 11 9 MID function 11 14 POS function 11 10 purposes 11 9 SEG function 11 12 SPACE function 11 16 STRING function 11 15 TRM function 11 16 with the LET statement 11 9 String handling 11 1 to 11 20 Strings printing with PRINT USING statement 14 12 String variables fixed length 11 1 String virtual arrays assigning values 11 5 creating 11 4 Subprograms 12 1 calling from other languages 19 8 compiling 12 7 to 12 8 compiling from a single source file 12 7 compiling from multiple source files 12 7 creating a single object file 12 7 DATA statements in 12 2 handling errors in 15 18 to 15 20 invoking 12 8 to 12 9 passing data to 12 5 READ statements in 12 2 RESTORE statements in 12 2 Subscripted variables 4 10 4 11 SUB subprograms 12 1 to 12 3 Subtraction of matrices 6 20 SUM function precision of 10 11 Symbol record 3 2 Symbolic debugger See Debugger Symbolic definitions 19 17 accessing with INCLUDE directive 19 18 location of 19 18 SYNCHRONOUS_EXCEPTIONS 2 16 SYSTEM qualifier 3 9 System routines arguments of 19 12 calling 19 10 calling as a procedure 19 6 examples of calling 19 19 System Service routines 19 11 System services example of calling 19 19 T TAN function 10 3 Tapes allocating 18 2 setting the density 18 2 Tape unit allocating for device specific I O 18 7 Template
383. ifies both SPAN and NOSPAN User Action Remove one of the clauses SPELL assuming lt item gt intended to be the keyword lt keyword gt Explanation ERROR The program contains a syntax error HP BASIC assumes that a keyword has been misspelled and compilation continues so that other errors can be detected The actual program line remains unchanged and no object file is produced User Action Examine the line carefully to discover the error Change the program line to correct the syntax error SPENUMEXC specified numeric exceeds valid character code Explanation ERROR A quoted literal of type character C contains a value outside the valid range for example 300 C User Action Use a valid ASCII value Compile Time Error Messages A 79 STACKOVF stack frame overflow for variables Explanation ERROR The program requires too much space for dynamic variables User Action Reduce the number of dynamic variables or place some of the variables in a MAP or COMMON STANOTALL statement not allowed within a PICTURE definition Explanation ERROR The statement you specified is not allowed in a PICTURE definition User Action Remove the statement from the PICTURE definition STARISNEE star is needed in DEF not Explanation ERROR The program contains a statement that starts with DEF User Action Change the DEF to DEF STRARRNOT string array not ANSI Explanation INFORMATION A pro
384. iler you use the DCL command BASIC With the BASIC command you can specify command qualifiers The next sections discuss the BASIC command in detail as well as the command qualifiers available 2 1 1 BASIC Command When you compile your source program use the BASIC command which has the following format BASIC qualifier file spec qualifier qualifier Indicates a specific action to be performed by the compiler on all files or specific files listed When a qualifier appears directly after the BASIC command it affects all files listed file spec Indicates the name of the input source file that contains the program or module to be compiled You are not required to specify a file extension the HP BASIC compiler assumes the default file type BAS Developing HP BASIC Programs 2 1 Most of the command qualifiers to the BASIC command affect all files specified in the command line no matter where the qualifiers are placed these are called global qualifiers However the qualifiers LISTING OBJECT DIAGNOSTICS and ANALYSIS_DATA are positional qualifiers that is depending on their position in the command line they can affect all or only some of the specified files The rules for positional qualifiers are as follows e Ifthe positional qualifier is located directly following the command name it affects all the specified files e If the file specifications are separated by commas then any positional qualifier d
385. in effect throughout program execution time When an error occurs in your program HP BASIC diagnoses the error and displays a message telling you the nature and severity of the error There are four severity levels of HP BASIC errors SEVERE ERROR WARNING and INFORMATIONAL The severity of an error determines whether or not the program aborts if the error occurs when default error handling is in effect When default error handling is in effect ERROR and SEVERE errors always terminate program execution but program execution continues when WARNING and INFORMATIONAL errors occur To override the default error handling procedures you can provide your own error handlers as described in the following sections Note that you should not call LIBSESTABLISH from a HP BASIC program as this RTL routine overrides the default error handling procedures and might adversely affect program behavior Only one error can be handled at a time If an error has occurred but has not yet been handled completely that error is said to be pending When an error is pending and a second error occurs program execution always terminates immediately Therefore one of the most important functions of an error handler is to clear the error so that subsequent errors can also be handled Handling Run Time Errors 15 1 If you do not supply your own error handler program control passes to the HP BASIC error handler when an error occurs For example when HP BASIC default
386. included for completeness Table B 2 Errors Not Generated by HP BASIC Number Text 3 Account or device in use 6 Not a valid device 8 Device not available 13 User data error on device 16 Name or account now exists 17 Too many open files on unit 19 Disk block is interlocked 20 Pack ids don t match 21 Disk pack is not mounted 22 Disk pack is locked out 23 Illegal cluster size 24 Disk pack is private 25 Disk pack needs cleaning 26 Fatal disk pack mount error 27 1 O to detached keyboard 30 Device not file structured 32 No buffer space available 33 Odd address trap 34 Reserved instruction trap 36 SP stack overflow 37 Disk error during swap 38 Memory parity or ECC failure 39 Magtape select error 40 Magtape record length error continued on next page Run Time Messages B 37 Table B 2 Cont Errors Not Generated by HP BASIC Number Text 41 44 47 60 62 65 68 70 71 74 75 76 TT 78 79 80 81 82 83 84 85 86 87 90 91 92 93 94 95 96 Non res run time system Matrix or array too big Line too long Integer overflow FOR loop No run time system Illegal MAGTAPE usage unused Statement not found Undefined function called Illegal symbol Illegal verb Illegal expression Illegal mode mixing Illegal IF statement Illegal conditional clause Illegal function name Illegal dummy variable Illegal FN redefinition Illegal line numbe
387. ing example uses the VARIANT directive which returns the value set by the SET VARIANT command or VARIANT qualifier SIF SVARIANT 23 THEN DECLARE LONG int array 100 ELSE DECLARE WORD int array 100 SEND SIF This directive allows for two possibilities If you compile this program with a VARIANT 2 qualifier then BASIC creates an array of longword integers If you compile this program with any other variant value BASIC creates an array of word integers Because IF can appear within a program line you can express the same directive this way DECLARE IF VARIANT 2 THEN LONG ELSE WORD END IF int_array 100 A THEN or ELSE clause can also contain other compiler directives For example the following program creates the lexical constant my_constant and assigns it a value of 8 The IF directive evaluates the conditional expression Y my_constant VARIANT gt 10 If this expression is true BASIC executes the THEN clause aborting the compilation and issuing an error message If the expression is false BASIC prints the specified message and continues to compile your program without aborting the compilation Compiler Directives 16 11 SLET my constant 8 SIF my constant VARIANT gt 10 THEN SABORT Cannot compile with VARIANT gt 2 SELSE SPRINT Successful Compilation SEND IF The compilation listing shows you which clause was actually compiled 16 4 6 DEFINE and UNDEFINE Directives
388. ingle Precision Real Number Format 15 14 76 0 S BINARY NUMBER FRACTION N FRACTION 31 16 ZK 5176 GE DOUBLE Floating Point Number Format D_floating Double precision real number format consists of eight contiguous bytes starting on an arbitrary byte boundary Bits are labeled from the right 0 to 63 as in Figure 17 6 The form of a D_floating number is identical to the F floating form except for an additional 32 low significance fraction bits Within the fraction bits increase in significance from 48 to 63 32 to 47 16 to 31 and 0 to 6 The exponent conventions and approximate range of values are the same for both D_floating and F_floating numbers The precision of a D_floating number is approximately one part in 255 approximately 16 decimal digits 17 4 Data Representation Figure 17 6 Double Precision Real Number Format 15 14 7 6 0 EXPONENT FRACTION 63 48 ZK 5177 GE In Alpha BASIC it is possible to lose three binary digits of precision in arithmetic operations when performing operations on D_floating double precision floating point data For each arithmetic operation the data is converted to G_floating first the operation is performed in G_floating and the result is converted back to D_floating when the operation is complete Note Because most floating point values cannot be represented exactly in binary they are susceptible to rounding 164 BASIC and the Itanium hardware use T_floa
389. inished INPUT Command PRINT SELECT Command CASE Null_input If user types RETURN exit from the loop GOTO Done and end the program The next three cases use the SEG and LEN string functions LEN returns the length of the typed string and SEGS searches the string literals SAVE SCRATCH and OLD for a match up to that length Note that if the user types an S it is interpreted as a SAVE command only because SAVE is the first case tested CASE SEG SAVE 1 LEN Command PRINT That was a SAVE command CASE SEG SCRATCH 1 LEN Command PRINT That was a SCRATCH command CASE SEG OLD 1 LEN Command PRINT That was an OLD command CASE ELSE PRINT Invalid command please try again END SELECT NEXT Done END 9 5 EXIT and ITERATE Statements This section describes the EXIT and ITERATE statements and shows their use with nested control structures The ITERATE and EXIT statements let you explicitly control loop execution These statements can be used to transfer control to the top or bottom of a control structure You can use EXIT to transfer control out of any of these structures e FOR NEXT loops e WHILE NEXT loops e UNTIL NEXT loops e IF THEN ELSE blocks 9 14 Program Control e SELECT CASE blocks e SUB FUNCTION and PICTURE subprograms e DEF functions and programs In the case of control structures EXIT passes control to the first s
390. inning of the string not the starting position of the search For example if you search the string ABCDE for the substring E it does not matter whether you specify a starting position of 1 2 3 4 or 5 HP BASIC still returns the value 5 as the position where the substring was found If the function finds the substring it returns the position of the substring s first character Otherwise it returns zero as in the following example alpha ABCDEFGHIJKLMNOPQRSTUVWXYZ Z DEFG X POS ALPHAS Z 1 PRINT X Q TEST Y POS ALPHAS Q 1 PRINT Y END Output 4 0 If you specify a starting position other than 1 HP BASIC still returns the position of the substring relative to the beginning of the string as shown in the following example 11 10 String Handling alpha ABCDEFGHIJKLMNOPQRSTUVWXYZ Z HIJ PRINT POS ALPHA Z 7 END Output 8 If you know that the substring is not near the strings beginning specifying a starting position greater than one speeds program execution by reducing the number of characters HP BASIC must search You can use the POS function to associate a character string with an integer that you can then use in calculations This technique is called a table look up The following example prompts for a 3 character string changes the string to uppercase letters and searches the table string to find a match The WHILE loop executes indefinitely until a carriage ret
391. ion define record CDD top basic arrayl description is test arrays array 1 structure my byte my string my s real my d real my g real my h real array 0 2 array 0 10 array 0 2 0 4 array 1 3 occurs 4 times occurs 4 times end array 1 structure end arrayl 21 12 Using CDD Repository with BASIC datatype datatype datatype datatype datatype datatype signed byte text size 10 f floating d floating g floating h floating Translated RECORD Statement 1 SINCLUDE FROM CDD CDDSTOP BASIC ARRAY1 Cl test arrays C1 RECORD ARRAY 1 UNSPECIFIED C1 BYTE MY BYTE 0 TO 2 SIGNED BYTE C1 STRING MY STRING O TO 10 10 TEXT Cl SINGLE MY S REAL 0 TO 2 0 TO 4 F FLOATING c1 DOUBLE MY D REAL 1 TO 3 D FLOATING Cl GFLOAT MY G REAL 1 TO 4 G FLOATING C1 HFLOAT MY H REAL 1 TO 4 H FLOATING Cl END RECORD By default arrays in CDD Repository are row major This means that when storage is allocated for the array the rightmost subscript varies fastest All HP BASIC arrays are row major HP BASIC does not support column major arrays If a CDD Repository definition containing a column major array is extracted HP BASIC signals the error lt array name gt from CDD Repository is a column major array By default HP BASIC extracts an array field from CDD Repository with the bounds specified in the data definition However if you use the qualifier OLD_ VERSION CDD_ARRAYS when you extract a data
392. ion ERROR The program contains a WEND that is not immediately followed by a IF User Action Supply a IF immediately following the WEND EXPNOTALL expression not allowed in this context Explanation ERROR The program contains an expression in a context that allows only simple variables array elements or entire arrays for example in FIELD and MOVE statements User Action Remove the expression EXPNOTRES expression does not contribute to result of string concatenation Explanation INFORMATION The compiler has detected an expression that is not needed in determining a result User Action Review the program to determine if the expression can be eliminated You may want to remove the expression if it is determined to be unnecessary EXPTOOCOM expression too complicated Explanation ERROR tThe program contains an expression or statement too complicated to compile This message can occur whenever HP BASIC is unable to allocate sufficient registers User Action Recode as required for example rewrite the statement as two or more less complicated statements Compile Time Error Messages A 29 EXPUNAOPE expecting unary operator or legal lexical operand Explanation ERROR A compiler directive contains an invalid lexical expression for example IF 3 THEN User Action Correct the lexical expression EXTELSFOU extra ELSE directive found Explanation ERROR The program contains a ELSE directive that
393. ion is complete Note that any additional structures that you allocate and link into the RMS structures must be unlinked before exiting the USEROPEN Note Future releases of the OpenVMS Run Time Library might alter the use of some RMS fields Therefore you might have to alter your USEROPEN procedures accordingly The following steps describe the execution of the USEROPEN routine 1 BASIC performs normal OPEN statement processing up to the point where it would call the RMS OPEN CREATE and CONNECT routines BASIC then passes control to the USEROPEN routine 2 BASIC passes the address of the FAB as the first parameter the address of the RAB as the second parameter and the address of the user specified channel number as the third parameter to the routine 3 The USEROPEN routine can modify the contents of the RMS control structures and it must call the RMS OPEN or RMS CREATE routine and the RMS CONNECT routine and return the status in RO Example 13 1 shows how to create a USEROPEN routine to obtain a RAB address File Input and Output 13 41 Example 13 1 Creating a USEROPEN Routine STITLE Example USEROPEN SBTTL Useropen Routine to obtain RAB address SIDENT Version 1 1 FUNCTION LONG Get rab address Fabdef User fab Rabdef User rab LONG Channel FUNCTIONAL DESCRIPTION l Save the address of the RMS Record Access Block allocated by the caller in a global symbol Open the file and return the sta
394. ion of the REPORT directive itself is legal however User Action Recode to eliminate the line continuation or use backslash continuation Compile Time Error Messages A 3 ANSDEFMUS ANSI DEF must be defined before reference Explanation ERROR A program compiled with the ANSI_STANDARD qualifier contains a reference to a DEF function before the function definition User Action Renumber the line containing the function definition so that the definition precedes all references to the function ANSILNREQ a line number is required on first line for ANSI Explanation ERROR When you specify the ANSI qualifier a program must have a line number on the first line for the ANSI qualifier User Action Supply a line number on the first line ANSKEYSPC keywords must be delimited by spaces in ANSI Explanation ERROR A program compiled with the ANSI_STANDARD qualifier contains a line where two elements two keywords a keyword and a line number or a keyword and a string constant are not separated by at least one space For example PRINT Hello User Action Delimit all keywords line numbers and string constants with at least one space ANSLINDIG ANSI line number may not exceed 4 digits Explanation ERROR A program compiled with the ANSI_STANDARD qualifier contains a line number with more than 4 digits that is a number greater than 9999 User Action Renumber the program lines so that no line number exceeds 9999
395. ion structures 9 9 to 9 14 comparison of 9 9 Declarative statements 4 8 7 1 purpose of 7 1 DECLARE statement 6 3 DECwindows Motif 22 1 to 22 5 Bindings 22 1 22 2 Exceptions 22 2 to 22 3 DEF 10 18 to 10 24 formal parameter list 10 18 multiline 10 20 DEF multiline cont d recursion in 10 20 10 23 transferring control into 10 23 transferring control out of 10 23 parameters 10 24 single line 10 18 DEF handling errors in 15 19 Default values specifying with TYPE_DEFAULT 2 17 DEFINE 16 12 DELETE statement 13 21 current and next record pointers after 13 21 Dependency recording 21 7 DEPENDENCY_DATA qualifier 2 8 21 7 21 9 DEPOSIT debugger command 3 12 Descriptors array 17 11 decimal scalar string 17 11 dynamic string 17 10 fixed length string 17 10 packed decimal string 17 11 DET function 6 23 Developing BASIC programs 2 1 to 2 31 Device specific I O performing to a tape drive 18 7 18 18 performing to unit record devices 18 7 to disks 18 10 DIAGNOSTICS qualifier 2 8 Dictionary updating 21 7 DIF function precision of 10 11 DIMENSION statement 6 4 to 6 6 declarative 6 5 executable 6 5 Directives DEFINE 16 12 IF THEN ELSE END IF 16 10 INCLUDE 16 7 21 8 INCLUDE FROM CDD 16 12 REPORT 21 10 Directives cont d UNDEFINE 16 12 VARIANT 16 11 Directories ABORT 16 10 CROSS 16 2 16 6 IDENT 16 2 16 4 IF THEN ELSE
396. irectly following a file specification affects only that file e If the file specifications are separated by plus signs then any positional qualifier directly following a list of file specifications affects only the resulting appended file e The rightmost qualifier overrides any conflicting qualifier previously specified in the command line The placement of these positional qualifiers causes BASIC to produce or not produce listing files object files and diagnostics files For example BASIC LIST OBJ PROG1 NOOBJ DIAG PROG2 PROG3 NOLIST This command does the following e Compiles PROG1 and produces a listing file called PROG1 LIS e Produces no object file for PROG1 e Produces a diagnostics file for PROG1 called PROG1 DIA e Appends PROG2 and PROGS for compilation producing a temporary source file called PROG2 e Compiles the new PROG2 and produces an object file called PROG2 OBJ e Produces no listing file for the new PROG2 HP BASIC does not require line numbers in either of the source files The operator is treated as an OpenVMS append operator HP BASIC appends and compiles the separate files as if they were a single source file 2 2 Developing HP BASIC Programs 2 1 2 BASIC Command Qualifiers The following list shows the BASIC command qualifiers and their defaults A description of each qualifier follows the list The qualifiers that are declining features and no longer recommended are separately described in
397. is not matched with a IF directive User Action Make sure that each ELSE is preceded by a IF and that each IF contains no more than one ELSE clause EXTENDIF extra END IF directive found Explanation ERROR A program unit contains a WEND IF without a preceding IF directive User Action Supply a IF for the WEND IF EXTLEFPAR extra left parenthesis in expression Explanation ERROR A compiler directive contains a lexical expression with an extra left parenthesis User Action Remove the extra parenthesis EXTNAMTOO EXTERNAL name too long truncating to lt new name gt Explanation WARNING An EXTERNAL statement names a symbol longer than 31 characters User Action Shorten the symbol name to 31 characters or less EXTRIGPAR extra right parenthesis in expression Explanation ERROR A compiler directive contains a lexical expression with an extra right parenthesis User Action Remove the extra parenthesis EXTSTRVAR EXTERNAL STRING variables not supported Explanation ERROR The program contains an EXTERNAL statement that specifies an external string variable User Action Remove or change the EXTERNAL statement HP BASIC does not support external string variables A 30 Compile Time Error Messages FEANOTANS language feature not ANSI Explanation INFORMATION A program compiled with the ANSI_ STANDARD qualifier contains a HP BASIC feature such as a long variable name or a string array
398. is information The identification text appears in the first 31 character positions of the second line on each subsequent listing page In the following example the 7IDENT information appears as the first entry on the second line of the listing The information is also included in the object module if the compilation produces one If the linker generates a map listing this information also appears there SIDENT V5 3 SUB PAY If your source module contains multiple IDENT directives BASIC signals a warning and uses the version specified in the first 7IDENT directive 16 2 3 PAGE Directive The PAGE directive causes BASIC to begin a new page in the listing file In the following example the PAGE directives cause BASIC to skip to a new page in the listing file just before each new subtitle Note that to have title and subtitle information appear in the heading of each page you cannot place a line number between the PAGE TITLE and SBTTL directives 16 4 Compiler Directives TITLE Payroll Program SSBTTL Constant Declarations PAGE SBTTL Subroutines PAGE SBTTL Error Handler 16 2 4 LIST and NOLIST Directives LIST and NOLIST are complementary directives The LIST directive causes BASIC to resume adding information to the listing file while the NOLIST directive causes BASIC to stop adding information to the listing file Therefore you can control which parts of the source program are to be listed
399. it is 255 Explanation ERROR An OPEN statement specifies more than 255 index keys User Action Reduce the number of index keys The maximum is 255 TOOMANPAR too many function parameters active Explanation ERROR An external function invocation contains too many expressions in the actual parameter list User Action Reduce the number of expressions in the actual parameter by assigning the expressions to temporary variables TRAFUNONL Transformation functions only permitted with multiplication Explanation ERROR A graphics transformation function is used in a MAT statement other than matrix multiplication User Action Remove the transformation function from the MAT statement TRAOUTRAN transformation number must be in the range 1 255 Explanation ERROR You specified a transformation number that is less than 1 or greater than 255 User Action Change the transformation number to be within the range 1 to 255 TYPDEFSTR TYPE default of STRING is not allowed Explanation ERROR STRING was specified as the default data type in 1 a compiler command 2 a qualifier to the DCL BASIC command or 3 an OPTION statement User Action Specify a numeric data type as the default UNCALLED Routine lt routine gt can never be called Explanation INFORMATION The compiler has detected a routine that is never called User Action Review the program to determine if the routine is needed If it is not you may wa
400. ithmetic 10 10 precision of 10 10 FUNCTION subprograms 12 1 running in the environment 12 4 specifying a data type for 12 9 G GETRFA function 13 28 GET statement 13 16 to 13 18 18 5 current and next record pointers after 13 17 Index 7 GET statement cont d reading data 18 12 reading records with 18 9 sequential 13 16 with REGARDLESS clause 13 18 13 25 with WAIT clause 13 18 13 25 GO debugger command 3 5 GROUP clause 8 5 to 8 9 H Handler attached 15 4 detached 15 5 exiting from 15 6 Handler priorities 15 10 15 18 15 23 HFLOAT data type 21 25 History entry CDD 21 11 H_floating data type 21 25 TO device specific 18 7 network 18 15 performing to ANSI formatted magnetic tapes 18 1 to mailboxes 18 13 T O buffer 13 6 IDENT directive 16 4 IF THEN ELSE END IF 16 10 IF THEN ELSE END IF directive 16 9 IF THEN ELSE statement 9 10 to 9 11 IF modifier 9 1 INCLUDE FROM CDD directive 21 4 INCLUDE directive 7 12 16 7 21 7 21 8 accessing record definitions 16 7 accessing text libraries 16 7 benefits of 16 8 from a file 16 7 Indexed files 13 4 alternate index keys 13 4 index key values 13 4 Index 8 Informational errors 15 1 Initialization of variables 4 12 INKEY function 10 17 Input 5 1 to 5 8 from source program 5 5 to 5 8 from terminal 5 4 from terminal format files 5 4 5 13 to 5 15 interactive 5 1
401. ition contains a field name that is a reserved word in HP BASIC User Action Change the name in the CDD Repository definition or supply an HP BASIC name clause CDDOCCIGN OCCURS DEPENDING ON clause for lt array name gt from CDD Repository ignored Explanation INFORMATION CDD Repository contains an array field with a variable number of elements HP BASIC creates an array large enough for the maximum value User Action If you modify the array field be sure also to change the field that contains the number of array elements CDDOFFERR CDD Repository offset error field lt field name gt offsets out of order Explanation ERROR The CDD Repository definition has been corrupted or there is an internal error in either HP BASIC or CDD Repository User Action If the problem is not in the CDD Repository definition please submit a software problem report SPR with the source code of a small program that produces this error CDDPLUSERR CDD Repository access error Explanation ERROR CDD Repository detected an error while attempting to record dependency data HP BASIC displays the CDD Repository error User Action Take action based on the associated CDD Repository error CDDPREERR decimal precision of lt VALUE gt in CDD Repository out of range for lt field name gt Explanation ERROR The number of fractional digits for a packed decimal field is greater than the total number of digits specified for that field Use
402. itly declare the function with the DECLARE statement the restrictions for naming a multiline DEF function are the same as those for the single line DEF function however explicitly declaring a DEF function can make a program easier to read and understand For instance Example 1 concatenates two strings and Example 2 returns a number in a specified modulus DECLARE STRING FUNCTION concat STRING STRING Declare the function DEF STRING concat STRING Y STRING 2 concat Y Z Define the function FNEND new_string concat A B Invoke the function END DECLARE REAL FUNCTION mdlo REAL INTEGER DEF mdlo REAL argument INTEGER modulus Check for argument equal to zero EXIT DEF IF argument 0 Functions 10 21 Check for modulus equal to zero modulus equal to absolute value of argument and modulus greater than absolute value of argument SELECT modulus CASE 0 EXIT DEF CASE gt ABS argument EXIT DEF CASE ABS argument mdlo argument EXIT DEF END SELECT If argument is negative set flag negative and set argument Ito its absolute value IF argument lt 0 THEN argument ABS argument negatives 1 END IF UNTIL argument lt modulus argument argument modulus If this calculation ever results in zero mdlo returns zero IF argument modulus THEN mdlo 0 EXIT DEF END IF NEXT Argument now contains the right number but the sign might be wrong If the negative argument flag
403. itory inconsistent with allocated size for lt field name gt Explanation FATAL The amount of storage allocated for a field in an HP BASIC RECORD differs from the amount specified by CDD Repository for that record User Action Please submit a software problem report SPR with the source code of a small program that produces this error CDDALCSPN please submit an SPR CDD Repository inconsistent with allocated span for lt field name gt Explanation FATAL The amount of storage allocated by an HP BASIC RECORD for an array differs from the amount specified by CDD Repository for that record User Action Please submit a software problem report SPR with the source code of a small program this error A 10 Compile Time Error Messages CDDAMBFLD ambiguous field name lt name gt for lt RECORD name gt Explanation ERROR More than one CDDL structure share the same level and the same name User Action Change the CDD Repository definition so that the structures have different names CDDATTBAS CDD Repository attributes for lt name gt are other than base 10 Explanation ERROR A field in a CDD Repository definition uses the BASE keyword This warns you that the numeric field is not interpreted as a base 10 number User Action Remove the BASE attribute in CDD Repository or avoid using the field CDDATTDAT CDD Repository data type attribute not permitted for GROUP Explanation ERROR A CDD Repository definition
404. ively If you try to print a negative number in a dollar sign field that does not include either a trailing minus sign or the CR and DR formatting character BASIC signals PRINT USING Format error ERR 116 Negative Fields To allow for a field containing negative values you must place a trailing minus sign in the format field A negative format field causes the value to be printed with a trailing minus sign You can also denote negative fields with CR and DR See Section 14 3 3 8 for more information You must use a trailing minus or the CR DR formatting character to indicate a negative number in an asterisk fill or floating dollar sign field For fields with trailing minus signs BASIC prints a minus sign after negative numbers as shown in Example 1 and a space after positive numbers as shown in Example 2 Formatting Output with the PRINT USING Statement 14 9 14 3 3 5 Example 1 Standard field PRINT USING 10 54 PRINT USING 10 54 END Output 1 10 54 10 54 Example 2 Fields with Trailing Minus Signs PRINT USING 10 54 PRINT USING 10 54 END Output 2 10 54 10 54 E Exponential Format To print a number in E format you must place four carets at the end of the field The carets reserve space for e The capital letter E e A plus or minus sign which indicates a positive or negative exponent e An exponent the exponent is 2 digits for single double and
405. ivision by zero occurs the handler associated with the innermost protected region inner_handler does not clear the error therefore the error is passed to the handler associated with the next outer protected region Outer_handler does not clear this error either and so the error is passed to the default error handler This error is fatal and the program ends abnormally Output is specific to VAX BASIC PROGRAM nesting OPTION TYPE EXPLICIT DECLARE LONG divisor DECLARE REAL dividend quotient WHEN ERROR USE outer handler INPUT Enter divisor Divisor INPUT Enter dividend Dividend WHEN ERROR USE inner handler Quotient Dividend Divisor PRINT The quotient is s Quotient END WHEN END WHEN HANDLER outer_handler Trap data format error IF ERR 50 THEN PRINT Illegal input try again RETRY ELSE PRINT In outer handler PRINT Reverting to default handling now EXIT HANDLER END IF END HANDLER 15 10 Handling Run Time Errors 15 2 4 HANDLER inner handler Trap overflow decimal error IF ERR 181 THEN CONTINUE ELSE PRINT Inside inner handler PRINT Reverting to outer handler now EXIT HANDLER END IF END HANDLER END PROGRAM For more information about exiting program units while an error is pending see Section 15 2 6 Selecting the Severity of Errors to Handle The OPTION HANDLE statement lets you specify the severity level of errors that are to be handled by an error handler in addition to the BASIC e
406. ix that is it sets the value of all elements in real or integer arrays to zero except for those elements on the diagonal from element 1 1 to element n n where n is the largest subscript in the array The elements on the diagonal are set to 1 IDN applies to square arrays only NUL Sets the value of all elements in a string array to the null string except those in row and column zero The array name can specify an existing array MAT statements do not assign values to row and column zero Note that the MAT statement does not require subscripts In the case of existing arrays e If you do not specify subscripts BASIC does not change the current subscripts e If you specify subscripts BASIC redimensions the array to the specified subscripts When redimensioning arrays with MAT you cannot increase the total number of array elements including those in row and column zero 6 12 Arrays When you are creating arrays with MAT e If you do not supply subscripts BASIC assigns two subscripts each with a value of 10 e If you specify subscripts they define the dimensions of the array being implicitly created Subscript values cannot exceed 10 Consider the following example DIM A 10 10 B 15 C 20 20 MAT A ZER Sets all elements of A to 0 MAT B CON 10 Sets elements of B to 1 redimensions B MAT C IDN 10 10 Redimensions C to 10x10 identity matrix PRINT ARRAY A MAT PRINT A PRINT PRINT ARRAY B
407. key value either equals or follows SMITH in the key s collating sequence The second FIND statement finds the first record whose key value follows JONES in the key s collating sequence Each record found by the FIND statement becomes the current record Note that you can only have one current record at a time MAP Emp STRING Emp name LONG Emp number SSN OPEN EMP DAT AS FILE 1 INDEXED amp ACCESS READ amp MAP Emp amp PRIMARY KEY Emp name FIND 1 KEY 0 NXEQ SMITH FIND 1 KEY 0 NX JONES The string expression can contain fewer characters than the key of the record you want to find However if you want to locate a record whose string key field exactly matches the string expression you provide you must pad the string expression with spaces to the exact length of the key of reference For example FIND 5 KEY 0 EQ TOM FIND 5 KEY 0 EQ TOM The first FIND statement locates a record whose primary key field equals TOM The second FIND statement locates the first record whose primary key field begins with TOM Table 13 1 displays the status of the current record and next record pointers after both a sequential and a random access FIND File Input and Output 13 15 13 6 4 Table 13 1 Record Context After a FIND Operation Record Access File Current Mode Type Record Next Record Sequential FIND Sequential Record found Current record 1 Relative Record found Next existing rec
408. l 2 2 1 LINK Command Once you have compiled your source program or module you link it by using the DCL command LINK The LINK command combines your object modules into one executable image which can then be executed by the OpenVMS system A source program or module cannot run on the OpenVMS system until it is linked The format of the LINK command is as follows LINK command qualifier file spec file qualifier 2 22 Developing HP BASIC Programs command qualifier Specifies one or more output file options file spec Specifies the input file or files to be linked file qualifier Specifies one or more input file options If you specify more than one input file you must separate the input file specifications with plus signs or commas By default the linker creates an output file with the name of the first input file specified and the file type EXE When you link more than one file list the file containing the main program first This way the name of your output file will have the same name as that of your main program module The following command line links the object files DANCE OBJ CHACHA OBJ and SWING OBJ to produce one executable image called DANCE EXE LINK DANCE OBJ CHACHA OBJ SWING OBJ 2 2 2 LINK Command Qualifiers The LINK command qualifiers can be used to modify linker output as well as to invoke the debugging and traceback facilities Linker output consists of an image file and a
409. l records equal the length specified by the RECORDSIZE clause when you opened the file 18 4 Advanced File Input and Output 18 1 6 18 1 7 Reading Records from a File The GET statement reads one logical record into the buffer In the following example the first GET reads a group of four records a total of 80 bytes from the file on channel 5 and transfers the first 20 bytes to the record buffers Successive GET operations read 20 byte records to the record buffer performing an I O to the tape every 4 records OPEN MTO TEST DAT FOR INPUT AS FILE 5 amp ORGANIZATION SEQUENTIAL FIXED RECORDSIZE 20 amp BLOCKSIZE 4 ACCESS READ B WHILE BS lt gt NO GET 5 MOVE FROM 5 AS 20 PRINT AS LINPUT Do you want another record B NEXT CLOSE 5 END Controlling Tape Output Format Magnetic tape physical records range from 18 to 8192 bytes With RMS tapes you can optionally specify this size in the BLOCKSIZE clause as a positive integer indicating the number of records in each block HP BASIC then calculates the actual size in bytes Thus a fixed length file on tape with 126 byte records can have a block size from 1 to 64 inclusive The default is 126 bytes one record per block In the following example of an OPEN statement the RECORDSIZE clause defines the size of the records in the file as 90 bytes and BLOCKSIZE defines the size of a block as 12 records 1080 bytes Thus your program contains an I
410. lares it The attributes of the referenced variable do not match those of the declaration User Action Make sure that the variable or array has the same attributes in both the reference and the declaration ATTGTRZER graphics attribute value must be greater than zero Explanation ERROR You specified a negative value when a positive value is required User Action Supply a value greater than zero BADFMTSTR invalid PRINT USING format string Explanation ERROR The PRINT USING format string specified is not valid User Action Supply a valid PRINT USING format string BADLOGIC internal logic error detected Explanation ERROR An internal logic error was detected User Action This error should never occur Please submit a Software Performance Report with a machine readable copy of the source program BADNO qualifier lt name gt does not accept NO Explanation ERROR A qualifier that does not allow a NO prefix was entered For example NODOUBLE User Action Select the proper qualifier BADPROGNM error in program name Explanation ERROR The program name is longer than 39 characters or contains invalid characters User Action Change the program name to be less than or equal to 39 characters and make sure that it contains only letters digits dollar signs and underscores Compile Time Error Messages A 7 BADVALUE lt text gt is an invalid keyword value Explanation FATAL The command supplied
411. lative files randomly by record number that is you can specify the record number of the record to be retrieved For relative files this record number corresponds to the cell number of the desired record You can access indexed files randomly by key The key specification includes a primary or alternate key and its value BASIC retrieves the record corresponding to that value in the particular key chosen You can access disk files of any organization by Record File Address RFA this means that you specify an RFA variable whose value uniquely identifies a particular record The RFA requires six bytes of information For more information about RFAs see Section 13 6 10 File Input and Output 13 5 13 4 I O and Record Buffers An I O buffer is a storage area in your program that RMS uses to store data for I O operations You do not have direct access to I O buffers they are controlled entirely by RMS The I O buffer holds blocks of data transferred from the device and its size is always greater than or equal to that of the record buffer For more information about the amount of storage allocated for T O buffers see the OpenVMS Record Management Services Reference Manual A record buffer is another storage area in your program You have direct access to and control of the record buffer When your program reads a record from a file the information is transferred from the file to the I O buffer in one large chunk of data and then the request
412. lay entire arrays with a single statement They also let you do the following e Implicitly create arrays e Assign names to arrays e Specify array dimensions 6 10 Arrays e Redimension existing arrays to equal or smaller sizes e Assign element values e Print the contents of arrays e Perform matrix arithmetic MAT statements are valid only on arrays of one or two dimensions When MAT statements execute they use row and column zero to store intermediate calculations This means that MAT statements can overwrite data stored in row and column zero of your arrays and you should not depend on data in these elements if your program uses MAT statements Note MAT statements cannot be used with arrays that have lower bounds other than zero An attempt to specify a lower bound other than zero for an array in a MAT statement results in a compile time error The default subscripts for arrays created implicitly with MAT statements are 10 or 10 10 The default is two dimensions This means that if you create an array with a MAT statement and do not specify any subscripts BASIC creates a two dimensional 11 by 11 array If you specify a single subscript BASIC creates a one dimensional array with 11 elements Table 6 1 lists MAT statements and explains their functions Table 6 1 MAT Statements Statement Function MAT Assigns values of zero 1 or a null string to array elements Also copies the values of one array t
413. le and each array element named in the MAP DYNAMIC statement starts at the beginning of the map storage area The MAP DYNAMIC statement is nonexecutable With this statement you cannot specify a string length All string items have a length of zero until the program executes a REMAP statement The REMAP statement specifies the new positions of variables named in the MAP DYNAMIC statement That is it causes HP BASIC to change the internal pointers to the data Because the REMAP statement is executable it can redefine the pointer for a variable or array element each time the REMAP statement is executed With the MAP DYNAMIC statement you can specify either a map name or a previously declared static string variable When you specify a map name a MAP statement with the same map name must lexically precede the MAP DYNAMIC statement Data Definition 7 13 In the following example the MAP statement creates a storage area named emp_buffer The MAP DYNAMIC statement specifies that the positions of variables enp_name and emp_address within the map area can be dynamically defined with the REMAP statement DECLARE LONG CONSTANT emp fixed info 4 9 2 MAP emp buffer LONG badge amp STRING social _sec_num 9 amp BYTE name_length amp address length amp FILL 60 MAP DYNAMIC emp buffer STRING emp name amp emp_address WHILE 1 GET 1 REMAP emp buffer STRING FILL emp fixed_info amp emp name name_length amp em
414. le test The LSET statement in the second line assigns the string XYZ to the variable test but does not change the length of test Because test has a length of 5 the LSET statement pads the string XYZ with two spaces when assigning the value The PRINT statement shows that test includes these two spaces LET test ABCDE LSET test XYZ PRINT test nrn END 11 6 String Handling 11 5 3 Output xyg LSET left justifies a string expression longer than the string variable and truncates it on the right as shown in the following example LET test ABCDE LSET test 12345678 PRINT tests END Output 12345 The LET statement creates the 5 character string variable test The LSET statement in the second line assigns the characters 12345 to test Because LSET does not change the string variable s length it truncates the last three characters 678 RSET Statement The RSET statement right justifies data and assigns it to a string variable without changing the variable s length In the following example C_R is a string variable and cust_rec is a string constant RSET CR cust_rec RSET right justifies a string expression shorter than the string variable and pads it with spaces on the left In the following example the LET statement creates the 5 character string variable test The RSET statement in the second line assigns the string XYZ to test but does not change the length of tes
415. le while the second uses a floating point control variable The first loop executes 100 times and the second 99 times After the ninety ninth iteration of the second loop the internal representation of the value of Floating_point_variable exceeds 10 and BASIC exits the loop Because the first loop uses integer values to control execution HP BASIC does not exit the loop until Integer_variable equals 100 Loop count_1 0 Loop count _2 0 FOR Integer _variable 1 to 100 STEP 1 Loop _count_1 Loop count_1 1 NEXT Integer variable FOR Floating point variable Loop count_2 Loop count_ NEXT Floating point_variable 0 1 to 10 STEP 0 1 2 1 PRINT Integer loop count Loop count 1 PRINT Integer loop end Integer variable PRINT Real loop count Loop count 2 PRINT Real loop end Floating point_variable Output Integer loop count 100 Integer loop end 100 Real loop count 99 Real loop end 9 9 Although it is not recommended programming practice you can assign a value to a FOR NEXT loop s control variable while in the loop This affects the number of times a loop executes For example assigning a value that exceeds the ending value of a loop will cause the loop s execution to end as soon as HP BASIC performs the termination test in the FOR statement Assigning values to ending or step variables however has no effect at all on the loop s execution 9 2 2 WHILE NEXT Loops A WHILE NEXT stat
416. le with the OPTION qualifier Write a main program that accesses the routine in the shareable image Compile the main program and link it with the shareable image The following example shows how to access a shareable image by performing these steps 1 Write and compile a program unit that is to be inserted into a shareable image Program name ADD BAS FUNCTION REAL ADD LONG A LONG B ADD A B FUNCTIONEND Create an options file that will export the function for the link operation Program name ADDSUB OPT SYMBOL ADDER ADD PROCEDURE Link the program with the qualifiers SHAREABLE and OPTION LINK SHAREABLE ADD ADDSUB OPTION Copy the shareable image to SYS SHARE or define a logical name to the full image file specification For example Define ADD Sys Login Add exe Write a main program that accesses the routine in the shareable image Program name CALLADD BAS EXTERNAL REAL FUNCTION ADD LONG LONG DECLARE LONG X Y X 1 Y 2 PRINT ADD X Y END Libraries and Shareable Images 20 5 5 Compile the main program and link it with the shareable image LINK CALLADD ADDMAIN OPTION To link CALLADD with the shareable image ADD you must have a linker options file specifying that ADD is a shareable image For example Options file ADDMAIN OPT ADD SHAREABLE Next execute the program Upon executing the program the image activator attempts to locate the shareable image in the director
417. legal in detached error handlers Explanation ERROR A CONTINUE statement within a detached WHEN block error handler contains a target User Action Remove the target line number or label from the CONTINUE statement or use an attached error handler A 18 Compile Time Error Messages CONIS_INC constant is inconsistent with the type of lt name gt Explanation ERROR A DECLARE CONSTANT statement specifies a value that is inconsistent with the data type of the constant for example a BYTE value specified for a REAL constant User Action Change the declaration so that the data type of the value matches that of the constant CONIS_NEE lt item gt requires conditional expression Explanation ERROR A CASE or IF keyword is immediately followed by a floating point or string expression User Action Supply a conditional expression relational logical or integer CONLFTSID constant lt name gt not allowed on left side of assignment Explanation ERROR The program tries to assign a value to a user defined constant User Action Remove the assignment statement once you have assigned a value to a declared constant you cannot change it CONNOTALL constant lt name gt not allowed in assignment context Explanation ERROR The program tries to assign a value to a user defined constant User Action Remove the assignment statement once you have assigned a value to a declared constant you cannot change it COOMUSB
418. llowing data 1 2 3 4 5 6 7 8 9 10 11 12 13 The MAT INPUT statement reads this data and uses it to fill the array A filling in row 1 before beginning row 2 The MAT INPUT B 2 2 statement dimensions array B to 9 elements 0 to 2 in each dimension and provides values for all the elements except those in row and column zero MAT INPUT 3 A PRINT MAT PRINT A MAT INPUT B 2 2 PRINT MAT PRINT B Output 1 2 3 11 12 13 0 0 0 eS e jam R ae E aa 2 a ao 4 e oOoo0oo0oo0ooo oO ooooococococo amp oooooococooouw oooooococoon oqooooococooco oooojocoeocoo ooooncocoocococo wo oooqocncoooqooor N N w wr e Note that the MAT PRINT statement does not print row and column zero For more information about the MAT PRINT statement see Section 6 6 5 Arrays 6 15 The MAT INPUT statement can also redimension an existing array DIM new array 5 5 MAT INPUT new array 2 4 MAT PRINT new array3 END Output 1 2 3 4 5 6 7 8 1234 567 8 When entering values in response to MAT INPUT you can enter an ampersand amp as the last character on the line and continue on the next line 6 6 4 MAT LINPUT Statement The MAT LINPUT statement assigns string values to string array elements The MAT LINPUT statement reads string values from a terminal format file and writes them to a string array The MAT LINPUT statement prompts for individual array elements It fills the array by rows starting with
419. luate expressions in BASIC programs 3 5 1 Displaying the Values of Variables To display the current value of a variable use the EXAMINE command as follows DBG gt EXAMINE variable name The debugger recognizes the compiler generated data type of the specified variable and retrieves and formats the data accordingly The following examples show some uses of the EXAMINE command Examine a string variable DBG gt EXAMINE EMPLOYEE NAME PAYROLL EMPLOYEE NAME Peter C Lombardi DBG gt Examine three integer variables DBG gt EXAMINE WIDTH LENGTH AREA SIZE WIDTH 4 SIZE LENGTH 7 SIZE AREA 28 DBG gt Examine a two dimensional array of integers two rows and three columns DBG gt EXAMINE INTEGER ARRAY PROG2 INTEGER ARRAY 0 0 27 0 1 31 0 2 12 1 0 15 1 1 22 1 2 18 DBG gt Using the OpenVMS Debugger with BASIC 3 11 Examine element 4 of a one dimensional string array DBG gt EXAMINE CHAR ARRAY 4 PROG2 CHAR_ARRAY 4 m DBG gt Note that the EXAMINE command can be used with any kind of address expression not just a variable name to display the contents of a program location The debugger associates certain default data types with untyped locations You can override the defaults for typed and untyped locations if you want the data to be interpreted and displayed in some other data format The debugger supports the data types and operators of BASIC including RECORDs and RFAs
420. ly LSE is a powerful and flexible text editor designed specifically for software development LSE has important features that help you produce syntactically correct code in HP BASIC SCA is an interactive tool that is used to perform program analysis Optional Programming Productivity Tools C 1 LSE and SCA are closely integrated products generally SCA can be invoked through LSE LSE provides additional editing features that make SCA program analysis more efficient In addition LSE and SCA in conjunction with the HP BASIC compiler provide a set of new enhancements supporting source code designing and review For more information about LSE and SCA see the Guide to Language Sensitive Editor for VMS Systems and Guide to Source Code Analyzer for VMS Systems C 1 1 Preparing an SCA Library SCA stores data generated by the HP BASIC compiler in an SCA library The data in the SCA library contains information about all symbols modules and files encountered during a specific compilation of the source After creating and initializing the OpenVMS directory of the SCA library direct the HP BASIC compiler to generate data analysis files by appending the ANALYSIS_DATA qualifier to the HP BASIC command as follows BASIC ANALYSIS_DATA PG1 PG2 PG3 This command line compiles the input files PG1 BAS PG2 BAS and PG3 BAS and generates corresponding output files for each input file with the file types OBJ and ANA SCA puts these files in your cur
421. m development It is recommended that you use either MAP statements dynamic mapping or MOVE statements to access record contents MAP Statement Normally a record is divided into predetermined fields the sizes of which are known at compile time The MAP statement creates the storage area for this record and determines its total size The following examples show how the MAP statement creates the record storage area Example 1 RECORD name_addr STRING last_name 15 amp street name 30 amp INTEGER house_num END RECORD MAP student_buffer name_addr student_info Example 2 MAP Emp rec STRING Emp name 25 amp LONG Badge amp STRING Address 25 amp STRING Department 4 MAP DYNAMIC and REMAP Statements There are situations where predetermined fields are not applicable or possible In these situations you must perform record defielding in your program at run time Using the MAP DYNAMIC statement you can specify the variables in the map whose positions can change at run time The REMAP statement then specifies the new positions of the variables named in the MAP DYNAMIC statement The following example shows how you can use MAP MAP DYNAMIC and REMAP to deblock your record fields The MAP statement allocates a storage area of 2048 bytes and names it Emp_rec The MAP DYNAMIC statement specifies that the variables Emp_name Badge Address and Department are all located in Emp_rec and that their positions can be
422. m matrix addition or subtraction on input arrays with a different dimensions User Action Use arrays that have identical dimensions ARRMUSSQU Arrays must be square ERR 239 Explanation The program attempts matrix inversion MAT INV on an array that is not inversible User Action Use only square arrays when performing a matrix inversion B 2 Run Time Messages ARRTOOSMA Array too small ERR 197 Explanation The array you referenced with a graphics statement is too small Check the description of the graphics statement to get the minimum size requirement for the array User Action Increase the size of the array BADDIRDEYV Bad directory for device ERR 1 Explanation The device directory does not exist or is unreadable User Action Supply a valid directory BADRECIDE Bad record identifier ERR 143 Explanation The program attempted a record access that specified e A zero or negative record number on a RELATIVE file e A null key value on an INDEXED file User Action Change the record number or key specification to a valid value BADRECVAL Bad RECORDSIZE value on OPEN ERR 148 Explanation The value in the RECORDSIZE clause in the OPEN statement either 1 is zero or greater than 65 535 or 2 does not match the record size of an existing file User Action Change the value in the RECORDSIZE clause CANCHAARR Cannot change array dimensions ERR 240 Explanation The program attempts to redimension an ar
423. mand entered while the debugger Using the OpenVMS Debugger with BASIC 3 13 has stopped at source line 63 causes the debugger to display the source code for deffun and stop execution at source code line 3 DECLARE LONG FUNCTION deffun LONG DECLARE LONG A DEF LONG deffun LONG x deffun x END DEF OF WN Fr gt 63 A deffun 6 64 Print The value of A is A The STEP INTO command is useful for stepping into external functions and DEF functions in HP BASIC If you use this command to step into GOSUB blocks the debugger steps into Run Time Library RTL routines providing you with no useful information In the following program the debugger has suspended execution at source line 8 If you now enter a STEP INTO command the debugger steps into the relevant RTL code and informs you that no source lines are available 1 10 RANDOMIZE gt 8 GOSUB Print_routine 9 STOP 20 Print routine 21 IF Competition Done 22 THEN PRINT The winning ticket is Winning ticket 23 ELSE PRINT The game goes on 24 END IF 25 RETURN As in the previous example a STEP command alone will cause the debugger to proceed directly to source line 9 Table 3 1 summarizes the resultant behavior of the STEP INTO command when used to step into external functions DEF functions and GOSUB blocks 3 14 Using the OpenVMS Debugger with BASIC Table 3 1 Resultant Behavior of the STEP INTO Command Action Results STEP INTO DEF functi
424. ment or access violation error at run time 2 6 Developing HP BASIC Programs e CHECK OVERFLOW enables checking for integers and packed decimal numbers e CHECK NOOVERFLOW disables overflow checking e NOCHECK causes the compiler not to test for arithmetic overflow or for array references outside array boundaries when the program executes e CHECK ALL is the same as CHECK BOUNDS OVERFLOW e CHECK NONE is the same as NOCHECK NO CROSS_REFERENCE NO KEYWORDS NOCROSS_REFERENCE default The CROSS_REFERENCE qualifier causes the compiler to generate a cross reference listing The cross reference list shows program symbols classes and the program lines in which they are referenced Remarks e CROSS_REFERENCE KEYWORDS specifies that the cross reference listing includes all references to BASIC keywords In Alpha BASIC if the LIST qualifier is not specified as well CROSS_REFERENCE is ignored e The default for CROSS_REFERENCE is NOKEYWORDS See Chapter 16 for more information about cross reference listings e NOCROSS_REFERENCE specifies that no cross reference listing be produced NO SYMBOLS NO JTRACEBACK ALL ae NONE NO DEBUG DEBUG TRACEBACK SYMBOLS default The DEBUG qualifier causes the compiler to provide information for the OpenVMS Debugger and the system run time error traceback mechanism Neither TRACEBACK nor SYMBOLS affects a program s executable code F
425. message CLOSEOUT error closing lt file name gt as output Explanation ERROR An error was detected while closing an output file User Action Take corrective action based on the associated message CMDNOTALL command not allowed on programs without line numbers Explanation ERROR A command that cannot be used on a program without line numbers has been used on a program without line numbers User Action Do not use this command on programs without line numbers CODLENEST internal code length estimate error Submit an SPR Explanation FATAL HP BASIC has incorrectly estimated the size of the generated code for your program User Action Submit a software problem report SPR with the program that caused the error You can often work around this error by making a simple change to your code COLOUTRAN color intensities must be in the range 0 0 to 1 0 Explanation ERROR The value specified for color intensity is either less than 0 0 or greater than 1 0 User Action Supply a value from 0 0 to 1 0 COMMAPALIT variable lt name gt not aligned in COMMON MAP lt name gt Explanation INFORMATION In a COMMON or MAP the total storage preceding a REAL WORD LONG or QUAD numeric variable is an odd number of bytes User Action None In HP BASIC numeric data can start on any byte boundary Compile Time Error Messages A 17 COMMAPNEQ COMMON MAP area sizes are not equal for section Explanation WARNING A MAP o
426. methods for receiving 5 1 strings 5 3 to 5 4 Input and output simple 5 1 to 5 15 INPUT LINE statement 5 3 to 5 4 5 13 disabling the prompt 5 4 to 5 5 with strings 11 3 INPUT statement 5 1 to 5 3 5 13 disabling the prompt 5 4 to 5 5 with strings 11 3 Instance RECORD 8 1 Integer variables 4 10 INTEGER data type 4 7 Integer format byte length 17 1 longword 17 2 word length 17 2 INTEGER_SIZE qualifier 2 9 INT function 10 2 INV function 6 22 ITERATE statement 9 14 to 9 16 L Labels 4 3 Language expression EVALUATE debugger command 3 13 with DEPOSIT debugger command 3 12 Language Sensitive Editor See LSE LBOUND function 6 8 Leading zeros with PRINT USING statement 14 11 Left justified format with PRINT USING statement 14 14 LEN function string function 11 9 LET directive 16 8 16 9 LET statement 6 7 6 9 with dynamic strings 11 2 with string data 11 5 Lexical constants creating 16 9 Lexical expressions variations of 16 9 Libraries 20 1 to 20 6 object module 20 1 shareable image 20 1 system supplied 20 1 20 2 user supplied 20 1 20 3 Line number debugger source display 3 3 SET BREAK debugger command 3 8 SET TRACE debugger command 3 10 Line numbers 4 1 programs without 4 1 with INCLUDE directive 16 8 LINE qualifier 3 9 LINES qualifier 2 10 Line terminator accepting as input 5 3 LINK command 2 22 qualifiers of 2 23 Linker error messages 2 2
427. module and the first one encountered by the compiler is smaller than the subsequent ones User Action HP BASIC first allocates MAP and COMMON areas in the main program then MAP and COMMON areas in subprograms in the order in which they were loaded Thus you can avoid this error by loading modules with the largest MAP or COMMON first However it is better practice to make MAP and COMMON areas equal in size AMBRECCOM ambiguous RECORD component Explanation ERROR The program contains an ambiguous RECORD component reference for example A D when both A B D and A C D exist User Action Remove the ambiguity by fully specifying the record component AMPCONILL amp continuation is illegal after INCLUDE directive Explanation ERROR A program contains a INCLUDE directive followed by an ampersand continuation to another statement For example the following is illegal 2300 INCLUDE FROM CDD CDDSTOP PERSONNEL EMPLOYEE amp GOTO 3000 Ampersand continuation of the INCLUDE directive is legal however User Action Recode to eliminate the line continuation or use backslash continuation AMPCONREP amp continuation is illegal after REPORT directive Explanation ERROR A program contains a REPORT directive followed by an ampersand continuation to another statement For example the following is illegal 2300 REPORT DEPENDENCY CDDSTOP PERSONNEL EMPLOYEE COURSE FORM amp GOTO 3000 Ampersand continuat
428. mple EXTERNAL SUB XYZ LONG DIM 1 2 3 A 8 Compile Time Error Messages User Action Remove the array parameter s bound specifications When declaring an external subprogram you can specify only the number of dimensions for an array parameter For example EXTERNAL SUB XYZ LONG DIM BOUMUSTBE bounds must be specified for array Explanation ERROR The program contains an array declaration that does not specify the bounds maximum subscript value For example DECLARE LONG A User Action Supply bounds for the declared array For example DECLARE LONG A 50 50 CANCON can t continue Explanation FATAL A CONTINUE command was typed after changes had been made to the source code User Action After changes have been made to the source code you can run the program but you cannot continue it CAUNOTALL CAUSE statement not allowed in error handler Explanation ERROR A CAUSE statement is specified within an error handler User Action Remove the CAUSE statement from the error handler CDDACCERR CDD Repository access error Explanation ERROR CDD Repository detected an error on an attempted CDD Repository record extraction HP BASIC displays the CDD Repository error User Action Take action based on the associated CDD Repository error CDDACCITE CDD Repository error while accessing item lt field name gt of record Explanation ERROR CDD Repository reported an error when accessing the field Th
429. n doing this you must take care to provide a way out of the loop You can do this with an EXIT statement or by trapping a run time error See Chapter 15 for more information about trapping run time errors 9 2 3 UNTIL NEXT Loops The UNTIL NEXT loop performs like a WHILE NEXT loop except that the logical sense of the conditional expression is reversed that is the UNTIL NEXT loop executes until a given condition is true An UNTIL NEXT loop executes repeatedly for as long as the conditional expression is false Note that in UNTIL NEXT loops the NEXT statement does not increment a control variable You must explicitly change a variable in the conditional expression or the loop will execute indefinitely It is possible to code the WHILE NEXT loop with a UNTIL NEXT loop as shown in the following example These loops are equivalent except for the logical sense of the termination test WHILE Answer lt gt DONE as opposed to UNTIL Answer DONE Program Control 9 7 INPUT Type DONE when finished Answer UNTIL Answer DONE INPUT More data Answer NEXT 9 2 4 Nesting Loops When a loop block is entirely contained in another loop block it is called a nested loop The following example declares a two dimensional array and uses nested FOR NEXT loops to fill the array elements with sales information The inner loop executes 16 times for each iteration of the outer loop This example assigns a
430. n attributes depend on the placement of the qualifier in the command See the OpenVMS User s Manual for more information e NOOBJECT suppresses the creation of an object file During the early stages of program development you might find it helpful to suppress the production of object files until your source program compiles without errors NO OLD_VERSION CDD_ARRAYS NOOLD_VERSION default The OLD_VERSION qualifier causes the compiler to change the lower bound to zero and adjusts the upper bound of the array For example Array 2 5 in CDD Repository is translated by the compiler to be an array with a lower bound of 0 and an upper bound of 3 The compiler issues an informational message to confirm the array bounds Developing HP BASIC Programs 2 11 The NOOLD_VERSION qualifier causes the compiler to extract an array from the CDD Repository with the bounds as specified in the data definition For example Array 2 5 in CDD Repository is translated by the compiler to be an array with a lower bound of 2 and an upper bound of 5 Remarks e OLD_VERSION CDD_ARRAYS is provided for compatibility with previous versions of BASIC e CDD Repository assumes a default lower bound of 1 if none is specified Therefore if no lower bound is specified the compiler translates the CDD Repository array to have a lower bound of 1 For example Array 5 in CDD Repository is translated by HP BASIC to be an array with a lower bound of 1 and
431. n explicit data type ends in a percent or dollar sign User Action Remove the FILL item s percent or dollar sign SUFINTONLY only allowed with BYTE WORD LONG QUAD or INTEGER keywords Explanation ERROR The suffix is only allowed on integer data types User Action Remove the suffix from the variable name or change the data type keyword SUFNOTALL suffix not allowed on variable lt name gt Explanation ERROR A name which cannot end in a percent sign or dollar sign such as a label name ends with either a percent sign or dollar sign User Action Remove the variable s percent or dollar sign Compile Time Error Messages A 83 SUFNOTHAN suffix not allowed on HANDLER lt name gt Explanation ERROR A HANDLER name ends in a percent or dollar sign User Action Remove the percent or dollar sign from the HANDLER name SUFNOTREC suffix not allowed for record type Explanation ERROR A record definition specifies a user defined record type that ends in a percent or dollar sign User Action Remove the record type s percent or dollar sign SUFSTRONLY is only allowed with STRING keyword Explanation ERROR The suffix is only allowed on string data types User Action Remove the suffix from the variable name or change the data type keyword SYNNOTANS syntax check mode not allowed when ANSI Explanation ERROR A SET SYNTAX_ CHECK command was entered when the ANSI_STANDARD qualifier was in
432. n optional map file Image file qualifiers map file qualifiers and debugging and traceback qualifiers are described in this section This section summarizes some of the most commonly used LINK command qualifiers For a complete list and description of LINK qualifiers see the HP OpenVMS Linker Utility Manual BRIEF The BRIEF qualifier causes the linker to produce a summary of the image s characteristics and a list of contributing modules This qualifier is used with MAP NO CROSS_REFERENCE NOCROSS_REFERENCE default The CROSS_REFERENCE qualifier causes the linker to produce cross reference information for global symbols the NOCROSS_REFERENCE qualifier causes the linker to suppress cross reference information Developing HP BASIC Programs 2 23 NO DEBUG NODEBUG default The DEBUG qualifier causes the linker to include the OpenVMS Debugger information in the executable image and generates a symbol table the NODEBUG qualifier causes the linker to prevent debugger control of the program The default is NODEBUG NO JEXECUTABLE file spec EXECUTABLE default The EXECUTABLE qualifier causes the linker to produce an executable image the NOEXECUTABLE qualifier suppresses production of an image file If a file spec is given the resulting image is given the name of the file spec FULL The FULL qualifier causes the linker to produce a summary of the image s characteristics a list of contributing m
433. n terms of the following information e OpenVMS usage e Data type e Type of access allowed e Passing mechanism OpenVMS usages are data structures that are layered on the standard OpenVMS data types For example the OpenVMS usage mask_longword signifies an unsigned longword integer that is used as a bit mask and the OpenVMS usage floating_point represents any OpenVMS floating point data type Table 19 4 lists all the OpenVMS usages and the HP BASIC statements you need to implement them 19 12 Using BASIC in the Common Language Environment Table 19 4 OpenVMS Usages OpenVMS Usage BASIC Implementation access_bit_names access_mode address address_range arg_list ast_procedure boolean byte_signed byte_unsigned channel char_string complex_number cond_value context date_time device_name ef_cluster_name ef_number Not applicable NA BYTE signed LONG LONG address_range or RECORD address_range LONG beginning address LONG ending_address END RECORD NA EXTERNAL LONG FUNCTION ast_proc LONG BYTE BYTE WORD STRING RECORD complex REAL real_part REAL imaginary_part END RECORD LONG LONG QUAD STRING STRING LONG lUse the LOC function to pass the address of an AST routine to a system service Specify BY VALUE for the passing mechanism 2 Although unsigned data structures are not directly supported in BASIC you can substitute the signed equivalent provided you do not ex
434. name of the RECORD statement in your HP BASIC programs After compilation the translated RECORD statement is included as a part of your program s listing The following is an example of a CDD Repository data definition and the translated HP BASIC RECORD statement The examples in this chapter are CDD Repository data definitions in DMU format that were written in the Common Data Definition Language CDDL In all examples a CDDL 21 4 Using CDD Repository with BASIC data definition is displayed in lowercase letters and the translated RECORD statement is displayed in uppercase letters CDDL Definition define record CDDStop basic basicdef description is This is an example record containing only data types supported by HP BASIC employee structure street datatype is text size is 30 characters city datatype is text size is 30 characters state datatype is text size is 2 characters zip code structure new datatype is packed decimal size is 4 digits old datatype is packed decimal size is 5 digits end zip code structure emp number datatype is signed word wage class datatype is text size is 2 characters salary ytd datatype is d floating end employee structure end basicdef Translated RECORD Statement c1 cl cl cl cl cl cl c1 GI cl cl c1 cl cl This is an example record containing only data types supported by HP BASIC RECORD EMPLOYEE UNSPECIFIED STRING STREET 30
435. names variables and arrays All elements of arrays created with the DECLARE statement are initialized to zero or the null string The following statement creates a longword integer array with 11 elements DECLARE LONG FIRST _ARRAY 1980 TO 1990 Note that the STRING data type with the DECLARE statement causes the creation of an array of dynamic strings To create an array of fixed length strings declare the array in a COMMON or MAP statement or as part of a RECORD structure Arrays 6 3 6 2 2 Creating Arrays with the DIM Statement The DIM statement creates and names one or more arrays Use the DIM statement to create an array when you want to e Redimension the array at run time e Create a virtual array When creating arrays with the DIM statement you specify the data type of the array elements with a data type keyword a special suffix on the array name or both The array name can be any valid variable name If you do not supply a data type keyword the data type is determined by the suffix of the array name e Ifthe array name ends with a dollar sign the array stores string data e Ifthe array name ends with a percent sign the array stores integer data e Ifthe array name does not end with either a percent sign or a dollar sign the array stores data of the default type The default type is single precision floating point unless you change the default See Chapter 4 for more information about default data types E
436. nation The program attempted to use PRINT INPUT LINPUT MAT INPUT MAT PRINT or PRINT USING to access a RELATIVE INDEXED or VIRTUAL file User Action Supply a terminal format file TOOFEWARG Too few arguments ERR 97 Explanation A function invocation CALL or DRAW statement passed fewer arguments than were defined in the function picture DEF DEF or subprogram This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Change the number of arguments to match the number defined in the function or subprogram TOOLITDAT too little data in record ERR 189 Explanation An INPUT statement did not find enough data in one line to satisfy all the specified variables This error is signaled only for programs compiled with the ANSI_STANDARD qualifier User Action Supply enough data in the record or reduce the number of specified variables B 28 Run Time Messages TOOMANARG Too many arguments ERR 89 Explanation A function invocation CALL or DRAW statement passed more arguments than were expected This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Reduce the number of arguments A SUB or FUNCTION subprogram can pass a maximum of 255 arguments a DEF function call can pass a maximum of eight arguments TOOMUCDAT too much data in record ERR 177 Explanation The use
437. ncrease the input buffer s size RECHASBEE Record has been deleted ERR 132 Explanation A record previously located by its Record File Address RFA has been deleted User Action None B 24 Run Time Messages RECNOTFOU Record not found ERR 155 Explanation A random access GET or FIND was attempted on a deleted or nonexistent record User Action None RECNUMEXC RECORD number exceeds maximum ERR 147 Explanation The specified record number exceeds the maximum specified for this file User Action Reduce the specified record number The maximum record number cannot be specified in HP BASIC it is either a default or it was specified by a non BASIC program when the file was created RECOVEMAP RECORDSIZE overflows MAP buffer HRR 185 Explanation The OPEN statement specifies a RECORDSIZE value larger than the size of the MAP specified in the MAP clause This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Increase the size of the MAP to match the RECORDSIZE value REDARR Redimensioned array ERR 105 Explanation A MAT statement attempts to redimension an array to have more elements than were originally dimensioned User Action Change the statement that attempts the redimension or increase the original number elements REMOVEBUF REMAP overflows buffer ERR 183 Explanation A REMAP statement causes the variables in the dynamic M
438. nction compare is passed to the subprogram come_back_now using the LOC function EXTERNAL LONG FUNCTION compare LONG LONG EXTERNAL SUB come_back_now LONG BY VALUE CALL come_back_now LOC compare BY VALUE 19 3 Calling HP BASIC Subprograms from Other Languages When you call a HP BASIC subprogram from another language there are some additional considerations that you should be aware of For example although HP BASIC conforms to the OpenVMS Calling Standard you should specify explicit passing mechanisms when calling a routine written in another language The default passing mechanisms of BASIC may not match what the procedure expects In the following section FORTRAN refers to VAX FORTRAN and HP Fortran FORTRAN passes and receives numeric data by reference only the default parameter passing mechanisms are required for passing numeric data back and forth between FORTRAN and HP BASIC programs Both HP BASIC and FORTRAN pass strings by descriptor However FORTRAN subprograms cannot change the length of strings passed to them Therefore if you pass a string to a FORTRAN subprogram you must make sure that the string is long enough to receive the result You do this in one of two ways e Pre extend the string Set the string variable equal to SPACE n where n is large enough to receive the result 19 8 Using BASIC in the Common Language Environment e Define the string as fixed length Name the string in a COMMON or MAP statemen
439. nction declares an array in its parameter list the calling program must pass an array Passing a null parameter instead would cause the program to fail with a memory access violation 19 2 Calling External Routines Most of the steps of calling external routines are the same whether you are calling an external routine written in HP BASIC an external routine written in some other language a system service or a OpenVMS Run Time Library routine The following sections outline the procedure for calling non BASIC external routines For information about calling BASIC routines see Chapter 12 Using BASIC in the Common Language Environment 19 5 19 2 1 19 2 2 Determining the Type of Call Before you call an external routine you must determine whether the call to the routine should be a function call or a procedure call You should call a routine as a function if it returns any type of value If the routine does not return a value you should call it as a procedure Declaring an External Routine and Its Arguments To call an external routine or system routine you need to declare it as an external procedure or function and to declare the names data types and passing mechanisms for the arguments Arguments can be either required or optional You should include the following information in a routine declaration e The name of the external routine e The data types of all the routine parameters e The passing mechanisms for all the routi
440. ndard HP BASIC RECORD or another CDD Repository record User Action Remove one of the duplicate definitions CDDFLDNAM field name missing Explanation ERROR The CDD Repository definition contains a field that is not named User Action Supply a field name for the CDD Repository definition CDDINIIGN initial value specified in CDD Repository ignored for name Explanation INFORMATION tThe specification of an initial value is unsupported by BASIC User Action Set the initial value of this field in your application program CDDINTONLY not allowed on lt name gt with noninteger datatype Explanation ERROR The suffix is allowed only on numeric data types User Action Remove the suffix from the variable name or change the data type keyword CDDLOWBOU lower bound omitted for dimension lt number gt of lt array name gt Explanation ERROR An array in a CDD Repository definition does not specify a lower bound User Action Check to make sure the omission is not a mistake HP BASIC supplies a lower bound of zero and continues after issuing this warning CDDMAXDIM lt array name gt exceeds maximum dimensions Explanation ERROR An array in a CDD Repository definition specifies more than 32 dimensions User Action Reduce the number of dimensions in the CDD Repository definition Compile Time Error Messages A 13 CDDNAMKEY lt name gt is a BASIC keyword Explanation ERROR A CDD Repository defin
441. nded that you not use this type of field for new program development Instead use a single quotation mark to create a 1 character field You must start string format fields with a single quotation mark that reserves a space in the print field followed by e A contiguous series of upper or lowercase Ls for left justified output e A contiguous series of upper or lowercase Rs for right justified output e A contiguous series of upper or lowercase Cs for centered output e A contiguous series of upper or lowercase Es for extended field output BASIC ignores the overflow of strings larger than the string format field except for extended fields For extended fields BASIC extends the field to print the entire string If a string to be printed is shorter than the format field BASIC pads the string field with spaces For more information about extended fields see Section 14 4 4 Formatting Output with the PRINT USING Statement 14 13 14 4 1 14 4 2 A string field containing only a single quotation mark is a 1 character string field BASIC prints the first character of the string expression corresponding to a 1 character string field and ignores all following characters PRINT USING ABCDE END Output A See Section 14 4 4 for an example of different types of fields used together Left Justified Format BASIC prints strings in a left justified field starting with the leftmost character BASIC pads shorter strings with
442. nding to the circuit switch being open or closed 0 The light bulb is off The light bulb is off That s all for now Output 2 Please enter zero or one corresponding to the circuit Switch being open or closed 1 The light bulb is on The light bulb is on Note that a statement in a THEN or ELSE clause can be followed by a modifier In this case the modifying IF applies only to the statement that immediately precedes it IFA B THEN PRINT A IF A 3 ELSE PRINT B IF B gt 0 END IF 9 4 3 SELECT CASE Statement The SELECT CASE statement lets you specify an expression the SELECT expression any number of possible values cases for the SELECT expression and a list of statements a CASE block for each case The SELECT expression can be a numeric or string value CASE values can be single or multiple values one or more ranges of values or relationships When a match is found between the SELECT expression and a CASE value the statements in the following CASE block are executed Control is then transferred to the statement following the END SELECT statement In the following example the CASE values appear to overlap that is the CASE value that tests for values greater than or equal to 0 5 also includes the values greater than or equal to 1 0 However HP BASIC executes the statements associated with the first matching CASE statement and then transfers control to the statement following END SELECT In this pro
443. ne of the nodes in a DECnet for OpenVMS VAX you can communicate with other nodes in the network with HP BASIC program statements HP BASIC lets you do the following e Read and write files on a remote node as you do files on your own system remote file access e Exchange data with a process executing at a remote location task to task communication Remote File Access To write or read files at a remote site include the node name as part of the file specification For example OPEN WESTON DUA1 HOLT TEST DAT 2 FOR INPUT AS FILE 2 You can also assign a logical name to the file specification and use that logical name in all file I O Note You need NETMBxX privileges to access files at a remote node If the account at the remote site requires a username and password include this access string in the file specification You do this by enclosing the access string in quotation marks and placing it between the node name and the double colon The following file specification accesses the account HOLT TMP on node WESTON by giving the username HOLT and the password PASWRD After accessing the file your HP BASIC program can read and write records as if the file were in your account Advanced File Input and Output 18 15 OPEN WESTON HOLT PASWRD DUA0 HOLT TMP INDEXU DAT 4 amp FOR INPUT AS FILE 1 INDEXED PRIMARY TEXTS Do not use the CONNECT clause when opening a file on a remote node or HP BASIC will signal
444. ne parameters provided that the routine is not written in HP BASIC When you declare an external routine use the EXTERNAL statement This allows you to specify the data types and parameter passing mechanisms only once In the following example the EXTERNAL statement declares cobsub as an external subprogram with two parameters a LONG integer and a string both passed by reference EXTERNAL SUB cobsub LONG BY REF STRING BY REF With the EXTERNAL statement HP BASIC allows you to specify that particular parameters do not have to conform to specific data types and that all parameters past a certain point are optional A parameter declared as ANY indicates that any data type can appear in the parameter position In the following example the EXTERNAL statement declares a SUB subprogram named allocate This subprogram has three parameters one LONG integer and two that can be of any HP BASIC data type EXTERNAL SUB allocate LONG ANY A parameter declared as OPTIONAL indicates that all following parameters are optional You can have both required and optional parameters The required parameters however must appear before the OPTIONAL keyword because all parameters following it are considered optional 19 6 Using BASIC in the Common Language Environment EXTERNAL 19 2 3 EXTERNAL In the following example the EXTERNAL statement declares the Run Time Library routine LIB LOOKUP_KEY The keyword OPTIONAL is specified to indica
445. nel number to be greater than zero INVCONREQ invalid conversion requested Explanation ERROR The program contains a reference to the REAL or INTEGER functions and the argument is an entire array GROUP RECORD or RFA expression User Action Remove the invalid argument The argument to these functions must be a numeric expression Compile Time Error Messages A 45 INVINTTYP invalid integer type Explanation ERROR A reference to the INTEGER function contains an invalid data type keyword for example A INTEGER A SINGLE User Action Change the invalid data type keyword The INTEGER function returns only BYTE WORD LONG or QUAD values INVLOGNAM invalid logical name Explanation ERROR The argument to the ASSIGN compiler command specified a logical name length of less than 1 or greater than 63 User Action Supply a valid logical name INVPRISPE invalid priority specification expecting lt or gt Explanation ERROR On the SET INPUT PRIORITY statement you specified a character other than lt or gt to indicate the relative priorities of the two transformation numbers User Action Specify the priority relationship with less than lt lower priority or greater than gt higher priority INVREATYP invalid real type Explanation ERROR A reference to the REAL function contains an invalid data type keyword for example A REAL A LONG User Action Change the invalid data type keyword The REA
446. nguages you typically use routine names labels or line numbers possibly with directory specifications to ensure uniqueness Routine names and labels should be specified as they appear in the source code Line numbers may be derived from either a source code display or a listing file When specifying a line number use the prefix LINE Otherwise the debugger will interpret the line number as a memory location For example Using the OpenVMS Debugger with BASIC 3 7 the next command sets a breakpoint at line 41 of the currently executing module the debugger will suspend execution when the PC is at the start of line 41 DBG gt SET BREAK LINE 41 Note that you can set breakpoints only on lines that resulted in machine code instructions The debugger warns you if you try to do otherwise for example on a comment line If you want to pick a line number in a module other than the one currently executing you need to specify the module s name in a directory specification For example DBG gt SET BREAK SCREEN_I0 LINE 58 You do not always have to specify a particular program location such as line 58 or COUNTER to set a breakpoint You can set breakpoints on events such as exceptions You can use the SET BREAK command with a qualifier but no parameter to break on every line or on every CALL instruction and so on For example DBG gt SET BREAK LINE DBG gt SET BREAK CALL You can conditionalize a breakpoint with a WHEN clau
447. nown as the DMU naming convention For example CDDS TOP PERSONNEL EMPLOYEES REC Relative path name CDD Repository always begins its search at CDD TOP or at the anchor you specify unless you define another directory or object to be the start of your directory You can do this by assigning the name of a dictionary directory to the logical name CDD DEFAULT For example DEFINE CDDSDEFAULT CDDSTOP BASIC Using this command defines the dictionary directory CDD TOP BASIC as the default start of your directory You can override the defined default by specifying CDD TOP in a path name You can omit the origin of a path name and specify a relative path name Any path name that does not begin with either CDD TOP or an anchor is automatically appended to the current CDD DEFAULT For example you can specify PERSONNEL EMPLOYEES REC If CDD DEFAULT is MYNODE MY DISK MYDIR the relative path name is the same as MYNODE MYSDISK MYDIR PERSONNEL EMPLOYEES REC Similarly if CDD DEFAULT is CDD TOP MYDIR the relative path name is the same as CDD TOP MYDIR PERSONNEL EMPLOYEES REC Using CDD Repository with BASIC 21 3 21 2 3 21 2 4 21 2 5 Dictionary Entities Several types of entities can exist in a dictionary For example DMU format and CDO format dictionaries each contain record entities database entities and form entities HP BASIC creates a compiled module entity and relationships in CDD Repository dictionaries
448. nstance RECORD component names need not be unique in your program For example you can have a RECORD component called First_name in any number of different RECORD statements References to this component are unambiguous because every RECORD component reference must specify the record instance in which it resides 8 4 Creating and Using Data Structures 8 1 1 Grouping RECORD Components A RECORD component can consist of a named group of instances identified with the keyword GROUP You use GROUP to refer to a collection of RECORD components or to create an array of components that have different data types The GROUP name can be followed by a list of upper and lower bounds which define an array of the GROUP components GROUP is valid only within a RECORD block The declarations between the GROUP statement and the END GROUP statement are called a GROUP block The following example declares a RECORD template of data type Yacht Yacht is made up of two groups Type_of_yacht and Specifications Each of these groups is composed of elementary RECORD components BASIC also allows groups within other groups RECORD Yacht GROUP Type of yacht STRING Manufacturer 10 STRING Model 10 END GROUP Type of yacht GROUP Specifications STRING Rig 6 STRING Length over all 3 DECIMAL 5 0 Displacement DECIMAL 2 0 Beam DECIMAL 7 2 Price END GROUP Specifications END RECORD Yacht 8 1 2 RECORD Variants Sometimes it is useful to have di
449. nt of a compiler directive Lexical expression Lexical variable Statement line may or may not be numbered Statement line number Literal value in quotation marks Logical expression 1 to 63 character logical name to be associated with equiv name User identifier following the rules for BASIC identifiers Specific to a MAP statement Two dimensional array Name or identifier indicates the declaration of a name or the name of a BASIC structure such as a SUB subprogram Numeric value Numeric literal Parameter list such as for a SUB subprogram Valid BASIC passing mechanism Program name Floating point value Real expression Real variable Record expression record number within a file Relational expression Oracle CDD Repository protocol Identifier keyword compiler directive literal constant or operator SUB subprogram or other callable procedure Character string Expression that represents a character string String literal Variable that contains a character string Specific to a SUB subprogram target Target point of a branch statement either a line number or a label unq str Unique string unsubs var Unsubscripted variable as opposed to an array element var Variable XXV Part Developing BASIC Programs on OpenVMS Systems Part I provides an overview of BASIC and describes how to develop and debug BASIC programs It shows you how to get started on the OpenVMS system and how to develop programs 1
450. nt to remove it A 86 Compile Time Error Messages UNDEFINED unresolved undefined symbols Explanation ERROR A program executed in the VAX BASIC Environment calls or invokes a subprogram or routine that has not been loaded User Action Load the subprogram or routine before running the program in the VAX BASIC Environment UNDLINNUM undefined line number Explanation ERROR A statement tries to transfer control to a nonexistent line Or in a numberless program a line number is referenced User Action Replace the nonexistent line number with the correct destination line number or label UNELEXDIR unexpected lexical directive encountered Explanation ERROR The specified lexical directive is not legal in this statement User Action Use a supported lexical directive UNEXPEOF unexpected end of file Explanation ERROR An end of file was specified immediately after an ampersand continuation character User Action Remove the ampersand continuation character or continue the line UNINIT variable lt variable gt is fetched not initialized Explanation INFORMATION tThe compiler has detected a variable that is used but not initialized User Action Review the program to determine if the variable should be initialized before use If necessary you may want to add code to initialize the variable UNKCOMINP unknown command input Explanation ERROR An attempt was made to enter an invalid or unknown comm
451. ntations and Default Allocation 5 54 4 ba0 bs oe ates Ya hee bo dew eho ane aes 7 10 String Arithmetic Functions 000 eee eee 10 10 Precision of String Arithmetic Functions 10 10 String Modification 0 0 0 ee eee 11 2 EDITS Options i 4c u 24 bees be a bee vase bes 11 17 Record Context After a FIND Operation 13 16 Record Context After a GET Operation 13 17 Record Context After a PUT Operation 13 19 RMS Control Structures Set for the USEROPEN Clause 13 40 Format Characters for Numeric Fields 14 6 Format Characters for String Fields 14 13 Valid Parameter Passing Mechanisms 19 3 Run Time Library Facilities 000000005 19 11 19 3 19 4 21 1 21 2 B 1 B 2 System Servi 656465266 2044644 4000 4600400040884 OpenVMS Usages seres ensin Es EERIE eee teens Supported CDD Repository Data Types Unsupported CDD Repository Data Types BASIC Run Time Errors 0000 0 Errors Not Generated by HP BASIC xvii Preface This manual describes how to develop and use HP BASIC programs on OpenVMS systems and describes BASIC language features Note In this manual the term OpenVMS refers to both OpenVMS 164 and OpenVMS Alpha systems If there are differences in the behavior of the HP BASIC compiler on the two operating sys
452. ntered points not within a transformation ERR 285 Explanation Input points are not within the viewport of a defined transformation User Action Issue a warning to the user to input points within the defined area Alternatively you can change at least one transformation to include the viewport area not defined At the start of program execution transformation 1 includes all of NDC space Optionally you can define one transformation to cover the default viewport ERRFILCOR Error on OPEN file corrupted ERR 178 Explanation The program attempted to open an invalid structure on disk User Action See your system manager ERRTRANEE ERROR trap needs RESUME ERR 246 Explanation An error handler attempts to execute an END END SUB END FUNCTION SUBEND FUNCTIONEND or FNEND statement without first executing a RESUME statement This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Change the program logic so that the error handler executes a RESUME statement before executing an END END SUB END DEF SUBEND FUNCTIONEND or FNEND statement FATSYSIO_ Fatal system I O failure ERR 12 Explanation An I O error has occurred in 1 the system or 2 Record Management Services The last operation will not be completed User Action See the OpenVMS System Messages and Recovery Procedures Reference Manual for RMS errors or retry the operation Use VMSSTATUS to r
453. ntly compiled program is the last program unit in the source file If you use the OLD command to read a program into memory and load one or more object modules then type RUN the currently compiled procedure is the program you read into memory with OLD ILLIDEPDP illegal IDENT string for PDP 11 Explanation INFORMATION A IDENT compiler directive contains a string that is invalid for PDP 11 systems This error is issued only when the BP2 compatibility flagger is enabled User Action Change the IDENT string The string must be from 1 to 6 characters and must contain only RAD 50 characters ILLIO_CHA illegal I O channel Explanation ERROR A constant channel expression is greater than 99 or a variable channel expression is greater than 119 User Action If the channel expression is a constant change to be less than or equal to 99 A variable channel expression can be less than or equal to 119 however channels in the range 100 to 119 are reserved for programs using LIB GET_LUN A 38 Compile Time Error Messages ILLLINNUM illegal line number in CHAIN Explanation ERROR A CHAIN with LINE statement specifies an invalid line number Either the number is outside the valid range or a string expression follows the LINE keyword User Action Supply an integer line number from 1 to 32 767 inclusive ILLLOCARG illegal LOC argument Explanation ERROR An argument to the LOC function is a constant virtual array element
454. nts with 6 16 redimensioning arrays with 6 16 MAT PRINT statement 6 17 with comma 6 17 with semicolon 6 17 MAT READ statement 6 14 subscripts in 6 14 with DATA statement 6 14 Matrix 6 1 arithmetic 6 19 functions 6 21 to 6 23 MAT statement 6 5 6 12 adding elements of arrays 6 20 assigning array values from other arrays 6 19 assigning values with 6 10 creating arrays with 6 13 displaying values with 6 10 for array computations 6 19 to 6 23 keywords 6 12 multiplying elements of arrays 6 20 redimensioning with 6 12 subscripts in 6 12 subtracting elements of arrays 6 20 use of row and column zero 6 11 with implicitly created arrays 6 11 MAT statements 6 10 to 6 18 Messages run time B 1 Index 10 MID assignment statement 11 8 MID function string function 11 14 Mixed mode expressions 7 3 Modifiers statement 9 1 to 9 3 Module names 4 4 12 10 Motif See DECwindows Motif MOVE statement 13 6 13 9 to 13 10 default string lengths 13 9 valid variables in 13 9 Multiplication of matrices 6 20 N Names variables 4 10 Negative format fields with PRINT USING statement 14 9 Network I O 18 15 Next record pointer 13 5 NOCROSS directive 16 6 NOECHO function 10 16 NOLINE with ERL function 15 13 NOLIST directive 16 5 Nonprinting characters 4 5 NOOBJECT qualifier 21 4 NOREWIND positioning tape 18 3 NOTBASIC errors 15 15 to 15
455. number of elements in a dimension you count from zero to the bound specified BASIC Concepts and Elements 4 11 The following DECLARE statement creates an 11 by 11 array of integers Therefore the array contains a total of 121 array elements DECLARE INTEGER My array 10 10 There are many applications where you need to reference data for a particular range of values You can specify a lower bound other than zero for your arrays The following example declares an array containing the birth rates for the years from 1945 to 1985 OPTION TYPE EXPLICIT amp SIZE REAL SINGLE DECLARE REAL Birth_rates 1945 TO 1985 Subscripts define the position of an element in an array the expression Birth_rates 1970 refers to the 26th value of the array Birth_rates For more information about arrays see Chapter 6 Note By default the compiler signals an error if a subscript is larger than the allowable range Also the amount of storage that the system can allocate depends on available memory Therefore very large arrays can cause an internal allocation error 4 7 6 Initialization of Variables BASIC sets variables to zero or null values at the start of program execution Variables initialized include the following e Numeric variables and array elements except those in MAP or COMMON statements e String variables and array elements except those in MAP or COMMON statements e Variables in subprograms Subprogram vari
456. numbered consecutively from 1 to n where n represents the relative record number Each cell can contain only a single record For fixed length records the length of each cell equals the record length plus 1 byte For variable length records the length of the cell equals the maximum record size plus 3 bytes You can access records in a relative file either sequentially or randomly The relative record number is the key value in random access mode that is to access a record in a relative file in random access mode you must know the relative record number of that record You can add records to a relative file either at the end of the file or into any empty cell Relative files are most useful when randomly accessed and when the record can be identified by its cell number for example when inventory numbers correspond to cell numbers Relative files support shared access You can delete records from relative files but not sequential files File Input and Output 13 3 13 2 4 Indexed Files An indexed file contains data records that are sorted in ascending or descending order according to a primary index key value The index key is a record field or set of fields that determines the order in which the records are logically accessed Keys must be variables declared in a MAP statement Keys can be any one of the following e Strings e WORD integers e LONG integers e Quadword integers e Packed decimal numbers String keys can also b
457. o another and performs matrix arithmetic MAT READ Assigns DATA statement values to array elements MAT INPUT Assigns values to array elements from your terminal or a terminal format file MAT LINPUT Assigns string values to string array elements from your terminal or from a terminal format file MAT PRINT Displays the contents of an array on your terminal or writes array element values to a terminal format file In the following example the first MAT statement creates the string array z_array with eight rows and eight columns and assigns a null string to all Arrays 6 11 elements The second MAT statement redimensions the array to six rows and six columns The third MAT statement adds the values in each corresponding element of arrays B and C and stores the values in the corresponding elements of array A MAT z_array NULS 7 7 MAT z_array NULS 5 5 MATA B C END 6 6 1 MAT Statement The MAT statement can create an array and optionally assign values to all elements in that array By specifying one of the MAT statement keywords you can initialize arrays in one of four ways Table 6 2 lists the MAT statement keywords and their functions Table 6 2 MAT Statement Keywords MAT Keyword Function ZER Sets the value of all elements in a numeric array to zero CON Sets the value of all elements in a numeric array to 1 except those in row and column zero IDN Sets the array to the identity matr
458. o the protected region while in Example 2 the handler catch_handler is detached and must be provided elsewhere in the program unit Example 1 WHEN ERROR IN protected_statement_1 protected_statement_ 2 USE handler statement_1 handler statement _2 END WHEN 15 2 Handling Run Time Errors 15 2 1 Example 2 WHEN ERROR USE catch_handler protected statement _1 protected statement 2 END WHEN HANDLER catch_handler handler statement_1 handler statement 2 END HANDLER The following sections further explain the concepts of protected regions and handlers Protected Regions A protected region is a block of code that is monitored by the compiler for the occurrence of an error The bounds of this region are determined by the actual ordering of the source code Statements that are lexically between a WHEN ERROR statement and a USE or END WHEN statement are in the protected region If an error occurs inside the protected region control passes to the error handler associated with the WHEN ERROR statement When an error occurs beyond the limits of a protected region default error handling is in effect unless other error handlers are provided For more details about handler priorities see Section 15 2 3 and Section 15 3 The WHEN ERROR statement signals the start of a block of protected statements The WHEN ERROR statement also specifies the handler to be used for any errors that occur inside the protected region The keyword U
459. ocess terminates No entry for this file is made in any directory 13 8 11 USEROPEN Clause The USEROPEN clause specifies an external long function that BASIC executes when you open or create a file You do not need to declare the USEROPEN routine with an EXTERNAL FUNCTION statement This procedure can then specify additional OPEN parameters for the file For example OPEN FILE DAT FOR INPUT AS FILE 23 amp ORGANIZATION INDEXED USEROPEN Myopen MAP ABC The code in Myopen determines how the file FILE DAT is opened The Run Time Library sets up six RMS control structures before calling the USEROPEN procedure Table 13 4 defines these structures and their meanings Table 13 4 RMS Control Structures Set for the USEROPEN Clause Structure Definition FAB File Access Block RAB Record Access Block NAM Name Block XAB FHC Extended Attributes Block ESA Expanded Name String RSA Resultant Name String A USEROPEN procedure should not alter the allocation of these structures although it can modify the contents of many of the fields You should not modify fields set by other OPEN statement keywords For example you should use the RECORDSIZE clause not a USEROPEN routine to set the record length 13 40 File Input and Output The allocation of the RMS control structures except for the RAB lasts only for the duration of the OPEN statement Therefore your USEROPEN can retain only the RAB address for use after the OPEN operat
460. odule entities and file entities to the dictionary nor does it create dependency relationships in the dictionary unless you specify the DEPENDENCY_DATA qualifier Using CDD Repository with BASIC 21 7 21 3 2 Creating Relationships with Included Record Definitions In Section 21 2 4 a record description is defined as a set of fields thus establishing a simple relationship in CDD Repository between the record and its fields With that record description defined you can include it in a HP BASIC program With either a DMU format or CDO format dictionary the compiler can extract a record description into a program Use the INCLUDE lexical directive in the source program The format is as follows SINCLUDE FROM CDD pathname For example the following BASIC source code extracts a record description named ADDRESS_REC from CDD Repository PROGRAM EXAMPLE1 SINCLUDE FROM CDD CDD TOP SMITH ADDRESS REC DECLARE ADDRESS REC TEST RECORD INPUT INPUT INPUT INPUT INPUT INPUT PRINT PRINT PRINT First name TEST RECORD FIRST NAME Last name TEST RECORD LAST NAME Address TEST RECORD ADDRESS City TEST RECORD CITY State TEST RECORD STATE Zip code TEST RECORD ZIP_CODE TEST RECORD FIRST NAME TEST RECORD LAST NAME TEST RECORD ADDRESS TEST RECORD CITY TEST RECORD STATE TEST RECORD ZIP_CODE The following shows the content of the record cl cl c1 cl cl cl CSCO WADI amp Ww
461. odules listings of global symbols by name and by value and a summary of characteristics of image sections in the linked image This qualifier is used with MAP NO MAP file spec NOMAP default interactive mode MAP default batch mode The MAP qualifier causes the linker to generate a map file the NOMAP qualifier suppresses the map If a file spec is given the map file is given the name of the file spec NO SHAREABLE NOSHAREABLE default The SHAREABLE qualifier causes the linker to create a shareable image the NOSHAREABLE qualifier generates an executable image NOJTRACEBACK TRACEBACK default The TRACEBACK qualifier causes the linker to generate symbolic traceback information when error messages are produced the NOTRACEBACK qualifier suppresses traceback information 2 24 Developing HP BASIC Programs 2 2 3 Linker Input Files You can specify the object modules to be included in an executable image in any of the following ways e Specify input file specifications for the object modules If no file type is specified the linker assumes that an input file is an object file with the file type OBJ e Specify one or more object module library files You can either specify the name of an object module library with the LIBRARY qualifier or specify the names of object modules contained in an object module library with the INCLUDE qualifier The uses of object module libraries are described in Section 2
462. of a particular OpenVMS Run Time Library facility Table 19 2 lists all the language independent Run Time Library facility prefixes and the types of tasks each facility performs Table 19 2 Run Time Library Facilities Facility Prefix Types of Tasks Performed DTK DECtalk routines that are used to control the DECtalk device LIB General purpose routines that obtain records from devices manipulate strings convert data types for I O allocate resources obtain system information signal exceptions establish condition handlers enable detection of hardware exceptions and process cross reference data MTH Mathematics routines that perform arithmetic algebraic and trigonometric calculations OTS Language independent support routines that perform tasks such as data type conversions as part of a compiler s generated code PPL Parallel processing routines that help you implement concurrent programs on single CPU and multiprocessor systems SMG Screen management routines that are used in designing composing and keeping track of complex images on a video screen STR String manipulation routines that perform such tasks as searching for substrings concatenating strings and prefixing and appending strings System Service Routines System services are system routines that perform a variety of tasks such as controlling processes communicating among processes and coordinating I O Unlike the OpenVMS Run Time Library routines whi
463. of the line in which the text appears In specifies text that was either accessed from a source file or from a text library and Cn specifies a record definition that was accessed from CDD Repository Both the I and the C tell you that the text was accessed with the INCLUDE directive and n tells you the nesting level of the included text The INCLUDE directive is useful when you want to share code among multiple program modules To do this you must first create a file that contains the shareable code then include that file in all the modules that require it Thus you reduce the chance of a typographical error You can prevent the INCLUDE file code from appearing in the compilation listing by using the BASIC command qualifier SHOW NOINCLUDE or SHOW NOCDD_DEFINITIONS For text files and text library modules use the qualifier SHOW NOINCLUDE For CDD Repository definitions use the qualifier SHOW NOCDD_DEFINITIONS 16 4 Controlling Compilation BASIC lets you control the compilation of a program by creating and testing lexical constants You create and assign values to lexical constants with the LET directive These constants are always LONG integers You control the compilation by using the IF THEN ELSE END IF directive to test these lexical constants Thus you can conditionally e Supply different values for program variables and constants e Skip over part of a program e Abort a compilation e Include BASIC so
464. of_handler IF ERR EOF THEN PRINT End of file ELSE EXIT HANDLER END IF END HANDLER END 7 7 2 2 Multiple Maps When a program contains more than one map with the same name the storage allocated by these MAP statements is overlaid This technique is useful for manipulating strings Figure 7 1 shows multiple maps and maps in use 7 8 Data Definition Figure 7 1 Multiple Maps NAME 40 BYTES ADDRESS 44 BYTES P _ S AS AA AN FIRST NAMES LAST NAMES STREET STREETS CITY NUMBER 15 BYTES 25 BYTES 16 BYTES 23 BYTES 5 BYTES ZK 5183 GE When you use more than one map to access a record buffer HP BASIC uses the size of the largest map to determine the size of the record The RECORDSIZE clause of the OPEN statement can override this map defined record size For more information see Chapter 183 You can also use multiple maps to interpret numeric data in more than one way The following example creates a map area named barray The first MAP statement allocates 26 bytes of storage in the form of an integer BYTE array The second MAP statement defines this same storage as a 26 byte string named ABC When the FOR NEXT loop executes it assigns values corresponding to the ASCII values for the uppercase letters A to Z MAP barray BYTE alphabet 25 MAP barray STRING ABC 26 FOR I 0 TO 25 alphabet I I 65 NEXT I PRINT ABC END Output ABCDEFGHIJKLMNOPORSTUVW
465. oint value of a numeric string The numeric string expression must be the string representation of some number It can contain the ASCII characters 0 to 9 a plus sign a minus sign or an uppercase E The VAL function returns a number of the default floating point data type HP BASIC signals Illegal number ERR 52 if the argument is outside the range of the default floating point data type The following is an example of VAL and VAL A VAL 922 BS 100 C VALS BS PRINT A PRINT C END Output 922 100 Functions 10 9 10 1 4 String Arithmetic Functions In BASIC string arithmetic functions process numeric strings as arithmetic operands This lets you add SUM subtract DIF multiply PROD and divide QUO numeric strings and express them at a specified level of precision PLACE String arithmetic offers greater precision than floating point arithmetic or longword integers and eliminates the need for scaling However string arithmetic executes more slowly than the corresponding integer or floating point operations The operands for the functions can be numeric strings representing any integer or floating point value E notation is not valid Table 10 1 shows the string arithmetic functions and their formats and gives brief descriptions of what they do Table 10 1 String Arithmetic Functions Function Format Description SUM SUM A B B is added to A DIF DIF A B
466. ol to the first target in the list if the value is 2 control passes to the second target and so on If the value is less than 1 or greater than the number of targets in the list HP BASIC transfers control to the target specified in the OTHERWISE clause For example Menu PRINT Would you like to change PRINT 1 First name PRINT 2 Last name INPUT CHOICE ON CHOICES GOTO First_name Last_name OTHERWISE Other choice First_name INPUT First name firstname GOTO Done Last_name INPUT Last name lastnames GOTO Done Other choice PRINT Invalid choice PRINT Let s try again GOTO Menu Done END Note that if you do not supply an OTHERWISE clause and the control variable is less than 1 or greater than the number of targets BASIC signals ON statement out of range ERR 58 Program Control 9 9 9 4 2 IF THEN ELSE Statement The IF THEN ELSE statement evaluates a conditional expression and uses the result to determine which block of statements to execute next If the conditional expression is true HP BASIC executes the statements in the THEN clause If the conditional expression is false HP BASIC executes the statements in the ELSE clause if one is present If the conditional expression is false and there is no ELSE clause HP BASIC executes the statement immediately following the END IF statement In the following example HP BASIC evaluates the conditional expression number lt 0 If the inp
467. ollowing example contains both comments and program statements Any text that follows an exclamation point is ignored BASIC Concepts and Elements 4 5 PROGRAM sample i y Require that all variables be declared Fa OPTION TYPE EXPLICIT i Set up error handler la WHEN ERROR USE Error_routine d Declarations hs END PROGRAM You can also mix comments and code on the same line For example DECLARE amp INTEGER amp Print page Current page number amp Print line Current line number amp Print_column Current column number All text between the exclamation point and the carriage return is ignored with one exception the ampersand is still recognized This is a continuation character that specifies that a single statement is being continued on the next line Only spaces and tabs are valid between the ampersand and the carriage return Note Although you can also terminate a comment field with an exclamation point this practice is not recommended Any text that follows the second exclamation point is treated as part of your program code 4 5 Declarations and Data Types Following are methods for creating variables and specifying data types e Implicit data typing e Explicit data typing 4 6 BASIC Concepts and Elements With implicit data typing BASIC creates and specifies a data type for a variable the first time you reference it in your program With explicit data typing you must use one of fou
468. ollows BAS lt gt lt mnemonic gt lt message gt BAS I FROLINMOD from Line x in module y lt l gt Is a letter indicating the severity of the error The severity indicator can be one of the following e J Indicating information e W lIndicating a warning Run Time Messages B 1 e EK Indicating an error e F Indicating a severe error lt mnemonic gt Is a 3 to 9 character string that identifies the error lt X gt Is the line number where the error occurred lt Y gt Is the name of the module where the error occurred Warning error messages indicate that an error has occurred but program execution continues In some cases HP BASIC reprompts for more information or correct data in other cases HP BASIC performs the specified operation but the results are not as expected Fatal error messages indicate that the program has aborted ARGDONMAT Arguments don t match ERR 88 Explanation The proper array descriptor was not specified for a matrix operation User Action Use HP BASIC to create the array ARGTOOLAR Argument too large in EXP ERR 49 Explanation The program contains e An argument to the EXP function larger than 88 e An exponentiation operation that results in a number greater than 1E38 User Action Change the EXP argument to be in the valid range or reduce the size of the exponent ARRMUSSAM Arrays must be same dimension ERR 238 Explanation The program attempts to perfor
469. ompile Time Error Messages A 41 IMMMODOPE immediate mode operation requires storage allocation Explanation ERROR An immediate mode statement attempted to allocate storage for example to create a new variable User Action None You cannot create new storage in immediate mode IMMNOTANS immediate mode not valid when ANSI Explanation ERROR An immediate mode statement was typed when in ANSI mode User Action None IMPCNTNOT implied continuation not allowed Explanation ERROR The program contains an implied continuation line after a statement that does not allow implicit continuation for example a DATA statement User Action Use an ampersand amp to continue the statement IMPDECILL implicit declaration of lt name gt illegal in immediate mode Explanation ERROR A new variable was named in an immediate mode statement after a STOP for example PRINT B after a STOP in a program that has no variable named B User Action None You cannot create new variables in immediate mode after a STOP statement IMPDECNOT implied declaration not allowed for lt name gt with EXPLICIT Explanation ERROR A program compiled with the TYPE EXPLICIT qualifier contains an implicitly declared variable User Action Declare the variable explicitly or compile the program without the TYPE EXPLICIT qualifier INACODFOL inaccessible code follows line lt n gt statement lt m gt Explanation WARNING The compiler has d
470. on for example DECLARE RFA CONSTANT User Action Remove the invalid data type You cannot declare constants of the RFA data type ILLEXTPDP lt name gt is illegal as a PDP 11 external name Explanation INFORMATION This error is reported only when the FLAG BP2COMPATIBILITY qualifier is in effect The external name is longer than six characters or contains a non RAD50 character User Action Reduce the length of the name or remove the non RAD50 character Compile Time Error Messages A 37 ILLFRMNAM illegally formed name Explanation ERROR The program contains an invalid user identifier such as a variable constant or function name User Action Change the name to comply with the rules for naming user identifiers See the HP BASIC for OpenVMS Reference Manual for more information ILLFRMNUM illegally formed numeric constant Explanation ERROR The program contains either 1 an invalid E format expression or 2 a numeric constant with a digit that is invalid in the specified radix for example a decimal constant containing a hexadecimal digit User Action Supply a valid E format expression or a constant that is valid in the specified radix ILLGOTO can t GOTO outside current procedure Explanation WARNING The target line number of an immediate mode GOTO statement is outside of the currently compiled procedure User Action None If you RUN a source file containing more than one program unit the curre
471. on Steps into function STEP INTO DEF function Steps into RTL STEP INTO external function or SUB routine Steps into function STEP INTO GOSUB block Steps into RTL 1Unless the subroutine is compiled with the NOSETUP qualifier or equivalent it will appear to step into RTL code because an environment setup RTL routine is normally called as the very first thing of the subroutine 3 6 1 Controlling Symbol References When using the OpenVMS Debugger all HP BASIC variable and label names within a single program unit must be unique otherwise the debugger will be unable to determine the symbol to which you are referring 3 7 Sample Debugging Session This section shows a sample debugging session using a BASIC program that contains a logic error The following program compiles and links without diagnostic messages from either the compiler or the linker However after printing the headers the program is caught in a loop printing the same figures indefinitely 1 10 SAMPLE program for DEBUG illustration 2 DECLARE INTEGER Number 3 Print headers 4 PRINT NUMBER SQUARE SQUARE ROOT 5 PRINT 6 Print loop 7 FOR Number 10 TO 1 STEP 1 8 PRINT Number Number 2 SQR Number 9 Number Number 1 10 NEXT Number 11 PRINT 12 END The following text shows the terminal dialogue for a debugging session which helps locate the error in the program SAMPLE The callouts are keyed to explanatory notes that follow the dialogue U
472. on blocks control the execution of a block of statements e Branching statements such as GOTO and ON GOTO pass control to statements or local subroutines e The EXIT and ITERATE statements explicitly control loops or decision blocks e The SLEEP WAIT STOP and END control statements suspend or halt the execution of your entire program 9 1 Statement Modifiers Statement modifiers are control structures that operate on a single statement Statement modifiers let you execute a statement conditionally or create a loop The following are BASIC statement modifiers IF UNLESS FOR UNTIL WHILE A statement modifier affects only the statement immediately preceding it You can modify only executable statements declarative statements cannot be modified Program Control 9 1 9 1 1 IF Modifier The IF modifier tests a conditional expression If the conditional expression is true HP BASIC executes the statement If it is false HP BASIC does not execute the modified statement but continues execution at the next program statement The following is an example of a statement using the IF modifier PRINT A IF A lt 5 9 1 2 UNLESS Modifier The UNLESS modifier tests a conditional expression HP BASIC executes the modified statement only if the conditional expression is false PRINT A UNLESS A lt 5 This is equivalent to the following PRINT A IF A gt 5 9 1 3 FOR Modifier The FOR modifier creates a loop on a single line T
473. on to a terminal format file as a report PRINT This program creates a daily sales report file named SALES DAT OPEN SALES DAT FOR OUTPUT AS FILE 4 PRINT 4 Salesperson Sales Area Items Sold PRINT 4 INPUT How many salespersons for today s report sales persons FOR I 1 TO sales persons INPUT Salesperson s name s name INPUT Sales area area INPUT Number of items sold items sold PRINT 4 s name area items sold NEXT I g CLOSE 4 END Output This program creates a daily sales report file named SALES DAT How many salespersons for today s report 3 Salesperson s name JONES Sales area NJ Items sold 5 Salesperson s name SMITH Sales area NH Items sold 6 Salesperson s name BAINES Sales area VT Items sold 8 5 14 Simple Input and Output This program first prints a header explaining its purpose then opens a terminal format file on channel 4 After this file is opened the two PRINT statements place an explanatory header followed by a blank line into the file The program then prompts you for the number of salespersons for which data is to be entered The FOR NEXT loop prompts for the name sales area and items sold for each salesperson The FOR NEXT loop executes only as many times as there are salespersons See Chapter 9 for more information about FOR NEXT loops After the data has been entered for each salesperson the program writes this informati
474. on to the terminal format file Because the response to the first question was 3 the FOR NEXT loop executes three times After the last item has been printed to the file the program closes the file and ends When you display the file with the DCL command TYPE you see that the information is printed under the proper headers You can also print the file on a line printer The PRINT statement formats the output in print zones as the PRINT statement does TYPE SALES DAT Salesperson Sales Area Items Sold JONES NJ 5 SMITH NH 6 BAINES VT 8 Simple Input and Output 5 15 6 Arrays An array is a set of data that is ordered in any number of dimensions This chapter describes how to create and use HP BASIC arrays 6 1 Overview of Arrays A one dimensional array is called a list or vector A two dimensional array is called a matrix HP BASIC arrays can have up to 32 dimensions and a specific type of HP BASIC arrays can be redimensioned at run time In addition you can specify the data type of the values in an array by using data type keywords or suffixes The subscript of an element in an array defines that element s position in the array When you create an array you specify e The number of dimensions that the array contains e The range of values for the subscripts in each dimension of the array BASIC arrays are zero based by default that is when calculating the number of elements in a dimension you count from zero to t
475. only a selected group of built in functions For a complete description of all HP BASIC built in functions see the HP BASIC for OpenVMS Reference Manual This chapter also describes user defined functions HP BASIC lets you define your own functions in two ways e With the DEF statement e As separately compiled subprograms external functions DEF function definitions are local to a program module while external functions can be accessed by any program module You create local functions with the DEF statement and optionally declare them with the DECLARE statement You create external functions with the FUNCTION statement and declare them with the EXTERNAL statement For more information about creating external functions with the FUNCTION statement see Chapter 12 Once you create and declare a function you can invoke it like a built in function 10 1 Built In Functions The functions described in this section let you perform sophisticated manipulations of string and numeric data HP BASIC also provides algebraic exponential trigonometric and randomizing mathematical functions Functions 10 1 10 1 1 10 1 1 1 10 1 1 2 Numeric Functions Numeric functions generally return a result of the same data type as the function s parameter For example if you pass a DOUBLE argument to any of the trigonometric functions they return a DOUBLE result If the format of a HP BASIC function specifies an argument of a particular data
476. operating system that runs on the Intel Itanium architecture The following typographic conventions might be used in this manual Ctrl x A sequence such as Ctrl x indicates that you must hold down the key labeled Ctrl while you press another key or a pointing device button PF1 x A sequence such as PF1 x indicates that you must first press and release the key labeled PF1 and then press and release another key or a pointing device button Return In examples a key name enclosed in a box indicates that you press a key on the keyboard In text a key name is not enclosed in a box In the HTML version of this document this convention appears as brackets rather than a box xxi C bold type italic type UPPERCASE TYPE xxii A horizontal ellipsis in examples indicates one of the following possibilities e Additional optional arguments in a statement have been omitted e The preceding item or items can be repeated one or more times e Additional parameters values or other information can be entered A vertical ellipsis indicates the omission of items from a code example or command format the items are omitted because they are not important to the topic being discussed In command format descriptions parentheses indicate that you must enclose choices in parentheses if you specify more than one In command format descriptions brackets indicate optional choices You can choose one or
477. or DESCOMERR error in processing design information Explanation WARNING The design information was syntactically incorrect User Action You should respecify the design information and compile the program again DESIGNTOOOLD DESIGN COMMENT processing routines are too old for the compiler Explanation WARNING The compiler encountered obsolete routines User Action Install a new version of the Language Sensitive Editor for OpenVMS DESOUTRAN destination out of range Explanation FATAL The branch destination in an ON GOSUB statement is greater than 32 767 bytes away from the statement User Action Reduce the distance between the destination and the statement Compile Time Error Messages A 23 DIMOUTRAN dimension is out of range Explanation ERROR The program contains the declaration of an array that specifies a negative number as a dimension User Action Change the dimension to a positive number DIMLSSZERO dimension must be greater than zero Explanation ERROR The number specified for a dimension must be greater than zero User Action Change the number to be greater than zero DIMTOOBIG dimension for array lt name gt must be between 1 and lt number gt Explanation ERROR The number of the dimension specified is greater than the number of dimensions in the array User Action Change the dimension number to be less than or equal to the number of dimensions in the array DIRMUSTBE di
478. or more information about debugging see Chapter 3 Developing HP BASIC Programs 2 7 Remarks e NODEBUG causes the compiler to suppress information for the OpenVMS Debugger and the system run time error traceback mechanism e DEBUG ALL is the same as DEBUG TRACEBACK SYMBOLS e DEBUG NONE is the same as NODEBUG DECIMAL_SIZE d s DECIMAL_SIZE 15 2 default The DECIMAL_SIZE qualifier lets you specify the default size for packed decimal data You specify the total number of digits in the number and the number of digits to the right of the decimal point DECIMAL_SIZE 15 2 is the default This default decimal size applies to all decimal variables for which the total number of digits and digits to the right of the decimal point are not explicitly declared See the HP BASIC for OpenVMS Reference Manual for more information about packed decimal numbers NO DEPENDENCY_DATA NODEPENDENCY_DATA default The DEPENDENCY_DATA qualifier generates a compiled module entity in the CDD DEFAULT for each compilation unit Remarks e A compiled module entity is generated only if CDD Plus Version 4 0 or higher or CDD Repository Version 5 0 or higher is installed on your system and if your current CDD DEFAULT is a CDO format dictionary e You must specify this qualifier if you want INCLUDE FROM CDD and REPORT DEPENDENCY directives to establish dependency relationships e NODEPENDENCY_DATA causes the compiler
479. or example PRINT SOR 2 Output 1 41421 LOG10 Function A logarithm is the exponent of some number called a base Common logarithms use the base 10 The common logarithm of a number n for example is the power to which 10 must be raised to equal n For example the common logarithm of 100 is 2 because 10 raised to the power 2 equals 100 The LOG10 function returns a number s common logarithm The following example calculates the common logarithms of all multiples of 10 from 10 to 100 inclusively FOR I 10 TO 100 STEP 10 PRINT LOG10 I NEXT I END Output 30103 47712 60206 69897 77815 8451 90309 95424 PRPRPRP a j j jl N If you supply a floating point argument to LOG10 the function returns a floating point number of the same data type If you supply an integer argument LOG10 converts it to the default floating point data type and returns a value of that type 10 4 Functions 10 1 1 6 10 1 1 7 EXP Function The EXP function returns the value of e raised to a specified power The following example prints the value of e and e raised to the second power READ A B DATA 1 2 PRINT e RAISED TO THE POWER A EQUALS EXP A PRINT e RAISED TO THE POWER B EQUALS EXP B END Output e RAISED TO THE POWER 1 EQUALS 2 71828 e RAISED TO THE POWER 2 EQUALS 7 38906 If you supply a floating point argument to EXP the function returns a floating point number of the same da
480. or expression User Action Change the argument to the LOC function ILLLOONES illegal loop nesting expecting NEXT lt VARIABLE gt Explanation ERROR The program contains overlapping loops User Action Examine the program logic to make sure that the FOR and NEXT statements for the inside loop lie entirely within the outside loop ILLMATOPEI illegal matrix operation Explanation ERROR The program attempts matrix division The operation is treated as a MAT multiply and the compilation continues User Action Remove the attempted matrix division HP BASIC does not support this operation ILLMCHPDP illegal passing mechanism on PDP 11s Explanation INFORMATION This error is reported only when the FLAG BP2COMPATIBILITY qualifier is in effect A parameter list contains a BY clause that is invalid in PDP 11 BASIC PLUS 2 for example specifying BY DESC for parameters that are not entire arrays or strings User Action See the HP BASIC for OpenVMS Reference Manual for allowable BASIC PLUS 2 parameter passing mechanisms ILLMIDLEN illegal MID assignment length Explanation ERROR The value of the length in the MID statement is either greater than the length of the string or less than or equal to zero User Action Correct the length to be between 1 and the length of the string Compile Time Error Messages A 39 ILLMIDSTRT illegal MID starting value Explanation ERROR The starting value in the MID statement is les
481. or handler typically performs the following functions e Determines which error occurred e Takes appropriate action based on the nature of the error e Clears the error condition with a RETRY CONTINUE END WHEN or END HANDLER statement e Continues program execution when possible e Possibly identifies which program unit or statement caused the error e Resignals errors with EXIT HANDLER when an error cannot be handled for some reason Handlers can be attached to or detached from the statements in the WHEN ERROR protected region An attached handler is delimited by a USE and an END WHEN statement The attached handler immediately follows the protected region of a WHEN ERROR IN block The following example shows an attached handler that traps errors on I O statements division by zero and illegal numbers 15 4 Handling Run Time Errors PROGRAM accident prone DECLARE REAL age accidents rating WHEN ERROR IN Get age INPUT Enter your age age INPUT How many serious accidents have you had accidents rating accidents age PRINT That s rating serious accidents per year USE SELECT ERR Trap division by zero CASE 61 PRINT Please enter an age greater than 0 CONTINUE Get age Trap illegal number CASE 52 PRINT Please enter a positive number RETRY CASE ELSE Revert to default error handling EXIT HANDLER END SELECT END WHEN END PROGRAM A detached handler is defined separately in your program unit It requi
482. ord Indexed Record found Next record in current key order Random access FIND All Record found Unchanged Note that a random access FIND operation locates the specified record and makes it the current record but the next record pointer does not change You can specify an ALLOW clause to the FIND statement if you have opened the file with ACCESS MODIFY or ACCESS WRITE and have specified UNLOCK EXPLICIT The ALLOW clause lets you control the type of lock that RMS puts on the records you access ALLOW NONE specifies that no other users can access this record this is the default ALLOW READ lets other users read the record however they cannot perform UPDATE or DELETE operations to this record ALLOW MODIFY specifies that other users can both read and write to this record This means that other access streams can perform GET DELETE or UPDATE operations to the specified record You can also specify a WAIT clause to the FIND statement this clause allows you to wait for a record to become available in the event that it is currently locked by another process In addition you can specify a REGARDLESS clause this clause allows you to read a locked record For more information about the WAIT and REGARDLESS clauses see Section 13 6 9 Reading Records The GET statement moves a record from a file to a record buffer and makes the data available for processing GET statements are valid on sequential relative and indexed files You should not use
483. ory SYSSCOMMON CDDPLUS SMITH ADDRESS 1 FIELD ADDRESS REC 1 RECORD CITY 1 FIELD EXAMPLE1 1 CDDSCOMPILED MODULE FIRST NAME 1 FIELD LAST NAME 1 FIELD STATE 1 FIELD FIELD ZIP_CODE 1 You can use the CDO SHOW USES command to find out what programs use a dictionary definition For example CDO gt SHOW USES ADDRESS REC Owners of SYSSCOMMON CDDPLUS SMITH ADDRESS REC 1 SYSSCOMMON CDDPLUS SMITH EXAMPLE1 1 Type CDD COMPILED MODULE via CDD COMPILED DEPENDS ON T You can also use CDO to find out what dictionary definitions a program uses For example CDO gt SHOW USED BY EXAMPLE1 Members of SYSSCOMMON CDDPLUS SMITH EXAMPLE1 1 EX1 Type CDD FILE via CDD IN FILE SYSSCOMMON CDDPLUS SMITH ADDRESS REC 1 Type RECORD via CDDSCOMPILED DEPENDS ON Using CDD Repository with BASIC 21 9 21 4 Creating Relationships for Referenced Dictionary Entities The compiler can create a relationship between a compiled module entity and any dictionary entity that a program references such as a VAX Rdb VMS database or a form definition The referenced dictionary entity is not copied to the program Instead the compiled program references the dictionary entity at run time or with the help of a preprocessor To create relationships for referenced dictionary entities in a BASIC program use the 7 REPORT DEPENDENCY lexical directive in the source program and specify the DEPENDENCY_DATA qualifier when you compile the
484. ou can use subtitle text to identify parts of the source program As in TITLE the text you use in SBTTL must be a quoted string not exceeding 31 characters Note however that subtitle information appears on listing pages that contain the actual source code The following example shows the use of both TITLE and SBTTL directives The first line of the listing s first page contains Payroll Program and the second line contains Constant Declarations When BASIC encounters the SBTTL directive the second line on each subsequent page becomes Subroutines When BASIC encounters the SBTTL directive the second line on each subsequent page becomes Error Handler TITLE Payroll Program SBTTL Constant Declarations SBTTL Subroutines SBTTL Error Handler Compiler Directives 16 3 You can use multiple TITLE directives in a single source file however whenever BASIC encounters a TITLE directive the SBTTL information is set to the null string Therefore if you want to display subtitle information each new TITLE directive should be accompanied by a new SBTTL directive 16 2 2 IDENT Directive The IDENT directive identifies the version of a program module The identification text must be a quoted string of up to 31 characters The information contained within the identification text appears in the listing file and the object module Thus the map file created by the OpenVMS Linker also contains th
485. ou requested cannot be performed on the specified device For example output cannot be dislayed on a device that is for input only User Action Specify the device ID for a device with the appropriate compatibility Device types are listed in Programming with VAX BASIC Graphics DEVOUTMET Device is an output metafile ERR 269 Explanation The specified device is an output metafile device type 2 User Action Specify the device ID for a device other than an output metafile DEVTYPNOT Device type is not supported ERR 267 Explanation The specified device type is not supported by Compaq GKS for OpenVMS User Action Specify an alternative device type Standard supported device types are listed in Programming with VAX BASIC Graphics and in the Compaq GKS for OpenVMS documentation Verify with your system manager that support for the specified device has been installed Also verify that the Compaq GKS for OpenVMS startup command procedure has properly executed B 6 Run Time Messages DIFUSELON Differing use of LONG WORD or SINGLE DOUBLE qualifiers ERR 229 Explanation The main and subprograms were compiled with different LONG WORD modes This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Recompile one of the programs with the same qualifier as the other DIMOUTRAN Dimension number out of range ERR 195 Explanation The upper or lower bound of the
486. p PROGRAM EXAMPLE1 SINCLUDE FROM CDD CDDSTOP SMITH ADDRESS REC RECORD ADDRESS REC STRING FIRST NAME 20 STRING LAST NAME 30 STRING ADDRESS 40 STRING CITY 20 STRING STATE 2 DECIMAL 5 0 ZIP CODE END RECORD DECLARE ADDRESS REC TEST RECORD UNSPECIFIED TEXT TEXT TEXT TEXT TEXT PACKED DECIMAL INPUT First name TEST RECORD FIRST NAME INPUT Last name TEST RECORD LAST NAME INPUT Address TEST RECORD ADDRESS INPUT City TEST RECORD CITY INPUT State TEST RECORD STATE INPUT Zip code TEST RECORD ZIP CODE 21 8 Using CDD Repository with BASIC 11 12 13 PRINT TEST RECORD FIRST NAME TEST RECORD LAST NAME PRINT TEST RECORD ADDRESS PRINT TEST RECORD CITY TEST RECORD STATE TEST RECORD ZIP_CODE With a CDO format dictionary you can also instruct the dictionary to create and maintain a formal relationship between the record description and the compiled module entity that represents your program in the dictionary This is known as a CDD COMPILED_DEPENDS_ON relationship Specify the DEPENDENCY_DATA qualifier when compiling a program as follows BASIC DEPENDENCY DATA EX1 BAS If you specify the DEPENDENCY_DATA qualifier the compiled module entity is created and updated to reflect that your program uses that record If you want to change the data definition CDO allows you to find out what programs depend on it before doing so For example CDO gt DIRECTORY Direct
487. p address address length NEXT At the start of program execution the storage for badge is the first 4 bytes of emp_buffer the storage for social_sec_num is equal to 9 bytes and together name_length and address_length are equal to 2 bytes The FILL keyword reserves 60 additional bytes of storage The MAP DYNAMIC statement defines the variables emp_name and emp_address whose positions and lengths will change at run time When executed the REMAP statement defines the FILL area to be equal to emp_fixed_info and defines the positions and lengths of emp_name and emp_address When you specify a static string variable it must be either a variable declared in a MAP or COMMON statement or a parameter declared in a SUB FUNCTION PICTURE or DEF The actual parameter passed to the procedure must be a static string variable defined in a COMMON MAP or RECORD statement The following example shows the use of a static string variable as a parameter declared in a SUB The MAP DYNAMIC statement specifies the input parameter input_rec as the string to be dynamically defined with the REMAP statement In addition the MAP DYNAMIC statement specifies a string array A whose elements will point to positions in input_rec after the REMAP statement is executed The REMAP statement defines the length and position of each element contained in array A The FOR NEXT loop then assigns each element contained in array A into array item the target array 7 14 Data D
488. penVMS 15 15 handling RMS 15 16 in a function 15 22 NOTBASIC 15 12 OPTION HANDLE statement 15 11 pending 15 1 15 18 run time 15 1 severity levels 15 11 severity of 15 1 trapping 15 1 to 15 23 Index 6 Errors cont d types of 15 1 Error trapping 15 1 to 15 23 ERT function 15 14 EVALUATE debugger command 3 13 EXAMINE debugger command 3 11 Exception handling 15 1 to 15 23 Exclamation point 4 5 Execution start resume in debugging 3 5 EXIT FUNCTION statement 12 4 specifying expression with 12 4 EXIT HANDLER statement 15 10 EXIT PROGRAM statement 12 11 EXIT statement 9 14 to 9 16 EXIT SUB statement 12 3 EXP function 10 5 Exponential format with asterisk fill 14 11 with PRINT USING statement 14 10 Expression See Address expression See Language expression Expressions 4 13 mixed mode 7 3 Extended fields with PRINT USING statement 14 15 External routines calling 19 5 19 7 declaring 19 6 EXTERNAL statement 12 3 12 4 19 6 specifying data type of parameters 12 4 specifying data type of return value 12 3 12 4 specifying parameter passing mechanism in 12 4 type checking with 12 5 Extracting data definitions 21 7 Extracting record definitions 21 9 F File I O advanced 18 1 to 18 18 File input output 13 1 to 13 43 File name specifying in the OPEN statement 18 1 File operations 13 11 File organization 13 2 indexed 13 4 relative 13 3 sequential 13 3 terminal format
489. peration 191 ILLTFFOPE Illegal terminal format file operation 192 ILLWAIVAL Illegal wait value 193 DEADLOCK Detected deadlock while waiting for GET or FIND 194 NOTBASIC Not a BASIC error continued on next page B 34 Run Time Messages Table B 1 Cont BASIC Run Time Errors Error Number Explanation 195 DIMOUTRAN Dimension number out of range 196 REMSTRNOT REMAP string is not static 197 ARRTOOSMA Array too small 226 GKSNOTINS DEC GKS FOR VMS is not installed 227 STRTOOLON String too long 228 RECATTNOT Record attributes not matched 229 DIFUSELON Differing use of LONG WORD qualifiers 238 ARRMUSSAM Arrays must be same dimension 239 ARRMUSSQU Arrays must be square 240 CANCHAARR Cannot change array dimensions 245 ILLEXIDEF Illegal exit from DEF 246 ERRTRANEE ERROR trap needs RESUME 247 ILLRESSUB Illegal RESUME to subroutine 250 NOTIMP Not implemented 252 FILACPFAI FILE ACP failure 253 DIRERR Directive error 256 ECHTYPNOT Prompt echo type not supported 257 ILLTRANUM Illegal transformation number 258 ILLPICOPE Illegal picture operation 259 CLIPONOFF Clipping must be ON or OFF 260 TRANOTODIF Transformation numbers are not different 261 COLNOTCON Color indices are not contiguous 262 ILLARESTY Illegal area style 263 ILLTEXJUS Illegal text justification 264 ILLTEXPRE Illegal text precision 265 ILLTEXPAT Illegal text path 266 ILLDEVID Illegal device identification number 267 DEVTYPNO
490. planation A subprogram was compiled with a different SCALE factor than that of the calling program This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Recompile one of the programs with a scale factor that matches the other SIZRECINYV Size of record invalid ERR 156 Explanation The program contains a COUNT or RECORDSIZE specification that is invalid because e COUNT equals zero e COUNT exceeds the maximum size of the record e COUNT conflicts with the actual size of the current record during a sequential file UPDATE on disk e COUNT does not equal the record size for fixed format records B 26 Run Time Messages e You specified a record size in the OPEN statement that was unequal to the actual record size established when the file was created User Action Supply a valid COUNT value in the PUT or UPDATE statement or a valid RECORDSIZE in the OPEN statement whichever is applicable STO Stop ERR 123 Explanation The program executed a STOP statement This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE INFO or a greater severity User Action Continue execution by typing CONTINUE or terminate execution by typing EXIT STRLENZER string length is zero ERR 288 Explanation A graphics statement references a null string where a null string is illegal User Action Adjust the string length so tha
491. ple 5 Return Return These responses assign the value 5 to variable A and zero to variable B In contrast if you provide more values than there are variables BASIC ignores the excess In the following example BASIC ignores the extra value 8 You can type multiple values if you separate them with commas Because commas separate variables in the PRINT statement BASIC prints each variable at the start of a print zone 1 The SET NO PROMPT statement turns off the optional question mark see Section 5 1 1 3 5 2 Simple Input and Output INPUT A B PRINT A B END Output 5 67778 5 6 7 Cc C If you name a numeric variable in an INPUT statement you must supply numeric data If you supply string data to a numeric variable BASIC signals Illegal number ERR 52 If you supply a floating point number for an integer variable BASIC signals Data format error ERR 50 If you name a string variable in an INPUT statement you can supply either numbers or letters but BASIC treats the data you supply as a string Because digits and a decimal point are valid text characters numbers can be interpreted as strings For example INPUT Please type a number A PRINT A Output Please type a number 25 5 25 5 BASIC interprets the response as a 4 character string instead of as a numeric value You can type strings with or without quotation marks However if you want to input a string cont
492. plicitly declared See the HP BASIC for OpenVMS Reference Manual for more information about integer data types Developing HP BASIC Programs 2 9 NO LINES NOLINES default The LINES qualifier makes line number information available for the ERL function and the BASIC error reporter Remarks e NOLINES causes line number information to be unavailable for the ERL function and the HP BASIC error reporter Specifying NOLINES makes your program run faster and reduces program size However specifying NOLINES causes the following restrictions to be in effect You cannot use the ERL function No BASIC line number is given in run time error messages NO LISTING file spec LISTING default in batch mode NOLISTING default in interactive mode The LISTING qualifier causes BASIC to produce a source listing file Remarks e LISTING file spec produces a file with an explicit file specification Omitting the file spec produces a listing file with the same name as its corresponding source file and a file type of LIS e All other file specification attributes depend on the placement of the qualifier in the command See the OpenVMS User s Manual for more information e LISTING only controls whether or not the compiler produces a listing file and is the default in batch mode e SHOW controls which parts of the listing are produced e NOLISTING specifies that no source listing file be produced and is the defa
493. program Compile Time Error Messages A 59 MULNOTBP2 multiple program units per module not BASIC PLUS 2 compatible Explanation INFORMATION A program compiled with the FLAG BP2COMPATIBILITY qualifier contains more than one program unit BASIC PLUS 2 does not allow more than one program unit in a single file User Action Separate the program into individual program units and compile the units separately MULOPTBAS multiple OPTION BASE statements not ANSI Explanation ERROR A program compiled with the ANSI_STANDARD qualifier contains more than one OPTION BASE statement User Action Specify the OPTION BASE statement only once per program MULPRONOT multiple program units per module not ANSI Explanation INFORMATION A program compiled with the ANSI_ STANDARD qualifier contains more than one program unit User Action Rewrite the program converting the subprograms to subroutines MULSTAPER multiple statements per line not ANSI Explanation INFORMATION A program compiled with the ANSI_ STANDARD qualifier contains more than one statement on a line User Action Change the program so that each statement has its own line number MULTDEF multiple definition of lt name gt Explanation WARNING A variable is declared in more than one declarative statement User Action Make sure that the variable is declared only once NAMNOTREC name lt name gt is not of a RECORD component Explanation ERROR A REC
494. program reverts to default error handling Outer handlers are invoked when an inner handler executes an EXIT HANDLER statement When there are no more outer handlers and the outermost handler executes an EXIT HANDLER statement program control reverts to the handler associated with the calling routine For example SUB LIST AS WHEN ERROR USE sub handler OPEN A FOR INPUT AS FILE 12 Get data LINPUT 12 BS PRINT BS GOTO Get data END WHEN HANDLER sub handler Trap end of file IF ERR lt gt 11 THEN EXIT HANDLER END IF END HANDLER CLose up CLOSE 12 END SUB 15 18 Handling Run Time Errors You can call a subprogram while an error is pending however if you do the subprogram cannot resignal an error back to the calling program If the subprogram tries to resignal an error HP BASIC signals Improper error handling and program execution terminates The following rules apply to error handling in function definitions e DEF and DEF function definitions cannot appear within a protected region However protected regions can be contained within the function definitions e To trap errors while a DEF function is active include protected regions inside the DEF function If you do this the associated handler remains in effect until your program leaves the protected region or the DEF function For example WHEN ERROR IN Invoke _ def AS FNIN_PUTS PROMPT USE PRINT ERROR ERT ERRS IF ERN FNIN
495. qualifier 2 17 Variants CDD Repository 21 14 Vector 6 1 Virtual array files 13 14 Virtual files 13 4 VMSSTATUS function 13 33 to 13 34 15 15 Index 16 W WAIT clause 13 18 138 25 Warning errors 15 1 WARNINGS qualifier 2 18 WHEN ERROR constructs 15 2 to 15 20 attached handler 15 2 CONTINUE to target 15 8 exiting handler 15 6 nested 15 10 to 15 11 protected region 15 2 with CONTINUE statement 15 8 with EXIT HANDLER statement 15 10 with RETRY statement 15 8 WHILE NEXT loops 9 6 to 9 7 WHILE modifier 9 1 WORD data type 4 7 subtypes 4 7 Z Zero fill with asterisk fill 14 11
496. r OPTION HANDLE ERROR EXTERNAL LONG CONSTANT BAS K_RECNOTFOU BAS K_RECBUCLOC DECLARE LONG Final _ status MAP Rec_buffer amp STRING Rec_key 5 amp STRING Rest_of record 20 Final status 1 WHEN ERROR USE Global handler OPEN My database FOR INPUT AS FILE 1 INDEXED FIXED ACCESS READ MAP Rec buffer PRIMARY Rec key Get key INPUT Record to retrieve Rec key WHEN ERROR IN GET 1 8 KEY 0 EQ Rec key PRINT Rest_of record MOH oe USE SELECT ERR CASE BASSK RECNOTFOU PRINT Record not found CONTINUE Get_key Handling Run Time Errors 15 15 15 2 5 6 CASE BAS K RECBUCLOC SLEEP 2 RETRY CASE ELSE EXIT HANDLER END SELECT END WHEN END WHEN HANDLER Global handler Final status VMSSTATUS END HANDLER END PROGRAM Final status Determining RMS Error Information The RMSSTATUS function lets you determine which RMS error caused a resulting HP BASIC error You must specify an open channel as the first parameter to RMSSTATUS If this channel is not open the error I O channel not open ERR 9 is signaled The second parameter to the function lets you specify either STATUS or VALUE this parameter is optional If you do not specify the second parameter RMSSTATUS returns the STATUS value by default STATUS represents the RMS STS field and VALUE corresponds to the RMS STV field The following example shows an error handler that prints both the status and the value of any RMS error WHEN
497. r Action Change the number of fractional digits in CDD Repository to be less than or equal to the total number of digits CDDRECFOR CDD Repository record format is not fixed Explanation ERROR CDD Repository supports both variable and fixed length records HP BASIC supports only fixed length records User Action Change the CDD Repository record definition to specify fixed length A 14 Compile Time Error Messages CDDRECNAM record from CDD Repository does not have a record name Explanation ERROR HP BASIC uses the field name of the outermost structure to name the record and therefore cannot include a CDD Repository record that does not provide a record name User Action Change the CDD Repository record definition to provide a field name for the outermost structure of the record CDDSCAERR decimal scale of lt scale factor gt is out of range for lt field gt from CDD Repository Explanation ERROR The scale factor for a packed decimal CDD Repository field is greater than the number of digits in the field or less than zero User Action Change the scale factor in the CDD Repository definition CDDSCAZER scale 0 specified for CDD Repository field lt field name gt Explanation INFORMATION A CDD Repository field specifies no scale factor for a D_floating field but the HP BASIC program specifies a nonzero scale factor User Action Use a scale factor of zero in the HP BASIC program CDDSTRONLY not allowed on
498. r Action None Compile Time Error Messages A 71 PRICDDERR prior severe CDD Repository error Explanation ERROR There have been one or more severe CDD Repository errors and this may be the reason for the following errors User Action Recompile the program after correcting the first errors related to CDD Repository PRIUSICLA PRINT USING clause must be a string expression Explanation ERROR A PRINT USING statement specifies a numeric format string User Action Supply a valid format string PRIUSICON PRINT USING conflicts with RECORD clause Explanation ERROR A PRINT USING statement contains a RECORD clause User Action Remove the RECORD clause or use the PRINT statement instead of PRINT USING PROSTRNES program structures nested too deeply Explanation FATAL The program contains too many nested block constructs for example DEF function definitions User Action Reduce the number of nested block constructs PROTOOBIG program too big to compile Explanation FATAL tThe program is too big User Action Recode the program as two or more modules PROWHINOT exit from PROGRAM while not in a main program Explanation ERROR An EXIT PROGRAM statement was found in a program unit that is not a main program User Action Use the type of EXIT appropriate to the program unit QUALERR unknown qualifier lt name gt Explanation ERROR An attempt was made to enter an invalid qualifier to a SET LOCK o
499. r COMMON with the same name exists in more than one program module but the size of the areas differs User Action Make the size of the COMMON or MAP areas equal in size in all modules COMMAPOVF COMMON MAP lt name gt is too large Explanation ERROR The program contains a MAP or COMMON longer than 2 31 1 longwords User Action Reduce the length of the COMMON or MAP CONCOMSYN conditional compilation cannot be used with SYNTAX Explanation FATAL The SYNTAX_ CHECKING qualifier is in effect when a program line containing the IF THEN ELSE or WEND IF lexical directive was entered User Action Turn off syntax checking before entering a program line containing the IF THEN ELSE or END IF lexical directive CONDATSPC conflicting data type specifications Explanation ERROR The program contains a declarative statement containing two or more consecutive and contradictory data type keywords for example DECLARE REAL BYTE User Action Remove one of the data type keywords or make sure that the keywords refer to the same generic data type For example DECLARE REAL SINGLE is valid CONEXPREQ constant expression required Explanation ERROR A statement specifies a variable built in function reference or exponentiation where a constant is required User Action Supply an expression containing only literals or declared constants or remove the exponentiation operation CONTARNOT CONTINUE target not
500. r COMPILE command User Action Enter the SET LOCK or COMPILE command with the correct qualifier A 72 Compile Time Error Messages RADNOTSUP radix not supported Explanation ERROR A literal constant specifies a radix For example in the following DECLARE statement H is an invalid radix specifier 10 DECLARE LONG CONSTANT A H 111 User Action Specify a valid radix See the HP BASIC for OpenVMS Reference Manual for a list of the radices HP BASIC allows REAACCINC READ access inconsistent with FOR OUTPUT Explanation ERROR An OPEN statement specifies FOR OUTPUT and ACCESS READ User Action FOR OUTPUT specifies that a new file is created ACCESS READ specifies that the program can only read the file If you want to create a new file remove the ACCESS READ clause if you want read only access to a file specify FOR INPUT READERR error reading lt file name gt Explanation ERROR An error was detected in attempting to read a file User Action Supply a valid file specification or take corrective action based on the associated message REAWITDAT READ without DATA statement Explanation ERROR The program contains a READ statement and there are no DATA statements User Action Supply a DATA statement or remove the READ statement RECENTARR RECORD entire array must not have subfields specified Explanation ERROR A RECORD component reference specifies an array before the end of the component path for exampl
501. r declarative statements see Section 4 5 2 to name and type your program values Following are the data types you can specify e Integer INTEGER e Floating point REAL e String STRING e Packed Decimal DECIMAL e Record File Address RFA Within the INTEGER and REAL data types there are further subdivisions BYTE WORD LONG or QUAD for INTEGER and SINGLE DOUBLE GFLOAT SFLOAT TFLOAT or XFLOAT for REAL Choosing one of these subtypes lets you control the following e The amount of storage required for the value its container size e The range and precision that the value can accept For more information about data types see Chapter 8 4 5 1 Implicit Data Typing With implicit data typing a data type for a variable is created and specified the first time you reference it You specify the data type of the variable by a suffix on the variable name as follows e A percent sign suffix specifies the INTEGER data type e A dollar sign suffix specifies the STRING data type e Any other ending character specifies a variable of the default data type The default data type is SINGLE on Alpha BASIC and SFLOAT on 164 BASIC However you can specify your own default at DCL command level or with the OPTION statement in your program For more information about establishing default data types see Chapter 2 as well as the OPTION statement in the HP BASIC for OpenVMS Reference Manual The first time the variable is referen
502. r has given too many items in response to the INPUT statement This error is only signaled for ANSI INPUT User Action Supply the correct number of items to the INPUT statement or change the INPUT statement TRANOTODIF Transformation numbers are not different ERR 260 Explanation The same transformation number is used twice in the SET INPUT PRIORITY statement User Action Specify two different transformations in the SET INPUT PRIORITY statement UNEFILDAT unexpired file date ERR 179 Explanation The program attempts to delete a file whose expiration date has not yet passed User Action None UNINUMNOT Unit number is not defined for the device ERR 282 Explanation The specified unit is a method that is not supported by the device The default unit is 1 User Action Verify the supported units for the device and specify a valid unit UNKGKSERR Unknown DEC GKS FOR VMS error ERR 286 Explanation A graphics error has occurred that is not mapped to a HP BASIC error message User Action Use VMSSTATUS to access the text of the Compaq GKS error message Run Time Messages B 29 USEABOINP User aborted input locate point cancelled ERR 293 Explanation The middle mouse button was pressed during the execution of a graphics input statement that uses a mouse to enter points for example LOCATE POINT The pressing of the middle mouse button aborts the graphics input statement in progress and the data in the va
503. r programs You cannot execute a shareable image with the DCL command RUN When a program is linked with a shareable image the required shareable image code is not included in the created executable image on the disk This code is included by the image activator at run time Therefore many programs can reside on disk and be bound with a particular shareable image and only one physical copy of that shareable image file needs to exist on disk If a shareable image has been installed using the OpenVMS Install utility you conserve physical memory and potentially reduce paging I O Many processes can include the physical memory pages of an installed shareable image in their address space This reduces the requirements for physical memory Paging occurs when a process attempts to access a virtual address that is not in the process working set When this page fault occurs the page is either in a disk file in which case paging I O is required or is already in physical memory If a page fault occurs for a shared page the shared page may already be resident in memory and no paging I O is required 20 4 Libraries and Shareable Images 20 4 1 Accessing Shareable Images To access a shareable image follow these steps 1 4 5 Write and compile a program unit that is to be inserted into a shareable image Create an options file required for the link operation Link the program with the SHAREABLE qualifier and specify the options fi
504. r s Modifier error Can t compile statement Expression too complicated Inconsistent function usage Illegal DEF nesting FOR without NEXT NEXT without FOR DEF without FNEND FNEND without DEF Literal string needed B 38 Run Time Messages continued on next page Table B 2 Cont Errors Not Generated by HP BASIC Number Text 98 Syntax error 99 String is needed 100 Number is needed 106 Inconsistent subscript use 107 ON statement needs GOTO 108 End of statement not seen 109 What 110 Bad line number pair 111 Not enough available memory 112 Execute only file 113 Please use the run command 114 Can t CONTinue 115 File exists RENAME REPLACE 117 Matrix or array without DIM 118 Bad number in PRINT USING 119 Illegal in immediate mode 120 PRINT USING buffer overflow 121 Illegal statement 125 Wrong math package 135 Illegal usage 140 Index not initialized 163 No file name 165 Cannot position to EOF 167 Illegal record format 169 unused 172 Record lock failed 180 No support for operation in task 182 Network operation rejected 184 Unaligned REMAP variable continued on next page Run Time Messages B 39 B 40 Table B 2 Cont Errors Not Generated by HP BASIC Number Text 188 UNLOCK EXPLICIT requires RECORDSIZE 512 198 225 unused 230 No fields in image 231 Illegal string image 232 Null image 233 Illegal numeric image 234 Numeric image fo
505. r string 235 String image for numeric 236 TIME limit exceeded 237 First arg to SEG greater than second 241 F loating overflow 242 Floating underflow 243 CHAIN to nonexistent line number 244 Exponentiation error 248 Illegal return from subroutine 249 Argument out of bounds 251 Recursive subroutine call 254 255 unused 294 300 unused Run Time Messages C Optional Programming Productivity Tools This appendix provides an overview of optional programming productivity tools These tools are not included with the HP BASIC software they must be purchased separately Using these tools can increase your productivity as an HP BASIC programmer The following products are briefly described in this appendix e Digital Language Sensitive Editor for OpenVMS LSE and Digital Source Code Analyzer for OpenVMS SCA Section C 1 e Oracle CDD Repository Section C 2 e Database Management System DBMS Section C 3 e Digital Test Manager for OpenVMS Section C 4 e Digital Code Management System for OpenVMS CMS Section C 5 For more information on using these tools see the listed documentation at the end of each section For information about how to purchase these tools contact your HP sales representative C 1 Language Sensitive Editor LSE and Source Code Analyzer SCA The Digital Language Sensitive Editor for OpenVMS LSE and the Digital Source Code Analyzer for OpenVMS SCA must be purchased separate
506. r with an error handler Run Time Messages B 23 PROLOSSOR Internal error in BASIC Run Time Library Please submit an SPR ERR 103 Explanation A consistency check in the HP BASIC run time support failed Program execution is aborted This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action This error should never occur Submit a Software Performance Report PROVIO Protection violation ERR 10 Explanation The program attempted to read or write to a file whose protection code did not allow the operation User Action Use a different file or change the file s protection code or the attempted operation RECALREXI Record already exists ERR 153 Explanation An attempted random access PUT on a relative file has encountered a pre existing record User Action Specify a different record number for the PUT or delete the record RECATTNOT Record attributes not matched ERR 228 Explanation A RECORDTYPE clause specifies record attributes that do not match those of the file User Action Change the RECORDTYPE attribute to match that of the file RECBUCLOC Record bucket locked ERR 154 Explanation The program attempts to access a record or bucket that has been locked by another program User Action Retry the operation RECFILTOO Record on file too big ERR 157 Explanation The specified record is longer than the input buffer User Action I
507. ram declaration specified a simple variable or vice versa User Action Change the actual parameter list to match the declared parameter list or vice versa PARTYPREQ parameter type specification required with EXPLICIT Explanation ERROR In a program compiled with TYPE EXPLICIT no data type keyword is specified for a parameter User Action Supply a data type keyword for the parameter There are no default data types when you compile a program with TYPE EXPLICIT PASMECDEF passing mechanism not allowed for DEF Explanation ERROR A DEF function declaration specifies a passing mechanism for a parameter User Action Remove the passing mechanism clause PASMECDIS passing mechanism disagrees with declaration Explanation ERROR The CALL or invocation of a routine specifies a different passing mechanism for a parameter than that specified when the routine was declared User Action Remove the BY clause specified in the CALL or invocation HP BASIC automatically passes parameters with the passing mechanism specified when the routine was declared Compile Time Error Messages A 69 PASMECNOT passing mechanism not allowed for lt item gt Explanation ERROR A program specifies a passing mechanism in a context other than the invocation or declaration of an external subprogram User Action Remove the passing mechanism clause PASWITNO lt name gt has a passing mechanism specified with no parameter list Explanation WA
508. ransfer control you cannot transfer control into a different program module JMPUNRLIN jump to unreferenceable line number lt number gt Explanation ERROR A RESUME GOSUB or GOTO statement attempts to transfer control to a CASE statement User Action Label or number the SELECT statement and transfer control to the beginning of the SELECT CASE block KEYCANNOT key lt name gt in MAP lt map name gt cannot be a dynamic variable Explanation ERROR A KEY clause in an OPEN statement specifies a variable declared as dynamic in a MAP DYNAMIC statement User Action Specify a static variable in the KEY clause that is declare the variable in a MAP statement not a MAP DYNAMIC statement KEYIS_NEE key is needed for indexed files Explanation ERROR The program attempts to open an indexed file for output and the PRIMARY KEY clause is missing User Action Supply a PRIMARY KEY clause KEYMUSBE key must be either word longword quadword string decimal record or group Explanation ERROR A FIND or GET statement on an indexed file contains a key specification that is not a WORD LONG QUAD STRING DECIMAL or an 8 byte RECORD or GROUP expression User Action Change the key specification to be a WORD LONG QUAD STRING DECIMAL or an 8 byte RECORD or GROUP expression A 48 Compile Time Error Messages KEYMUSTBE key lt vbl name gt in map lt map name gt must be either word longword quadword string decimal re
509. rating system for example an OpenVMS RTL routine is called Lib FAO STARLET OLB An object module library containing the object files used to create the shareable image version of the OpenVMS RTL and other less frequently used procedures If program symbols remain unresolved after the OpenVMS Linker searches IMAGELIB OLB the linker then searches this library The linker searches modules in the following order 1 Modules and libraries specified in the LINK command line in the order given 2 User supplied libraries logicals of the form LNK LIBRARY and LNK LIBRARY_1 through LNK LIBRARY_999 3 Images contained in IMAGELIB OLB 4 Modules contained in STARLET OLB The linker only includes references to needed shareable images in the image being created You can use the NOSYSSHR qualifier to the LINK command to suppress the linker s search of RTL shareable images Similarly you can use the NOSYSLIB qualifier to suppress the linker s search of both RTL shareable images and STARLET OLB The linker searches user supplied libraries before searching the default system library If one of your modules has the same name program symbol as an OpenVMS System Service or an RTL routine the linker includes your module in the resulting image rather than the system service or RTL routine 20 2 Libraries and Shareable Images 20 3 Creating User Supplied Object Module Libraries 20 3 1 You create a user supplied object module libr
510. ray to a different number of dimensions User Action Change the arrays dimensions in the DIM or MAT statement CANFINFIL Cannot find file or account ERR 5 Explanation The specified file or directory is not present on the device User Action Supply a valid file specification CANINVMAT Cannot invert matrix ERR 56 Explanation The program attempts to invert a single dimension matrix User Action Supply a matrix of the proper form for inversion Run Time Messages B 3 CANOPEFIL Cannot open file ERR 162 Explanation The program attempts to open a file that cannot be opened User Action Use VMSSTATUS to determine the RMS failure that caused the error CLIPONOFF Clipping must be set to ON or OFF ERR 259 Explanation Valid strings for the SET CLIP statement are ON and OFF User Action Change the string to either ON or OFF COLNOTCON Color indices are not contiguous ERR 261 Explanation The color indices on the device you are using are not contiguous User Action Unlike most devices all color indices between zero and the number returned by the ASK MAX COLOR statement are not available on this device COONOTNDC Coordinates are not within NDC space ERR 273 Explanation The boundaries of NDC space are 0 1 0 1 coordinates must be within this range User Action Supply coordinates with values from 0 to 1 Make sure that the minimum value of x is less than the maximum value of x and
511. reakpoint If you set a tracepoint the path of execution through that tracepoint will be monitored If you set a watchpoint execution will be suspended when the value of the watched variable changes You can also use the GO command to test for an exception condition or an infinite loop If an exception condition that is not handled by your program occurs the debugger will take over and display the DBG gt prompt so that you can issue commands If you are using screen mode the pointer in the source display will indicate where execution stopped You can then use the SHOW CALLS command see Section 3 4 2 to identify the currently active routine calls the call stack In the case of an infinite loop the program will not terminate so the debugger prompt will not reappear To obtain the prompt interrupt the program by pressing Ctrl Y and then issue the DCL command DEBUG You can then look at the source display and a SHOW CALLS display to locate the PC STEP Command The STEP command which you can use either by entering STEP or by pressing KPO allows you to execute a specified number of source lines or instructions or to execute the program to the next instruction of a particular kind for example to the next CALL instruction By default the STEP command executes a single source line at a time In the following example the STEP command executes one line reports the action stepped to and displays the line number 27 and sour
512. record size if specified e Must include at least the primary key field The following program updates a specified record on an indexed file MAP UPD STRING Enrdat 8 LONG Part num Sh num REAL Cost OPEN REC ING FOR INPUT AS FILE 83 amp INDEXED MAP UPD PRIMARY KEY Part num INPUT Part number to update A Loop WHILE 1 GET 8 KEY 0 EQ A INPUT Revised Cost is Cost UPDATE 8 INPUT Next Record A IF A 0 THEN EXIT Loopl END IF NEXT CLOSE 8 END If the new record either omits one of the old record s alternate key fields or changes one of them the OPEN statement must specify a CHANGES clause for that key field when the file is created Otherwise BASIC signals the error Key not changeable ERR 130 Controlling Record Access When you open a file BASIC allows you to specify how you will access the file and what types of access you will allow other running programs while you have the file open File Input and Output 13 23 If you open a file for read access only ACCESS READ BASIC by default allows other programs to have unrestricted access to the file You can restrict access with an ALLOW clause only if the file s security constraints allow you write access to the file BASIC by default prevents access by other programs to any file you open with ACCESS WRITE ACCESS MODIFY or ACCESS SCRATCH sequential files only This default action is equivalent to specifying the OPEN statement
513. rective must be only item on line Explanation ERROR The program contains a compiler directive that is not the only item on the line User Action Place the directive on its own line DIRNOTIMM directive not valid in immediate mode Explanation ERROR A compiler directive was typed in the VAX BASIC Environment User Action None Compiler directives are invalid in immediate mode DIVBY_ZER division by zero Explanation WARNING The value of a number divided by zero is indeterminate User Action Change the expression so that no expression is divided by the constant zero DRAWITREQ DRAW WITH clause requires 4X4 matrix Explanation ERROR A user matrix is specified in a DRAW statement WITH clause where a two dimensional matrix with lower bounds 0 and upper bounds 4 in both dimensions is required User Action Declare the matrix to be a two dimensional matrix with lower bounds 0 and upper bounds 4 in both dimensions A 24 Compile Time Error Messages DUPCLASPE duplicate clause specified Explanation ERROR A duplicate clause was found on a SET INITIAL statement or a graphics input statement User Action Remove the duplicate clause DUPLINNOT duplicate line numbers not ANSI Explanation ERROR A program compiled with the ANSISTANDARD qualifier from the DCL command level or called into the VAX BASIC Environment with the OLD command while the ANSI_ STANDARD qualifier is in effect contains two identical lin
514. red an array descriptor but it was not available HP BASIC allocates array descriptors only if the program code requires it User Action None NODIAGFILE unsaved changes no diagnostics file produced Explanation WARNING The program in memory contains changes that have not been saved therefore no diagnostics file will be produced from this compilation User Action SAVE or REPLACE the file Compile Time Error Messages A 61 NOEDIT no change made Explanation WARNING The search string in an EDIT command was not located in the text User Action Enter valid search string NOFILEALL a file specification is not allowed with the REPLACE command Explanation ERROR The REPLACE command does not allow the use of a file specification User Action Use either the SAVE command with a file specification or the REPLACE command without one NOFRAME compiled procedure is currently not active Explanation WARNING A program containing multiple compilation units has been stopped while running in the environment due to a STOP statement or a Ctrl C entered by the user The NOFRAME error indicates that the routine executing when the program stopped is not the last compilation unit in the source file You can examine or modify a variable in immediate mode only if the current routine is the last compilation unit in the source file User Action If you do not intend to debug your program in immediate mode no action is required If yo
515. rent default directory Load the information in the data analysis files into your SCA library with the LOAD command as follows SCA LOAD PG1 PG2 PG3 This command loads your library with the modules contained in the data analysis files PG1 ANA PG2 ANA and PG3 ANA After the SCA library has been prepared enter LSE to begin an SCA session Within this context the integration of LSE and SCA provides commands that can be used only within LSE C 1 2 Compiling From Within LSE To compile a completed HP BASIC program enter the following command at the LSE prompt LSE gt COMPILE To compile an HP BASIC program that contains placeholders and design comments include the following qualifiers to the previous command LSE gt COMPILE ANALYSIS_DATA DESIGN PLACEHOLDERS COMMENTS C 2 Optional Programming Productivity Tools The ANALYSIS_DATA qualifier causes the compiler to generate an analysis data file containing source code analysis information This information is provided to the SCA library The DESIGN qualifier instructs the HP BASIC compiler to recognize placeholders and design comments as valid program elements If the ANALYSIS_DATA qualifier has also been specified the HP BASIC compiler includes information on placeholders and design comments in the analysis data file C 1 3 HP BASIC Support for LSE and SCA Features This section describes information specific to BASIC for programming language placeholders and tokens
516. res an identifier and must be delimited by a HANDLER and an END HANDLER statement Handler names must be valid HP BASIC identifiers and cannot be the same as the identifier for any label PROGRAM name DEF or DEF function SUB FUNCTION or PICTURE subprogram The main advantage of using a detached handler is that it can be referenced by more than one WHEN ERROR USE statement The following example shows a simple detached handler WHEN ERROR USE catcher KILL INPUT DAT END WHEN HANDLER catcher Catch if file does not exist IF ERR 5 THEN CONTINUE END IF END HANDLER The statements within a handler are never executed if an error does not occur or if no protected region exists for the statement that caused the exception Handling Run Time Errors 15 5 15 2 3 When your program generates an error control transfers to the specified handler If the code in an error handler generates a second error control returns to the default HP BASIC error handler and program execution ends usually with the first error only partly processed To avoid the possibility of your error handler causing a second error you should keep handlers as simple as possible and keep operations that might cause errors outside the handler Your handler can include conditional expressions to test the error and branch accordingly as shown in the following example PROGRAM Check_records WHEN ERROR USE Global handler END WHEN HANDLER Global handler SELECT
517. riables No Yes Yes Constants No Local Local copy copy Expressions No Local Local copy copy Nonvirtual No Yes Yes array elements Virtual No Local Local array elements copy copy Nonvirtual No Yes Yes entire arrays Virtual No No No entire arrays Other Parameters RECORD variables No Yes No RFA variables No Yes No Specifies the default parameter passing mechanism 19 1 5 Creating Local Copies If a parameter is an expression function or virtual array element then it is not possible to pass the parameter s address In these cases HP BASIC makes a local copy of the parameter s value and passes this local copy by reference You can force HP BASIC to make a local copy of any parameter by enclosing the parameter in parentheses Forcing HP BASIC to make a local copy is a useful technique because you make it impossible for the subprogram to modify the actual parameter In the following example when variable A is printed in 19 4 Using BASIC in the Common Language Environment 19 1 6 the main program the value is zero because the variable A is not modifiable by the subprogram DECLARE LONG A CALL SUB1 A PRINT A END SUB SUB1 LONG B ae END SUB Output 0 By removing the extra parentheses from A you allow the subprogram to modify the parameter DECLARE LONG A CALL SUB1 A PRINT A END SUB SUB1 LONG B B 3 END SUB Output 3 Passing Arrays In HP BASIC if a subprogram or fu
518. riables used for the graphics input statement is unchanged The pressing of the middle mouse button during a graphics input statement is analogous to typing Ctrl Z at a regular INPUT statement User Action None The program can trap this error in an error handler and attempt the input statement again if so desired VIRARRDIS Virtual array not on disk ERR 43 Explanation The program attempted to reference a virtual array on a nondisk device or the virtual array is not opened as ORGANIZATION VIRTUAL User Action Virtual arrays must be on disk change the file specification in the OPEN statement for this array Open the file with ORGANIZATION VIRTUAL VIRARROPE Virtual array not yet open ERR 45 Explanation The program attempted to reference a virtual array before opening the associated disk file User Action Open the disk file containing the virtual array before referencing the array VIRBUFTOO Virtual buffer too large ERR 42 Explanation The program attempted to access a VIRTUAL file and the buffer size was not 512 bytes User Action Change the I O buffer to be a multiple of 512 bytes B 2 HP BASIC Run Time Errors by Number Table B 1 shows the run time errors by their number and gives an explanation of each error B 30 Run Time Messages Table B 1 BASIC Run Time Errors Error Number Explanation 1 BADDIRDEYV Bad directory for device 2 ILLFILNAM Illegal file name 4 NO_ROOUSE No room for user
519. ring literal or a file specification with the AUDIT qualifier If you specify a string literal BASIC includes it as part of the history entry If you specify a file specification BASIC includes up to the first 64 lines of the specified file When you specify AUDIT BASIC also includes the following information about the CDD Repository record extraction in the history entry e The name of the program module making the extraction e The time and date of the extraction e A note that access was made by way of a BASIC program e A note that the access was an extraction e The username and UIC of the process accessing CDD Repository Remarks e NOAUDIT causes the compiler not to include a history entry in CDD Repository when extracting a CDD Repository definition NO BOUNDS NOJ OVERFLOW NOJINTEGER NO CHECK NO DECIMAL ALL NONE CHECK BOUNDS OVERFLOW default The CHECK qualifier causes the compiler to test for arithmetic overflow and for array references outside array boundaries when the program executes Remarks e In Alpha BASIC specifying CHECK NOBOUNDS causes bounds checking not to be performed on array parameters received by descriptor e CHECK NOBOUNDS should only be used for thoroughly debugged programs and when execution time is critical The program is smaller and runs faster but no error is signaled for an array reference outside the array boundaries The program might get a memory manage
520. rmat Figure 17 7 GFLOAT Floating Point Number Format 63 15 14 3 0 Ss FRAC FRACTION G EXPONENT TION A ZK 5302A GE SFLOAT Floating Point Number Format S_ floating The S_floating floating point number format consists of four contiguous bytes starting on an arbitrary byte boundary as shown in Figure 17 8 Bits are labeled from the right 0 to 31 The form of an S_floating number is sign magnitude with bit 31 the sign bit bits 30 to 23 an excess 127 binary exponent and bits 22 to 0 a normalized 24 bit fraction with the redundant most significant fraction bit not represented unless the exponent is 0 If the exponent is 0 a nonzero fraction represents an unnormalized 23 bit fraction An exponent value of 0 together with a fraction value of 0 and a sign bit of 0 indicates that the S_floating number value is 0 Exponent values from 1 to 254 indicate true binary exponents from 127 to 127 The value of an S_floating number is in the approximate range 1 175 10788 to 3 402 1038 the precision is approximately one part in 27 approximately 7 decimal digits Note that S_floating format provides approximately the same range and precision as F floating format 17 6 Data Representation Figure 17 8 SFLOAT Floating Point Number Format 31 30 23 22 0 S EXPONENT FRACTION A N ZK 9815 GE 17 2 5 TFLOAT Floating Point Number Format T_floating The T floating floating point number format consists of eight contiguous bytes sta
521. rogram includes or appends code from another file the included lines of code are also numbered in sequence by the compiler These line numbers are on the extreme left of a listing file An explanation of the listing file format is in Chapter 2 The PROMPT display at the bottom of the screen shows the debugger prompt DBG gt your input debugger diagnostic messages and program output In the example the debugger commands that have been issued are shown The OUT display in the center of the screen captures the debugger s output in response to the commands that you issue Using the OpenVMS Debugger with BASIC 3 3 The SRC and OUT displays are scrollable so that you can see whatever information scrolls beyond the display window s edge Press KP8 to scroll up and KP2 to scroll down Press KP3 to change the display to be scrolled by default the SRC display is scrolled Scrolling a display does not affect program execution If the debugger cannot locate source lines for the currently executing module it tries to display source lines in the next module down on the call stack for which source lines are available and issues the following message DEBUG I SOURCESCOPE Source lines not available for 0 PC Displaying source in a caller of the current routine Source lines might not be available for the following reasons e The PC is within a system routine or a shareable image routine for which no source code is available e
522. rors while linking object modules it displays messages indicating the cause and severity of the error If any error or fatal error conditions occur errors with severities of E or F the linker does not produce an image file 2 26 Developing HP BASIC Programs The messages produced by the linker are descriptive and you do not usually need additional information to determine the specific error Some common errors that occur during linking are as follows An object module has compilation errors This error occurs when you attempt to link a module that has warnings or errors during compilation You can usually link compiled modules for which the compiler generated messages but you should verify that the modules will actually produce the output you expect The input file has a file type other than OBJ and no file type was specified on the command line If you do not specify a file type the linker assumes the file has a file type of OBJ by default If the file is not an object file and you do not identify it with the appropriate file type the linker signals an error message and does not produce an image file You tried to link a nonexistent module The linker signals an error message if you misspell a module name on the command line or if the compilation contains fatal diagnostics A reference to a symbol name remains unresolved An error occurs when you omit required module or library names from the command line and the linker c
523. roving the performance of your code 14 2 Using Format Strings Format strings determine the way in which items are to be printed in the output file Format strings can be any of the following e String variables e String literals e Named string constants e A combination of the previous strings The PRINT USING statement must contain one or more format strings Each format string is made up of one format field Each format field controls the output of one print item and can contain only certain characters as described throughout the chapter The PRINT USING statement must also contain a list of items you want printed To format print items you must separate them with commas or semicolons Separators between print items do not affect output format as they do with the PRINT statement However if a comma or semicolon follows the last print item HP BASIC does not return the cursor or print head to the beginning of the next line after it prints the last item in the list When HP BASIC encounters an invalid character within the current format field it automatically ends the format field therefore you do not need to delimit format fields The character that terminates the previous field can be either a new format field or a string literal In the following example the first three characters in the format string make up a valid numeric format field The fourth character A is invalid in a numeric format field therefore HP BASIC
524. rrors that can normally be handled or trapped You can specify any one of the following error severity levels BASIC SEVERE ERROR WARNING or INFORMATIONAL OPTION HANDLE BASIC is the default which is in effect if you do not specify an alternative in the OPTION HANDLE statement Only HP BASIC errors that can be trapped transfer control to the current error handler when this option is in effect Refer to Appendix B to determine which BASIC errors cannot be trapped When you specify an error severity level other than BASIC in the OPTION HANDLE statement the following errors will transfer control to the error handler e All BASIC errors that can be trapped of this or lesser severity e All non BASIC errors of this or lesser severity e BASIC errors of this or lesser severity that normally cannot be trapped For example if you specify OPTION HANDLE ERROR you can handle all BASIC and non BASIC errors of ERROR severity both those that can and those that cannot be trapped and all WARNING and INFORMATIONAL errors but no SEVERE errors Handling Run Time Errors 15 11 15 2 5 15 2 5 1 Identifying Errors HP BASIC provides several built in functions that return information about an error You can use these functions inside your error handlers to determine details about the error and conditionally handle these errors These functions include ERR ERL ERN ERT VMSSTATUS RMSSTATUS Note that if an error occurs in your progr
525. rting on an arbitrary byte boundary as shown in Figure 17 9 Bits are labeled from the right 0 to 63 The form of a T_floating number is sign magnitude with bit 63 the sign bit bits 62 to 52 an excess 1023 binary exponent and bits 51 to 0 a normalized 53 bit fraction with the redundant most significant fraction bit not represented unless the exponent is 0 If the exponent is 0 a nonzero fraction represents an unnormalized 52 bit fraction An exponent value of 0 together with a fraction value of 0 and a sign bit of 0 indicates that the T_floating number value is 0 Exponent values from 1 to 2046 indicate true binary exponents from 1023 to 1023 The value of a T_floating number is in the approximate range 2 225 107808 to 1 797 10308 the precision is approximately one part in 25 approximately 15 decimal digits Note that T floating format provides approximately the same range and precision as G_floating format Figure 17 9 TFLOAT Floating Point Number Format 63_ 62 52 51 0 S d EXPONENT FRACTION A N ZK 9816 GE 17 2 6 XFLOAT Floating Point Number Format X_floating The X_floating floating point number format consists of sixteen contiguous bytes starting on an arbitrary byte boundary as shown in Figure 17 10 Bits are labeled from the right 0 to 127 The form of an X_floating number is sign magnitude with bit 127 the sign bit bits 126 to 112 an excess 16383 binary exponent and bits 111 to 0 a normalized 113 bit fraction wit
526. ry use the INCLUDE qualifier and specify the specific modules you want to link For example LINK GARDEN VEGGIES INCLUDE EGGPLANT TOMATO BROCCOLI ONION This example directs the linker to link the object modules EGGPLANT TOMATO BROCCOLI and ONION with the main object module GARDEN Besides program modules an object module library can also contain a symbol table with the names of each global symbol in the library and the name of the module in which they are defined You specify the name of the object module library containing symbol definitions with the LIBRARY qualifier When you use the LIBRARY qualifier during a link operation the linker searches the specified library for all unresolved references found in the included modules during compilation In the following example the linker uses the library RACQUETS to resolve undefined symbols in BADMINTON TENNIS and RACQUETBALL LINK BADMINTON TENNIS RACQUETBALL RACQUETS LIBRARY You can define an object module library such as LNK LIBRARY to be your default library by using the DCL command DEFINE The linker searches default user libraries for unresolved references after it searches modules and libraries specified in the LINK command See the HP OpenVMS DCL Dictionary for more information about the DEFINE command For more information about object module libraries see the HP OpenVMS Linker Utility Manual 2 2 6 Linker Error Messages If the linker detects any er
527. s A ABC BS XYZ PRINT A SPACE 3 B END Output ABC XYZ 11 6 7 TRM Function The TRM function removes trailing blanks and tabs from a string The input string remains unchanged In the following example all trailing blanks that appear in the string expression ABCDE are removed once the TRM function is invoked AS ABCDE BS XYZ firstS AS BS second TRMS A B PRINT firsts PRINT seconds END Output ABCDE XYZ ABCDEXYZ The TRM function is especially useful for extracting the nonblank characters from a fixed length string for example a COMMON or MAP or a parameter passed from a program written in another language 11 6 8 EDIT Function The EDIT function performs one or more string editing functions depending on the value of an argument you supply The input string remains unchanged In the following example stw_rec is a string expression and 32 determines the editing function performed EDITS stu_rec 32 11 16 String Handling Table 11 2 shows the action HP BASIC takes for a given value of the integer expression Table 11 2 EDIT Options Value of Expression Effect 1 Discards each character s parity bit bit 7 Note that you should not use this value for characters in the DEC Multinational character set Discards all spaces and tabs Discards all carriage returns line feeds form feeds deletes escapes and nulls 8 Discards leading spa
528. s PLACENOOB4 placeholders detected no object produced Explanation INFORMATION The program contained one or more placeholders and therefore no object module was created User Action Remove the placeholders from the source code PLACEUNMAT unmatched placeholder delimiter Explanation ERROR A placeholder was syntactically incorrect because the number of opening and closing brackets did not match User Action First make sure that the placeholder does not span multiple source lines Second add or remove brackets until they are appropriately paired PLACEWRDOT invalid placeholder repetition Explanation ERROR A list placeholder was syntactically incorrect Three periods were expected User Action Add trailing periods until there are three periods following the placeholder POIREQONE POINTS output requires at least 1 X Y point Explanation ERROR You do not specify a point in the POINT graphic output statement User Action Specify a minimum of 1 point in the POINT graphic output statement POSGTRTAR starting position greater than target length Explanation ERROR The starting value in the MID statement is greater than the length of the string User Action Correct the value to be less than or equal to the length of the string PRELOGNAM previous logical name assignment replaced Explanation INFORMATION The specified logical name already existed The new equivalence name replaces the old one Use
529. s RMS For a more thorough understanding of file organization and file and record operations see the OpenVMS Record Management Services Reference Manual RMS stores data in physical blocks A block is the smallest number of bytes BASIC transfers in a read or write operation On disk a block is 512 bytes On magnetic tape it is 18 to 8192 bytes RMS stores one or more data records in each block A data record can also be divided into smaller units called fields A data record can be smaller than equal to or larger than a disk block 13 1 Record Formats 13 1 1 The format of a record determines how RMS stores the record in a block You specify the record format in an OPEN statement The following are valid BASIC record formats e Fixed length records e Variable length records e Stream records Fixed Length Records Fixed length records are all the same length RMS stores fixed length records as they appear in the record buffer including any spaces or null characters following the data this process is called padding Processing these records involves less overhead than other record formats however this format can use disk storage space less efficiently than variable length or stream records File Input and Output 13 1 13 1 2 Variable Length Records Variable length records can have different lengths but no record can exceed a maximum size set for the file When the record is written to a file RMS adds a record length h
530. s than or equal to zero User Action Correct the starting value to be greater than or equal to one ILLMODMIK illegal mode mixing Explanation ERROR The program contains string and numeric operands in the same operation User Action Change the expression so that it contains either string or numeric operands but not both ILLMULDEF illegal multiple definition of name lt name gt Explanation ERROR The program uses the same name for e More than one variable e A variable and a MAP e A variable and a COMMON e A MAP and COMMON User Action Use unique names for variables COMMONs and MAPs ILLMULOPT OPTIONAL cannot be specified more than once Explanation ERROR The OPTIONAL clause was specified more than once in the EXTERNAL statement for a single SUB or FUNCTION This is not allowed because OPTIONAL implies that all parameters following it are optional User Action Fix the EXTERNAL statement so that it has at most one OPTIONAL clause per SUB or FUNCTION ILLNESDEF illegally nested DEFs Explanation ERROR The program contains a DEF function block within another DEF function block User Action Remove the inner DEF block A DEF cannot contain another DEF A 40 Compile Time Error Messages ILLOPEARG illegal operation for argument Explanation ERROR The program performs an operation that is inconsistent with the data type of the arguments for example an arithmetic operation on variables of the RFA dat
531. s then the value of B HP BASIC prints the three spaces because they are treated as a string literal in the format string Notice that when HP BASIC reuses a format string it begins on a new line 14 3 Printing Numbers With the PRINT USING statement you can specify e The number of digits to print thus rounding the number to a given place e The decimal point location thus vertically aligning numbers at the decimal point e Special symbols including trailing minus signs asterisk filled number fields floating currency symbols embedded commas and E notation e Debits and credits Formatting Output with the PRINT USING Statement 14 3 14 3 1 e Leading zeros or leading spaces e Blank if zero fields e A special character that is to be printed as a literal Unlike the PRINT statement PRINT USING does not automatically print a space before and after a number Unless you reserve enough digit positions to contain the integer portion of the number and a minus sign if necessary HP BASIC prints a percent sign to signal this condition and displays the number in PRINT format Specifying the Number of Digits You reserve places for digits by including a number sign for each digit position If you print negative numbers you must also reserve a place for the minus sign PRINT USING 123 Three places reserved PRINT USING 12345 Five places reserved PRINT USING 678 Four places reserved END Output 1
532. s a routine that provides a simpler more easily used interface to a system service If you call a routine in the SMG facility you must include the definition file SMGDEF All system services however require that you include SSDEF to check status Many other system services require other symbol definitions as well To determine whether or not you need to include other symbolic definitions for the system service you want to reference see the documentation for that service If the documentation states that values are defined in the specified macro you must include those symbolic definitions in your program BASIC provides a text library that contains symbolic definitions that can be accessed using the INCLUDE directive In the following example the definition file SMGDEF is included from the text library SYS LIBRARY BASIC STARLET TLB SINCLUDE SMGDEF FROM SLIBRARY SYSSLIBRARY BASICSSTARLET TLB For more information about including text libraries see Chapter 16 19 18 Using BASIC in the Common Language Environment 19 4 5 Condition Values Many system routines return a condition value that indicates success or failure If a condition value is returned you should check this value after you call a system routine and control returns to your program Condition values indicating success always appear first in the list of condition values for a particular routine and success codes always have odd values A success code that is common
533. s and by a minus sign for negative numbers The numeric string is always followed by a space For example PRINT NUM 7465097802134 PRINT NUM 50 END Output 74651E 13 50 The NUM1 function translates a number into a string of numeric characters NUM1 does not return leading or trailing spaces or E format The following example shows the use of the NUM1 function PRINT NUM1 PI PRINT NUM1 97 5 30456 23 30385 1 PRINT NUM1 1E 38 END Output 3 14159 2999870 00000000000000000000000000000000000001 10 8 Functions 10 1 3 3 NUM1 returns up to 6 digits of accuracy for SINGLE and SFLOAT real numbers up to 16 digits of accuracy for DOUBLE numbers up to 10 digits of accuracy for LONG integers and up to 19 digits of accuracy for QUAD integers NUM1 returns up to 15 digits of accuracy for GFLOAT and TFLOAT numbers and up to 33 digits of accuracy for XFLOAT numbers The following example shows the difference between NUM and NUM1 AS NUMS 1000000 BS NUM1 1000000 PRINT LEN AS AS PRINT LEN BS BS END Output 8 1E 07 7 1000000 Note that A has a leading and trailing space VAL and VAL Functions The VAL function returns the integer value of a numeric string This numeric string expression must be the string representation of an integer It can contain the ASCII characters 0 to 9 a plus sign or a minus sign The VAL function returns the floating p
534. s brought into memory the FOR NEXT loop deblocks the data into 128 byte logical records At each iteration of the FOR NEXT loop the REMAP statement uses the loop variable to mask off 128 byte sections of the block For more information about the MAP DYNAMIC and REMAP statements see Chapter 7 and the HP BASIC for OpenVMS Reference Manual MOVE Statement The MOVE statement defines data fields and moves them to and from the record buffer created by HP BASIC For example MOVE FROM 9 A Cost Name 30 ID_num This statement moves a record with four data fields from the record buffer to the variables in the list as follows e A string field A with a default length of 16 characters e A number field Cost of the default data type e A second 30 character string field Name e An integer field ID_num Valid variables in the MOVE list are e Scalar variables e Arrays e Array elements e FILL items Because BASIC dynamically assigns space for string variables the default string length during a MOVE TO operation is the length of the string The default for MOVE FROM is 16 characters An entire array specified in a MOVE statement must include the array name followed by n 1 commas where n is the number of dimensions in the array Note that these commas must be enclosed in parentheses You specify a single array element by naming the array and the subscripts of that element The following statement moves three arrays from the
535. s of the general formula e To replace the first n characters of A with B use C B SEG A n 1 LEN AS e To replace all but the first n characters of A with B use C SEGS A 1 n B e To replace all but the last n characters of A with B use C B SEGS A LEN A n 1 LEN AS e To replace the last n characters of A with B use C SEGS A 1 LEN A n BS e To insert B in A after the nth character in A use C SEGS A 1 n B SEGS A n 1 LEN A 11 6 4 MID Function The MID function extracts a specified substring beginning at a specified character position and ending at a specified length If you specify a starting character position that is less than 1 HP BASIC automatically assumes a starting character position of 1 In the following example the MID function uses the input string ABCD and extracts a segment consisting of 3 characters Because HP BASIC automatically assumes a starting character position of 1 when the specified starting character position is less than 1 the string that is extracted begins with the first character of the input string DECLARE STRING old string new string old string ABCD new string MIDS old string 0 3 PRINT new_string 11 14 String Handling Output ABC Keep these considerations in mind when you use MID e Ifthe position of the segment s first character is greater than the input string MID returns a null string e Ifthe leng
536. s required because the GROUP is an array the elliptical reference to this component must include the desired array element in this case the second element of the Children array RECORD templates RECORD Family GROUP Extended_family STRING Grandfather 1 STRING Grandmother 1 30 30 Two element fixed length string arrays for the names of maternal and paternal grandparents GROUP Nuclear_family STRING Father 0 STRING Mother 0 Fixed length strings for the names 3 3 of parents Creating and Using Data Structures 8 9 GROUP Children 10 An 1ll element array for the names and gender of children STRING Kid 10 STRING Gender 1 END GROUP Children END GROUP Nuclear family END GROUP Extended family END RECORD Declarations DECLARE Family My family Program logic starts here My_family Extended_family Nuclear_family Children 1 Kid Johnny PRINT My family Children 1 Kid END Output Johnny RECORD Templates RECORD Test INTEGER Test_integers 2 3 element array of integers GROUP Group_1 Single GROUP containing REAL My number a real number and STRING Group_1_ string a 16 character default string END GROUP GROUP Group _2 5 A 6 element GROUP each element containing INTEGER My number an integer and DECIMAL Group 2 decimal a DECIMAL number END GROUP END RECORD Declarations DECLARE Test Array of test 10 Create an 1l element array of type Test DECLARE Test
537. s shown in the last example in this section in which the value of a specified variable is displayed However at tracepoints unlike breakpoints the program continues executing and the debugger prompt is not displayed For example DBG gt SET TRACE COUNTER DBG gt GO trace at TEST COUNTER 34 SUB COUNTER LONG X Y When using the SET TRACE command you specify address expressions qualifiers and optional clauses exactly as with the SET BREAK command The LINE qualifier instructs the SET TRACE command to trace every line and is a convenient means of checking the execution path By default lines are traced within all called routines as well as the currently executing routine If you do not want to trace system routines or routines in shareable images use the NOSYSTEM or NOSHARE qualifiers For example DBG gt SET TRACE LINE NOSYSTEM NOSHARE Using the OpenVMS Debugger with BASIC 3 9 The SILENT qualifier suppresses the trace message and source code display This is useful when you want to use the SET TRACE command to execute a debugger command at the tracepoint For example DBG gt SET TRACE SILENT LINE 83 DO EXAMINE STATUS DBG gt GO SCREEN IO CLEAR STATUS OFF 3 4 5 Monitoring Changes in Variables The SET WATCH command lets you set watchpoints that will be monitored continuously as your program executes If the program modifies the value of a watched variable the debugger suspends execution and displays
538. s the RESUME statement unless that line or target is inside a DEF function a WHEN ERROR protected region or a handler In general RESUME without a target transfers control to the beginning of the program block where the error occurred e Ifyou resume execution at a multistatement line execution begins at the first statement after the line number or label not necessarily at the statement that generated the error e Ifan entire loop block is associated with a single line number or label and an error occurs within the loop RESUME with no target transfers control to the statement immediately after the FOR WHILE or UNTIL statement not to the line number or label For more information about the RESUME statement see the HP BASIC for OpenVMS Reference Manual Using both ON ERROR statements and WHEN ERROR constructs in the same program is not recommended However when this is the case the order of handler priorities is as follows 1 Control passes to the handler associated with the innermost WHEN ERROR block 2 If protected regions are nested the pending error is handled by the handler associated with the next outer WHEN ERROR block 3 When no outer protected regions can handle the error and if an ON ERROR statement is in effect control transfers to the target of the next outer ON ERROR statement if one is present 4 If no outer handler is available or can handle the error the error is passed to HP BASIC default error han
539. s to perform an invalid network operation or the network software failed during a network operation User Action Take action based on the associated error messages NODNAMERR Node name error ERR 175 Explanation A file specification s node name contains a syntax error User Action Supply a valid node name NOTBASIC Not a BASIC error ERR 194 Explanation The error is not a HP BASIC error and is not mapped to an alternative HP BASIC error message User Action Use RMSSTATUS or VMSSTATUS to access the text of the error message NOTENDFIL Not at end of file HRR 149 Explanation The program attempted a PUT operation 1 on a sequential or relative file before the last record or 2 without opening the file for WRITE access User Action OPEN a sequential or relative file with ACCESS APPEND or OPEN the file with ACCESS WRITE NOTENOAVA Not enough available memory ERR 111 Explanation The program has exhausted its virtual space limits User Action Raise the user PGFLQUOTA limit NOTENODAT Not enough data in record ERR 59 Explanation An INPUT statement did not find enough data in one line to satisfy all the specified variables User Action Supply enough data in the record or reduce the number of specified variables Run Time Messages B 21 NOTIMP Not implemented ERR 250 Explanation The program attempted to use a feature that does not exist in this version of HP BASIC for example TIME 4 User Ac
540. se or specify that a list of commands be executed at the breakpoint with a DO clause on the debugger command For example the next command sets a breakpoint on the label LOOP3 The DO EXAMINE TEMP clause causes the value of the variable TEMP to be displayed whenever the breakpoint is triggered DBG gt SET BREAK LOOP3 DO EXAMINE TEMP DBG gt GO break at COUNTER LOOP3 37 LOOP3 FOR I 1 TO 10 COUNTER TEMP 284 19 DBG gt To display the currently active breakpoints enter the SHOW BREAK command DBG gt SHOW BREAK breakpoint at SCREEN IO SLINE 58 breakpoint at COUNTER LOOP3 do EXAMINE TEMP DBG gt 3 8 Using the OpenVMS Debugger with BASIC To cancel a breakpoint enter the CANCEL BREAK command specifying the program location exactly as you did when setting the breakpoint The CANCEL BREAK ALL command cancels all breakpoints 3 4 4 Tracing Program Execution The SET TRACE command lets you select tracepoints which are locations for tracing the execution of your program without stopping its execution After setting a tracepoint you can start execution with the GO command and then monitor the PC s path checking for unexpected behavior By setting a tracepoint on a routine you can also monitor the number of times the routine is called As with breakpoints every time a tracepoint is reached the debugger issues a message and displays the source line It can also display other information that you have specified a
541. sed by descriptor Specify the BY DESC passing mechanism either in the EXTERNAL declaration or the subprogram invocation REMNOTALL REM statement not allowed in programs without line numbers Explanation ERROR A REM statement has been found in a program without line numbers User Action Remove the REM statement REPLACE assuming lt operator s gt replaced by lt operator gt Explanation ERROR The program contains a syntax error HP BASIC found incorrect or multiple operators where another single operator makes more sense for example 10 A B Compilation continues so that other errors can be detected The actual program line remains unchanged and no object file is produced User Action Examine the line carefully to discover the error Change the program line to correct the syntax error REQNUMEXP lt item gt requires a numeric expression Explanation ERROR The program contains a string expression in a context requiring a numeric expression User Action Supply a numeric expression Compile Time Error Messages A 75 REQSTREXP lt item gt requires string expression Explanation ERROR The program contains a numeric expression in a context requiring a string expression for example the file specification in an OPEN statement or the default file specification in a DEFAULTNAME clause User Action Supply a string expression RESABOCON RESEQUENCE aborted due to conditional compilation Explanation ERROR
542. sing the OpenVMS Debugger with BASIC 3 15 BASIC LIST DEBUG SAMPLE LINK DEBUG SAMPLE RUN SAMPLE VAX DEBUG Version n n SDEBUG I INITIAL language is BASIC module set to SAMPLESMAIN DBG gt STEP 2 NUMBER SQUARE SQUARE ROOT stepped to SAMPLESMAIN line 7 7 FOR Number 10 TO 1 STEP DBG gt STEP 4 10 100 3 16228 stepped to SAMPLESMAIN SLINE 7 T FOR Number 10 TO 1 STEP 1 DBG gt EXAMINE Number 10 SAMPLE MAIN NUMBER 10 DBG gt STEP 4 10 100 3 16228 stepped to SAMPLESMAIN SLINE 7 Ts FOR Number 10 TO 1 STEP 1 DBG gt EXAMINE Number SAMPLE MAIN NUMBER 10 DBG gt DEPOSIT Number 9 DBG gt STEP 4 9 81 3 stepped to SAMPLESMAIN SLINE 7 Ls FOR Number 10 TO 1 STEP 1 DBG gt EXAMINE Number SAMPLESMAIN NUMBER 9 DBG gt STEP 9 81 3 stepped to SAMPLESMAIN LINE 8 8 PRINT Number Number 2 SQR Number DBG gt STEP stepped to SAMPLESMAIN SLINE 9 9 Number Number 1 DBG gt EXIT The following explains the terminal dialogue in the above example Compile SAMPLE BAS with the LIST and DEBUG qualifiers The listing file can be useful while you are in the debugging session Link SAMPLE BAS with the DEBUG qualifier The debugger identifies itself and displays the debugger prompt after you invoke the debugger with the RUN command Step through 2 executable statements to the FOR statement oo 00O 86 The headers print successfully and the program reaches
543. source text from a file into the source program The INCLUDE directive also lets you access record definitions in CDD Repository as well as access source text from a text library The line on which a INCLUDE directive resides can be continued but cannot contain any other directives or statements If you are including a source text file you must supply a file specification If you do not provide a file type BASIC uses the default type BAS For example SINCLUDE KEN BAS If you are including a CDD Repository definition you must supply a valid CDD Plus path specification to extract a RECORD definition from CDD Repository For example SINCLUDE FROM CDD CDDSTOP EMPLOYEE See the CDD Repository CDO Reference Manual for more information about CDD Repository If you are including source text from a text library you must supply the name of the text module you wish to include as well as the name of the library where the module resides If you do not specify a library name BASIC uses the default library BASIC LIBRARY Moreover if you do not specify a directory name or file type BASIC uses the default device and the file type TLB If the BASIC LIBRARY logical name is undefined SYS LIBRARY BASIC STARLET TLB is used The default file specification is BASIC TLB In the following example when BASIC encounters the INCLUDE directive the compiler searches through the library SYS LIBRARY BASIC_LIB TLB for the specified module DMB_TEST
544. spaces and truncates longer strings on the right to fit the field A left justified field contains a single quotation mark followed by a series of Ls PRINT USING LLLLLL ABCDE PRINT USING LLLL ABC PRINT USING LLLLL 12345678 END Output ABCDE ABC 123456 Right Justified Format BASIC prints strings in a right justified field starting with the rightmost character BASIC pads the left side of shorter strings with spaces If a string is longer than the field BASIC left justifies and truncates the right side of the string A right justified field contains a single quotation mark followed by a series of Rs DECLARE STRING CONSTANT right justify RRRRR PRINT USING right justify ABCD PRINT USING right justify A PRINT USING right justify STUVWXYZ END Output ABCD A STUVWX 14 14 Formatting Output with the PRINT USING Statement 14 4 3 14 4 4 Centered Fields BASIC prints strings in a centered field by aligning the center of the string with the center of the field If BASIC cannot exactly center the string as is the case for a 2 character string in a 5 character field for example BASIC prints the string one character off center to the left A centered field contains a single quotation mark followed by a series of Cs DECLARE STRING CONSTANT center CCCC PRINT USING center A PRINT USING center AB PRINT USING center ABC PRINT USING center ABCD PRI
545. stant HT horizontal tab to separate fields in the employee record MAP FIELDS STRING full_name 10 amp address 10 amp city state 10 amp zip 10 LINPUT NAME full name LINPUT ADDRESS address LINPUT CITY AND STATE city state LINPUT ZIP CODE zip EMPLOYEE RECORDS full name HT address HT amp city state HT zip PRINT EMPLOYEE RECORD END Output NAME JOE SMITH ADDRESS 66 GRANT AVENUE CITY AND STATE NEW YORK NY ZIP 01001 JOE SMITH 66 GRANT A NEW YORK N 01001 11 4 Using String Virtual Arrays Virtual arrays are stored on disk You create a virtual array by opening a disk file and then using the DIM statement to dimension the array on the open channel This section describes only string virtual arrays See Chapter 13 for more information about virtual arrays Elements of string virtual arrays behave much like dynamic strings with the following exceptions e When you create the virtual string array you specify a maximum length for the array s elements The length of an array element can never exceed this maximum If you do not supply a length the default is 16 characters e A string virtual array element cannot contain trailing nulls 11 4 String Handling When you assign a value to a string virtual array element HP BASIC pads the value with nulls if necessary to fit the length of the virtual array element however when you retrieve the virtual array element H
546. statement control passes back to the outer procedure s handler The error is assumed to occur on the statement where the call or invocation occurs Determining Where the Error Occurred ERN You use the ERN function to return the name of the program unit in which the error was detected ERN returns the name of a main program SUB FUNCTION or PICTURE subprogram or DEF function If the PROGRAM statement is used with a user supplied identifier the ERN value is the specified identifier for the main program The results of ERN are undefined until the program generates an error In the following example control passes to the main program for error handling if the error occurs in the module SUBARC HANDLER locat ern IF ERNS SUBARC THEN PRINT ERROR IS ERR PRINT RETURNING TO MAIN PROGRAM FOR ERROR HANDLING EXIT HANDLER ELSE PRINT PROGRAM MODULE GENERATING ERROR IS ERNS END IF END HANDLER Note that ERN is invalid when an error occurs in a subprogram compiled with the NOSETUP qualifier Determining the Error Message Text ERT You use the ERT function to access the message text associated with a specified error number Use of the ERT function is not limited to the scope of the error handler you can access ERT at any time The following detached handler tests whether the error occurred in a DEF module named TSLFE and if so prints the text of the signaled error and resumes execution HANDLER catch it IF ERNS
547. structure Once a data structure or RECORD has been named and defined you can use that RECORD name anywhere that you can use a BASIC data type keyword You build the data structure using e Variables of any valid BASIC data type e RECORD variables of previously defined RECORD data types e Any combination of the two The following example creates a RECORD called Employee Employee is a data structure that contains one LONG integer one 10 character string one 20 character string and one 11 character string Creating and Using Data Structures 8 1 RECORD Employee LONG Emp number STRING First name 10 STRING Last name 20 STRING Soc sec number 11 END RECORD Empolyee To create instances of this data structure you use declarative statements In the following example the first DECLARE statement creates a variable called Emp_rec of data type Employee The second DECLARE statement creates a one dimensional array called Emp_array that contains 1001 instances of the Employee data type DECLARE Employee Emp rec DECLARE Employee Emp array 1000 Any reference to a RECORD component must contain the name of the RECORD instance that is the name of the declared variable and the name of the elementary RECORD component you are accessing separated by two colons For example the following program assigns values to an instance of the Employee RECORD template Record Template RECORD Employee LONG Emp number STRING First name
548. t Because the length of the returned string does not change it is either padded with spaces or truncated To pass an array to a FORTRAN subprogram you must specify BY REF Note that FORTRAN arrays are one based while HP BASIC arrays are zero based by default For example in FORTRAN the array Two_D 5 3 represents a 5 by 3 matrix while in HP BASIC the array Two_d 5 3 represents a 6 by 4 matrix You can adjust your array bounds in HP BASIC by using the keyword TO when defining the array bounds For more information about array bounds see Chapter 6 When passing two dimensional arrays as parameters keep in mind that FORTRAN addresses array elements in column major order while BASIC refers to array elements in row major order That is FORTRAN arrays are of the form Fortran_array column row while HP BASIC array elements are addressed as Basic_array row column The FORTRAN array Grid x y is therefore referred to as GRID y x in HP BASIC You should reverse references to array elements when passing arrays between HP BASIC and FORTRAN program modules You can do this in one of two ways e Reverse array bounds in parameter lists e Switch row and column variables within loops in your program module Example 19 1 shows a HP BASIC program that passes a two dimensional array to a FORTRAN subprogram The FORTRAN subprogram is shown in Example 19 2 Using BASIC in the Common Language Environment 19 9 Example 19 1 BASIC Main Program P
549. t The MAT INPUT statement assigns values from your terminal to array elements The MAT INPUT statement reads data from a terminal format file and writes it to an array The optional subscripts in a MAT INPUT statement define either the dimensions of the array being created implicitly or the new dimensions of an existing array If you are implicitly creating the array the value of a subscript cannot exceed 10 6 14 Arrays The MAT INPUT statement requests data from your terminal as does the INPUT statement it prints a question mark prompt that you can disable with the SET NO PROMPT statement and then enable with the SET PROMPT statement However you cannot include a string prompt with the MAT INPUT statement When you enter a series of values separated by commas BASIC enters the values you supply into successive array elements by row starting with element 1 1 and filling row 1 before starting row 2 If you provide fewer data items than there are elements the remaining elements are unchanged If you provide more items than there are elements BASIC ignores the excess The MAT INPUT statement takes values from an open file and assigns them to the matrix elements by rows starting with element 1 1 It fills the elements in row 1 before starting row 2 The file can have one or more values in each record however multiple values must be separated with commas In the following example the open file on channel 3 contains the fo
550. t Because test is five characters long the RSET statement pads XYZ with two spaces when assigning the value The PRINT statement shows that test includes these two spaces LET test ABCDE RSET test XYZ PRINT test nrn END Output XYZ If the string expression s value is longer than the string variable RSET right justifies the string expression and truncates characters on the left to fit the string variable as shown in the following example String Handling 11 7 11 5 4 LET test ABCDE RSET test 987654321 PRINT test END Output 54321 The LET statement creates a 5 character string variable test The RSET statement assigns 54321 to test RSET which does not change the variable s length truncates 9876 from the left side of the string expression Note that when using LSET and RSET padding can become part of the data LET AS 12345 LSET A ABC LET BS 12345678 RSET BS A PRINT nmn B wri Output ABC MID Assignment Statement You can replace a portion of a string with another string using the MID assignment statement You specify a starting character position that indicates where to begin the substitution If you specify a starting character position that is less than 1 HP BASIC assumes a starting character position of 1 In addition you can optionally specify the number of characters to substitute from the source string expression If yo
551. t block gt without matching lt item gt Explanation ERROR The program contains an END SELECT END DEF END FUNCTION FUNCTIONEND SUBEND END SUB or END IF without a matching SELECT DEF SUB FUNCTION or IF User Action Supply a SELECT DEF FUNCTION SUB or IF to match the END lt block gt statement or remove the erroneous END statement FOUND found lt item gt when expecting lt item gt Explanation ERROR The program contains a syntax error HP BASIC displays the item where the error was detected then displays one or more items that make more sense in that context The compilation continues so that other errors can be detected The actual program line remains unchanged and no object file is produced User Action Examine the line carefully to discover the error Change the program line to correct the syntax error Compile Time Error Messages A 33 FOUNXTWIT found NEXT without matching WHILE or UNTIL Explanation ERROR The program contains a NEXT statement without a corresponding WHILE or UNTIL statement User Action Supply a WHILE or UNTIL statement or remove the erroneous NEXT statement FOUWITMAT found NEXT without matching FOR Explanation ERROR The program contains a NEXT lt control variable gt statement without a matching FOR lt control variable gt statement User Action Supply a FOR statement or remove the erroneous NEXT statement FUNINVNOT function invocation not allowed in assignment
552. t it is greater than zero STRTOOLON String too long ERR 227 Explanation The program attempts to create a string longer than 65 535 bytes User Action Reduce the length of the string SUBOUTRAN Subscript out of range ERR 55 Explanation The program attempts to reference an array element outside of the array s dimensioned bounds User Action Check program logic to make sure that all array references are to elements within the array boundaries TAPBOTDET Tape BOT detected ERR 129 Explanation The program attempts a rewind or backspace operation on a magnetic tape that is already at the beginning of the file User Action Trap the error or check program logic do not rewind or backspace if the magnetic tape is at the beginning of the file Run Time Messages B 27 TAPNOTANS Tape not ANSI labeled ERR 146 Explanation The program attempts to access a file structured magnetic tape that does not have an ANSI label User Action Determine the magnetic tape s format by mounting it with the FOREIGN qualifier and using the DCL DUMP command You can then access it as a non file structured magnetic tape TAPRECNOT Tape records not ANSI ERR 128 Explanation The records in the magtape you accessed are neither ANSI D nor ANSI F format User Action Determine the magtape s format by mounting it with the FOREIGN qualifier and using the DCL DUMP command TERFORFIL Terminal format file required ERR 164 Expla
553. t lib name gt Explanation ERROR The module name you specified in a INCLUDE directive was not found in the text library you specified User Action Place the module name in the specified text library MULCHRARR multiple character array name not ANSI Explanation INFORMATION A program compiled with the ANSI_ STANDARD qualifier contains an array whose name contains more than one character User Action Reduce the length of the name to a single character MULCHRDEF multiple character DEF name not ANSI Explanation INFORMATION A program compiled with the ANSI_ STANDARD qualifier contains a DEF whose name contains more than one character User Action Reduce the length of the name to a single character MULDEFLEX multiple definition of lexical identifier is illegal Explanation ERROR A lexical constant is named in more than one LET directive User Action Declare the lexical constant only once with LET MULHANSPE multiple handlers specified for WHEN block Explanation ERROR A WHEN block specifies both an attached and detached error handler User Action Change the WHEN block to specify either an attached or detached error handler MULMAIPROG multiple main program units are illegal Explanation ERROR More than one main program unit has been detected in a single source file User Action Modify your source file so that all HP BASIC statements are contained within a single main program or within a sub
554. t on Format Number sign Reserves a place for one digit Decimal point period Determines decimal point location and reserves a place for the radix point Comma Prints a comma before every third digit to the left of the decimal point and reserves a place for one digit or digit separator Two asterisks Print leading asterisks before the first digit and reserve places for two digits continued on next page 14 6 Formatting Output with the PRINT USING Statement 14 3 3 1 Table 14 1 Cont Format Characters for Numeric Fields Character Effect on Format Two dollar signs Four carets Minus sign Zero in angle brackets lt 0 gt Percent sign in angle brackets lt gt CD in angle brackets lt CD gt Underscore _ Print a currency symbol before the first digit They also reserve places for the currency symbol and one digit By default the currency symbol is a dollar sign To change the currency symbol see Section 14 3 3 3 Print a number in E exponential format and reserve four places for E notation Prints a trailing minus sign for negative numbers Printing a negative number in an asterisk fill or a currency field requires that the field also have a trailing minus sign or credit debit character Prints leading zeros instead of leading spaces Prints all spaces in the field if the value of the print item when rounded to fit the numeric field is zero
555. t redimension virtual arrays with an executable DIM statement See Chapter 6 for more information about virtual arrays Locating Records The FIND statement locates a specified record and makes it the current record Using the FIND statement to locate records can be faster than using a GET statement because the FIND statement does not transfer any data to the record buffer therefore it executes faster than a GET statement However if you are interested in the contents of a record you must retrieve it with a GET operation The FIND statement sets the current record pointer to the record just found making it the target for a GET UPDATE or DELETE statement Note that you must have write access to a record before issuing a PUT UPDATE or DELETE operation A sequential FIND operation searches records in the following order e Sequential files from beginning to end e Relative files in ascending relative record or cell number order 13 14 File Input and Output e Indexed files in ascending or descending order based on the current key of reference and the key s collating sequence For sequential fixed length and relative files you can find a particular record by specifying a RECORD clause This is called a random access FIND You can also perform a random access FIND for indexed files by specifying a key of reference a relational test and a key value In the following example the first FIND statement finds the first record whose
556. t that mailbox as a normal record file You must have TMPMBX or PRMMBxX privilege to create mailboxes Mailboxes are created and deleted by system services For more information about using system services in HP BASIC programs see Chapter 19 Use the EXTERNAL statement to define the SYS CREMBX system service that creates the mailbox In HP BASIC programs you create mailboxes by invoking SYS CREMBxX as a function passing either a channel argument and a string literal or a logical name for the mailbox For example EXTERNAL INTEGER FUNCTION SYSSCREMBX SYSSSTATUS SYS CREMBX CHAN CONFIRMATION MBX If you supply a logical name for the mailbox be sure that it is in uppercase letters Once you create the mailbox you can use it as a logical file name The following two examples when executed on two separate processes allow you to send and receive data from one process to another Advanced File Input and Output 18 13 Example 1 DECLARE STRING passenger name Confirm msg OPEN CONFIRMATION MBX AS FILE 1 INPUT WHAT IS THE PASSENGER NAME passenger name PRINT 1 passenger name LINPUT 1 confirm msg PRINT confirm msg END Z Example 2 MAP res STRING passenger name 32 DECLARE WORD mbx chan LONG sys status EXTERNAL LONG FUNCTION sys crembx LONG WORD LONG LONG amp LONG LONG STRING WHEN ERROR USE err trap sys status sysScrembx mbx chan CONFIRMATION MBX OPEN CONFIRMATION MBX FO
557. ta type If you supply an integer argument EXP converts it to the default floating point data type and returns a value of that type RND Function The RND function returns a number greater than or equal to zero and less than 1 The RND function always returns a floating point number of the default floating point data type The RND function generates seemingly unrelated numbers However given the same starting conditions a computer always gives the same results Each time you execute a program with the RND function you receive the same results PRINT RND RND RND RND END Output 1 76308 179978 902878 88984 Output 2 76308 179978 902878 88984 With the RANDOMIZE statement you can change the RND function s starting condition and generate random numbers To do this place a RANDOMIZE statement before the line invoking the RND function Note that the RANDOMIZE statement should be used only once in a program With the RANDOMIZE statement each invocation of RND returns a new and unpredictable number RANDOMIZE PRINT RND RND RND RND END Functions 10 5 10 1 2 10 1 2 1 Output 1 403732 34971 15302 92462 Output 2 404165 272398 261667 10209 The RND function can generate a series of random numbers over any open range To produce random numbers in the open range A to B use the following formula B A RND A The following program produces 10 numbers in the open range 4 to 6 FOR I 1 TO 10 PRINT 6
558. tatement following the end of the control structure You can use ITERATE to explicitly reexecute a FOR NEXT WHILE NEXT or UNTIL NEXT loop EXIT and ITERATE statements can appear only within the code blocks you want to leave or reexecute Executing the ITERATE statement is equivalent to transferring control to the loop s NEXT statement The termination test is still performed when the NEXT statement transfers control to the top of the loop In addition transferring control to the NEXT statement means that a FOR loop s control variable is incremented by the STEP value Supplying a label for every loop lets you state explicitly which loop to leave or reexecute If you do not supply a label for the ITERATE statement HP BASIC reexecutes the innermost active loop For example if an ITERATE statement that does not specify a label is executed in the innermost of three nested loops only the innermost loop is reexecuted In contrast labeling each loop and supplying a label argument to the ITERATE statement lets you reexecute any of the loops A label name also helps document your code Because you must use a label with EXIT and it is sometimes necessary to use a label with ITERATE you should always label the structures you want to control with these statements The following example shows the use of both the EXIT and ITERATE statements This program explicitly exits the loop if you type a carriage return in response to the prompt If
559. tatement it assumes that first is a new variable that is not declared in the main program If you try to run this example HP BASIC signals the error Explicit declaration of first required If you do not specify the OPTION TYPE EXPLICIT statement HP BASIC assumes that first is a new variable and initializes it to zero OPTION TYPE EXPLICIT DECLARE INTEGER A B DEF fn_sum INTEGER first INTEGER second first second A 50 B 25 PRINT fn sum A B PRINT first END 10 24 Functions 11 String Handling This chapter defines dynamic and fixed length strings and string virtual arrays explains which you should choose for your application and shows you how to use them 11 1 Overview of Strings A string is a sequence of ASCII characters BASIC allows you to use the following types of strings e Dynamic strings e Fixed length strings e String virtual arrays Dynamic strings are strings whose length can change during program execution The length of a dynamic string variable can change or not depending on the statement used to modify it Fixed length strings are strings whose length never changes In other words their length remains static String constants are always fixed length String variables can be either fixed length or dynamic A string variable is fixed length if it is named in a COMMON MAP or RECORD statement If a string variable is not part of a map or common block RECORD or virtual array it is
560. tatement in an outer nesting level as an implicit END IF for all unterminated IF statements at that point For example in the following construction the third ELSE terminates both inner IFs IF expression THEN IF expression THEN statement list ELSE IF expression THEN statement list ELSE statement list ELSE In the following example the first IF THEN ELSE statement is ended by END IF and works as expected Because the second IF THEN ELSE statement is not terminated by END IF the HP BASIC compiler assumes that the last PRINT statement in the program is part of the second ELSE clause 10 DECLARE INTEGER light bulb DECLARE INTEGER circuit switch DECLARE INTEGER CONSTANT Opened 0 DECLARE INTEGER CONSTANT Closed 1 PRINT Please enter zero or one corresponding to the circuit PRINT switch being open or closed INPUT On_off val IF On off val Opened THEN PRINT The light bulb is off ELSE PRINT The light bulb is on END IF IF On off val Closed THEN PRINT The light bulb is on ELSE PRINT The light bulb is off PRINT That s all for now 20 END When you run the program the first IF THEN ELSE statement will always execute correctly Program Control 9 11 The final PRINT statement will execute only when the value of On_off_val is 1 that is closed because the compiler considers this PRINT statement to be part of the second ELSE clause Output 1 Please enter zero or one correspo
561. tatement matches that of the actual constant VALUEREQ PRINT USING requires a value Explanation ERROR A PRINT USING statement must have at least one expression or value User Action Supply an expression or value at the end of the PRINT USING statement VARCONREQ variable or constant required Explanation ERROR The program contains an executable DIM statement that contains an expression in the bounds list User Action Remove the expression from the bounds list Executable DIM statements can have only constants or variables simple or subscripted as bounds Compile Time Error Messages A 89 VARNOALGN Variable lt name gt within COMMON or MAP is not naturally aligned Explanation WARNING lIdentifies a variable within a COMMON or MAP that was found not to be naturally aligned This error is only reported when the WARNING ALIGNMENT qualifier is in effect User Action Modify COMMON or MAP so that all variables are naturally aligned VERJUSMUS vertical justification must be TOP CAP HALF BASE BOTTOM or NORMAL Explanation ERROR You specified an invalid value for the vertical component of the SET TEXT JUSTIFY statement User Action Specify one of the values listed in the message VIRARROVF virtual array space exceeded at array lt name gt Explanation ERROR The storage for virtual arrays on a single channel exceeds 2 147 483 647 bytes User Action If there is only
562. te that the last three parameters can be optional LONG FUNCTION LIBSLOOKUP_KEY STRING LONG OPTIONAL LONG STRING INTEGER For more information about using the EXTERNAL statement see the HP BASIC for OpenVMS Reference Manual Calling the Routine Once you have declared an external routine you can invoke it To invoke a procedure you use the CALL statement To invoke a function you use the function name in an expression You must specify the name of the routine being invoked and all parameters required for that routine Make sure the data types and passing mechanisms for the actual parameters you are passing match those you declared earlier and those declared in the routine If you do not want to specify a value for a required parameter you can pass a null argument by inserting a comma as a placeholder in the argument list If you are passing a parameter using a mechanism other than the default passing mechanism for that data type you must specify the passing mechanism in the CALL statement or the function invocation The following example shows you how to call the external subprogram allocate declared in Section 19 2 2 When allocate is called it is called as a procedure The first parameter must always be a valid LONG INTEGER value the second and third parameters can be of any valid HP BASIC data type EXTERNAL SUB allocate LONG ANY CALL allocate entity a 1 This next example shows you how to call the Run Time Libr
563. tected region and the attached handler if one exists where the error occurred These statements do not return control to the protected region This is known as falling out of the bottom of a handler Be careful not to fall out of the bottom of a handler unintentionally Note that you cannot exit from a handler with the following statements e EXIT PROGRAM e EXIT FUNCTION e EXIT SUB e EXIT DEF e GOSUB with a target outside the handler e GOTO with a target outside the handler Also you cannot exit from a handler with a RESUME statement The RESUME statement is valid only in blocks of code referred to by ON ERROR statements Section 15 3 describes the ON ERROR statements Handling Run Time Errors 15 7 15 2 3 1 15 2 3 2 RETRY Statement You use the RETRY statement to clear the error and to execute the statement again that caused the error again Be sure to take corrective action before trying the protected statement again For example DECLARE REAL radius WHEN ERROR USE fix it INPUT Please supply the radius of the circle radius END WHEN HANDLER fix it trap overflow error IF ERR 48 PRINT Please supply a smaller radius RETRY END HANDLER PRINT The circumference of the circle is 2 PI radius In FOR NEXT loops if the error occurs while HP BASIC is evaluating the limit or increment values RETRY reexecutes the FOR statement if the error occurs while HP BASIC is evaluating the index variable RETR
564. tems those differences are noted The term 164 BASIC refers to HP BASIC on OpenVMS I64 systems Alpha BASIC refers to HP BASIC on OpenVMS Alpha systems VAX BASIC refers to VAX BASIC on OpenVMS VAX systems Intended Audience This manual is intended for programmers who compile link and execute HP BASIC programs on OpenVMS systems Users should have a working knowledge of BASIC or another high level programming language the Digital Command Language DCL and DCL command procedures Document Structure This manual contains the following chapters and appendixes Part Developing HP BASIC Programs on OpenVMS Systems Chapter 1 provides a brief overview of HP BASIC Chapter 2 describes how to develop programs at DCL command level and how to generate a compiler listing Chapter 3 describes how to use the OpenVMS Debugger to debug HP BASIC programs xix XX Part II HP BASIC Programming Concepts Chapter 4 explains how to get started with HP BASIC Chapter 5 explains simple input and output procedures Chapter 6 shows how to use arrays Chapter 7 explains data definitions Chapter 8 explains how to create user defined data structures with the RECORD statement Chapter 9 shows how to control the flow of program execution Chapter 10 explains how to use functions Chapter 11 explains how to handle strings Chapter 12 describes structured programming techniques Chapter 13 explains how to manage files Chapter
565. th of the segment is greater than the length of the input string HP BASIC returns the string that begins at the specified starting character position and includes all characters remaining in the string e Ifthe length of the segment is less than or equal to zero MID returns a null string e Ifyou specify a floating point expression for the position of the segment s first character or for the length of the segment HP BASIC truncates it to a long integer 11 6 5 STRINGS Function The STRING function creates a character string containing multiple occurrences of a single character In the following example 23 is the length of the returned string and 30 is the ASCII value of the character that makes up the string This value is treated modulo 256 STRINGS 23 30 The following example creates a 10 character string containing uppercase As which have ASCII value 65 out STRINGS 10 65 PRINT out END Output AAAAAAAAAA Keep these considerations in mind when you use STRING e Ifthe length of the returned string is less than or equal to zero STRING returns a null string e Ifthe length of the returned string is greater than 65535 HP BASIC signals an error String Handling 11 15 11 6 6 SPACE Function The SPACE function creates a character string containing spaces In this example 5 is the number of spaces in the string SPACES 5 The following example creates a 9 character string which contains 3 space
566. that are used in many programs placing the routines in object module libraries or shareable image libraries lets you access them at link time You do not need to include the routines in the source code thus shortening compilation time and conserving disk space If you have routines that are used simultaneously by many different programs placing the routines in installed shareable images can improve performance at run time conserve main physical memory and reduce paging I O because one copy of the executable code is shared by all users When you link programs object module libraries shareable image libraries and shareable images can contain object code created by any native mode compiler or assembler For more understanding of libraries and shareable images see the HP OpenVMS Linker Utility Manual and the Guide to Creating OpenVMS Modular Procedures For more information about installing shareable images see the HP OpenVMS System Manager s Manual For information about text libraries see Chapter 16 Libraries and Shareable Images 20 1 20 2 System Supplied Libraries If symbols are unresolved after the OpenVMS Linker linker searches all user supplied libraries the linker goes on to search the files in the default system library The OpenVMS system supplies the following libraries System Library Description IMAGELIB OLB Contains symbol tables for all Run Time Library RTL shareable images that are part of the OpenVMS ope
567. that depend on compiled module entities only if the compilation generates an object file Therefore compiled module entities are not generated if you specify the NOOBJECT qualifier on the command line or if the program has compilation errors Dictionary Relationships Relationships occur in a CDO format dictionary when two or more CDO entity definitions are connected in any of several possible ways For example you can relate a set of field definitions to a record definition by including the field names in the record definition See the CDD Repository documentation for detailed information about relationships in a CDO format dictionary Extracting CDD Repository Data Definitions A data definition is one type of a CDD Repository object In HP BASIC you can extract only data definition objects into your program To extract a CDD Repository data definition in HP BASIC specify the INCLUDE FROM CDD compiler directive and a CDD Repository path name You can use this to extract a data definition from either a DMU format or CDO format dictionary For example SINCLUDE FROM CDD CDDSTOP BASIC BASICDEF The INCLUDE FROM CDD directive extracts the CDD Repository data definition you specify and translates it into HP BASIC syntax In HP BASIC the syntax for data definitions or data structures is defined by the RECORD statement After a CDD Repository data definition is translated into RECORD statement syntax you can reference the
568. that the minimum value of y is less than the maximum value of y CORFILSTR Corrupted file structure ERR 29 Explanation RMS has detected an invalid file structure on disk User Action See your system manager DATFORERR Data format error ERR 50 Explanation The program specifies a data type in a statement that does not agree with the value supplied or invalid data was used in string arithmetic User Action Change the statement or supply data of the correct type B 4 Run Time Messages DATOVERF data overflow ERR 289 Explanation The keystroke retrieved by the INKEY function caused the type ahead buffer to overflow or the terminal attempted to send a valid ANSI escape sequence that did not correspond to a keystroke User Action Specify the DCL command SET TERMINAL HOSTSYNC before using the INKEY function This command will prevent the type ahead buffer from overflowing DATTYPERR Data type error ERR 101 Explanation The program attempts to access a parameter passed BY DESC by descriptor and the descriptor contains an incorrect data type This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Check the program code that created the passed parameter and make sure it creates a parameter of correct data type DEADLOCK Detected deadlock while waiting for GET or FIND ERR 193 Explanation The record your program is trying to access is currentl
569. that the compiler is running on for example EV56 instructions on an EV56 processor and EV4 instructions on an EV4 processor e ARCHITECTURE EV4 generates instructions for the EV4 processor 21064 21064A 21066 and 21068 Alpha chips Programs compiled with this option will not incur any emulation overhead on any Alpha processor e ARCHITECTURE EV5 generates instructions for the EV5 processor some 21164 Alpha chips 2 4 Developing HP BASIC Programs Programs compiled with this option will not incur any emulation overhead on any Alpha processor ARCHITECTURE EV56 generates instructions for the EV56 processor some 21164 Alpha chips This option permits the compiler to generate any EV4 instruction plus any instructions contained in the BWX extension Programs compiled with this option might incur emulation overhead on EV4 and EV5 processors Note that the EV5 and EV56 processor both have the same chip number 21164 ARCHITECTURE PCA56 generates instructions for the PCA56 processor 21164PC Alpha chip This option permits the compiler to generate any EV4 instruction plus any instructions contained in the BWX extension Note that currently HP BASIC does not generate any of the instructions in the MAX extension to the Alpha architecture Programs compiled with this option might incur emulation overhead on EV4 and EV5 processors ARCHITECTURE EV6 generates instructions for the EV6 processor 21264 Alpha chip
570. that two errors were detected on line 10 HP BASIC displays the line containing the error then prints a picture showing you where the errors were detected In the example the picture shows a 1 under the keyword BYTE and a 2 under the second occurrence of variable A The following line shows you e The error mnemonic CONDATSPC e Which error in the line s picture is referred to by the mnemonic e The message associated with that error In this case the error message tells you that there are two contradictory data type keywords in the statement The next line shows you the same type of information for the second error in this case the compiler detected multiple declarations of variable A If a compilation causes an error of severity I or W the compilation continues and produces an object module If a compilation causes an error of severity E the compilation continues but produces no object module If a compilation causes an error of severity F the compilation aborts immediately The following is an alphabetized list of compilation error messages ACTARGMUS actual argument must be specified Explanation ERROR A DEF function reference contains a null argument for example FNA 1 2 User Action Specify all arguments when referencing a DEF function A 2 Compile Time Error Messages ALLOCSML allocated area may be too small for section Explanation WARNING A MAP or COMMON with the same name exists in more than one program
571. the current values of X Y and Z on one line because a comma follows the last item in the line PRINT X Y INPUT X Y Z PRINT X Y PRINT Z END Output 5 10 15 5 10 15 The following example shows PRINT statements using a comma a semicolon and no formatting character after the last print item No comma after I so each element Prints on its own line PRINT I FOR I 1 TO 10 PRINT A comma follows J so each element prints in a separate zone MARGIN 80 PRINT J FOR J 1 TO 10 PRINT 5 10 Simple Input and Output A semicolon follows K so print elements are packed together l PRINT K FOR K 1 TO 10 END Output 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 Commas and semicolons also let you control the placement of string output For example PRINT first zone third zone fifth zone END Output first zone third zone fifth zone The extra comma between strings causes BASIC to skip another print zone In the following example the first string is longer than the print zone When the two strings are printed the second string begins in the third print zone because that is the next available print zone after the first string is printed PRINT abcdefghijklmnopqrstuvwxyz pizza PRINT first zone second zone third zone Output abcdefghijklmnopqrstuvwxyz pizza first zone second zone third zone Simple Input and O
572. the two input lists first_list and second_list must have identical dimensions The elements of the new list swm_list equal the sum of the corresponding elements in the input lists MAT sum list first_list second_list You can also subtract the elements of two arrays The following program subtracts one array from another DIM first_array 30 30 DIM second_array 30 30 DIM difference array 30 30 MAT difference array first_array second_array Each element of difference_array is the arithmetic difference of the corresponding elements of the input arrays 6 7 1 3 Multiplication You can multiply the elements of two arrays provided that the number of columns in the first array equals the number of rows in the second array The resulting array contains the dot product of the two input arrays DIM A 2 2 B 2 2 C 2 2 A 1 1 A 1 2 A 2 1 2 2 1 1 1 2 2 1 2 2 MATC A B MAT PRINT C w w w w Pp nou ou tow wt wea OAD BWNYE 19 22 43 50 You can also multiply a matrix by a scalar quantity BASIC multiplies each element of the input array by the scalar quantity you supply The output array has the same dimensions as the input array Enclose the scalar quantity in parentheses The following example multiplies the elements of inch_array by the inch to centimeter conversion factor and places these values in cm_array 6 20 Arrays DIM inch array 5 cm array 5 MAT READ inch array DATA 1 12 36 100
573. the FOR statement 3 16 Using the OpenVMS Debugger with BASIC Step through one iteration of the loop Request the contents of the variable Number The debugger shows the contents of the loop index to be 10 Step through another iteration of the loop Examine the value of the loop index again The debugger shows that the loop index is still 10 The loop index has not changed from its initial setting in the FOR statement Deposit the correct value into Number Step through another iteration of the loop Examine the contents of Number again Observe that the number has not been changed yet Step through just one statement to discover what is interfering with the value of Number during execution of the loop Observe that this statement does not affect the value of Number Step through another statement in the loop Observe that this statement counteracts the change in the loop index eee 8eBGB8B OOOO Exit from the debugger You can now edit the program to delete line 9 and reprocess the program Alternatively you could use the EDIT command while in the debugger environment This debugging session shows that the FOR NEXT loop index Number is not being changed correctly An examination of the statements in the loop shows that the variable Number is being decreased by one during each execution of the FOR statement but incremented by one with each execution of the loop statements From this you can determine that the loop in
574. the SUB FUNCTION or DEF statement specifies User Action Change the specified data type in either the declaration or the SUB FUNCTION or DEF statement so that the data types agree PARMODCHA mode for parameter lt n gt of routine lt name gt changed to match declaration Explanation INFORMATION The data type specified in a routine invocation does not match that of the routine declaration HP BASIC issues this message only if the data type conversion results in a parameter that cannot be modified by the routine that was invoked User Action Make the data type specifications in the declaration and the invocation match A 68 Compile Time Error Messages PARMODNOT mode for parameter lt n gt of routine lt name gt not as declared Explanation ERROR The CALL or invocation of a routine specifies a string argument for a parameter that was specified as a numeric when the routine was declared or vice versa User Action Change the string parameter to numeric or vice versa PARNOTENT parenthesis illegal entire array required context Explanation ERROR Parenthesis are used to specify an entire array in a context where an entire array is always required User Action Remove the empty parenthesis from the entire array reference PARSTRNOT parameter lt n gt of lt type gt structure not as declared Explanation ERROR The actual parameter list in subprogram CALL or an invocation specifies an entire array where the subprog
575. the current record provided that you have write access to that record In order to successfully update a variable length record you must know the exact size of the record you want to update BASIC has access to this information after a successful GET operation If you have not performed a successful GET operation on the variable length record then you must specify a COUNT clause in the UPDATE statement that contains the record size information If you are updating a variable length record and the record that you want to write out is of different size than the record you retrieved you must use a COUNT clause File Input and Output 13 21 An UPDATE will fail with the exception No current record ERR 131 if you have not previously established a current record with a successful GET or FIND Therefore when updating records you should include error trapping in your program to make sure all GET operations execute successfully An UPDATE operation on a sequential file is valid only when e The file containing the record is on disk e The new record is the same size as the one it is replacing e You have established a current record through a GET or FIND operation Note that COUNT defaults to the size of the current record if a GET was performed If a FIND operation was used to locate the current record then you must supply a COUNT value The following program searches to find a record in which the L_name field matches the specified Sear
576. the error Cannot open file ERR 162 18 4 2 Task to Task Communication HP BASIC supports task to task communication if your account has NETMBX privileges Follow these steps for task to task communication 1 Establish a command file at the remote site to execute the program you want The program must be in executable image format For example you can create the file MARG COM at the remote site MARG COM contains a line to run an image in this case COPYT EXE RUN COPYT The OPEN statements in the programs at both nodes must specify the same file attributes 2 Start task to task communication by accessing the command file at the remote site For example a program at the local node could contain the following line OPEN WESTON TASK MARG AS FILE 1 SEQUENTIAL 3 The system then assigns the logical name SYS NET to the program at the local node At the remote node the program COPYT EXE must use this logical for all operations For example OPEN SYSSNET FOR INPUT AS FILE 1 SEQUENTIAL 4 The two programs can then exchange messages The programs must have a complementary series of send receive statements 18 16 Advanced File Input and Output Local Program MAP SJK MSG 32 OPEN WESTON DAVIS PSWRD TASK MARG amp FOR OUTPUT AS FILE 1 SEQUENTIAL MAP SJK LINPUT WHAT IS THE CUSTOMER NAME MSG PUT 1 GET 13 PRINT MSG CLOSE 1 END Remote Node Program 10 MAP SJK
577. the expression so that its value is within the allowable range or select as the default REAL size a floating point data type that has a greater range FNEWHINOT exit from DEF while not in DEF Explanation ERROR An FNEXIT or EXIT DEF statement has no preceding DEF statement User Action Define the function before inserting an FNEXIT or EXIT DEF statement A 32 Compile Time Error Messages FNEWITDEF end of DEF seen while not in DEF Explanation ERROR An FNEND or END DEF statement has no preceding DEF statement User Action Define the function before inserting an FNEND statement or delete the FNEND statement FORFEEMUS FORM FEED must appear at end of line Explanation INFORMATION A form feed character is followed by other characters in the same line User Action Remove the characters following the form feed A form feed must be the last or only character on a line FORPARMUS formal parameter must be supplied for lt name gt Explanation ERROR The declaration of a DEF SUB or FUNCTION routine contains the parentheses for a parameter list but no parameters User Action Supply a parameter list or remove the parentheses FORSTRPAR formal string parameters may not be FIELDed Explanation ERROR A variable name appears both in a subprogram formal parameter list and a FIELD statement in the subprogram User Action Remove the variable from the FIELD statement or the parameter list FOUENDWIT found end of l
578. the logical name LNK LIBRARY If you have more than one library for the linker to search you must number these libraries consecutively otherwise the linker does not search past the first missing logical name The linker allows you to number libraries from 1 to 999 For example DEFINE LNKSLIBRARY USERS SDEV KELLY TESTLIB OLB DEFINE LNKSLIBRARY_1 USER DEV KELLY TESTLIB1 OLB DEFINE LNKSLIBRARY_2 USER DEV KELLY TESTLIB2 OLB After you issue these commands a program executing at DCL level automatically accesses these three library files to resolve program symbols Libraries and Shareable Images 20 3 20 4 Shareable Images Shareable images are not directly executable They contain executable code that can be shared by other images and are intended to be included by the linker in other images The benefits of using shareable images include e Conserving disk storage space e Conserving main physical memory e Reducing paging I O e Allowing shared memory resident databases e Eliminating the need to relink programs that access a new version of a shared routine Note Some of these benefits can only be realized if the shareable image is installed with the OpenVMS Install utility Install To create a shareable image use the SHAREABLE qualifier with the DCL command LINK and specify at least one object module For example LINK SHAREABLE progl This command creates an image that can be linked to othe
579. the valid range for specified data type INVCHASTR Invalid character in string ERR 287 Explanation The program attempts to output a string that contains an invalid character User Action Remove the invalid character from the string Run Time Messages B 17 INVFILOPT Invalid file options ERR 139 Explanation The program has specified invalid file options in the OPEN statement User Action Change the invalid file options INVKEYREF Invalid key of reference ERR 144 Explanation The program attempts to perform a GET FIND or RESTORE on an INDEXED file using an invalid KEY for example an alternate KEY that does not exist for the file that was opened User Action Use a valid KEY in the GET FIND or RESTORE statement INVRFAFIE Invalid RFA field ERR 173 Explanation During a FIND or GET by RFA an invalid record s file address was specified User Action Supply a correct RFA field IO_CHAALR I O channel already open ERR 7 Explanation The program attempted to open a channel in a def or function while I O was pending on that channel User Action Change the function so that it does not open the channel IO_CHANOT I O channel not open ERR 9 Explanation The program attempted to perform an I O operation before opening the channel User Action Open the channel before attempting an I O operation to it KEYFIEBEY Key field beyond end of record ERR 151 Explanation The position given for th
580. three integers A B and C It then passes these variables as parameters to the SUB subprogram The subprogram prints the sum of these variables and returns control to the calling program 12 8 Program Segmentation 12 4 2 PROGRAM get input OPTION TYPE EXPLICIT EXTERNAL SUB SUB01 LONG LONG LONG DECLARE LONG A B C INPUT Please type three integers A B C CALL SUBO1 A B C END PROGRAM SUB SUB01 LONG X LONG Y LONG Z2 PRINT The sum is X Y Z END SUB Invoking FUNCTION Subprograms The following example performs the same task as the SUB program however this example uses a FUNCTION subprogram that returns the value to the main program and the main program prints the result PROGRAM invoke funct EXTERNAL LONG FUNCTION FUNO1 LONG LONG LONG DECLARE LONG A B C INPUT Please type three integers A B C PRINT The sum is FUNO1 A B C END PROGRAM FUNCTION LONG FUNO1 LONG X LONG Y LONG Z FUNOl X Y 2Z END FUNCTION If you do not assign a value to the function name and you do not specify a return value on an EXIT FUNCTION or END FUNCTION statement the function returns zero or the null string Note that when writing FUNCTION subprograms you must specify a data type for the function in both the main program EXTERNAL statement and the subprogram FUNCTION statement This data type keyword specifies the data type of the value returned by the function subprogram You should ensure that the data type spe
581. time error The following example continues the previous one It randomly retrieves the records in a sequential file by using RFAs stored in the array 13 28 File Input and Output DECLARE RFA R array 1 TO 100 DECLARE LONG I MAP XYZ STRING A 80 OPEN TEST DAT FOR OUTPUT AS FILE 1 amp SEQUENTIAL MAP XYZ FOR I 1 TO 1008 PUT 1 R array I GETRFA 1 NEXT T WHILE 1 PRINT Which record would you like to see INPUT type a carriage return to exit Rec numb EXIT PROGRAM IF Rec num 0 GET 1 RFA R array Rec num PRINT A NEXT 13 6 11 Transferring Data to Terminal Format Files The PRINT statement transfers program data to a terminal format file In the following example the INPUT statements prompt the user for three values S_name Area and Quantity Once these values are entered the PRINT statement writes these values to a terminal format file that is open on channel 4 FOR I 1 TO 10 INPUT Name of salesperson S name INPUT Sales district AreaS INPUT Quantity sold Quantity PRINT 4 S name Area Quantity NEXT I If you do not specify an output list in the PRINT statement a blank line is written to the terminal format file A PRINT statement without a channel number transfers program data to a terminal See Chapter 5 for more information 13 6 12 Resetting the File Position The RESTORE statement resets the current record pointer to the beginning of the fil
582. tine procedure and function are used throughout this chapter A routine is a closed ordered set of instructions that performs one or more specific tasks Every routine has an entry point the routine name and may or may not have an argument list Procedures and functions are specific types of routines a procedure is a routine that does not return a value while a function is a routine that returns a value by assigning that value to the function s identifier System routines are prewritten OpenVMS routines that perform common tasks such as finding the square root of a number or allocating virtual memory You can call any system routine from HP BASIC provided that the data structures necessary for that routine are supported The system routines used most often are OpenVMS Run Time Library routines and system services System routines which are discussed later in this chapter are documented in detail in the OpenVMS Run Time Library Routines Volume and the HP OpenVMS System Services Reference Manual 19 1 Specifying Parameter Passing Mechanisms When you pass data between routines that are not written in the same language you have to specify how you want that data to be represented and interpreted You do this by specifying a parameter passing mechanism The general parameter passing mechanisms and their keywords in HP BASIC are as follows e By reference BY REF Using BASIC in the Common Language Environment 19 1 19 1 1 19 1 2
583. ting representation in place of D_floating representation Alpha BASIC and the Alpha system hardware use G_floating representation in place of the D_floating representation Thus the behavior of floating point computations and comparisons can be different from what you expect Data Representation 17 5 17 2 3 17 2 4 GFLOAT Floating Point Number Format G_floating The G_floating floating point number format consists of eight contiguous bytes starting on an arbitrary byte boundary as shown in Figure 17 7 Bits are labeled from the right 0 to 63 The form of a G_floating number is sign magnitude with bit 15 the sign bit bits 14 to 4 an excess 1024 binary exponent and bits 3 to 0 and 63 to 16 a normalized 53 bit fraction with the redundant most significant fraction bit not represented Within the fraction bits increase in significance from 48 to 63 32 to 47 16 to 31 and 0 to 3 The 11 bit exponent field encodes the values 0 to 2047 An exponent value of 0 together with a sign bit of 0 indicates that the G_floating number value is 0 Exponent values from 1 to 2047 indicate true binary exponents from 1023 to 1023 The value of a G_floating number is in the approximate range 56 107808 to 9 1028 the precision is approximately one part in 252 approximately 15 decimal digits Note that both double and G_floating formats require 8 bytes The G_floating format provides a greater range but less precision than double precision fo
584. tion Do not use the feature NOTRANACC Not a random access device ERR 64 Explanation The program attempts a random access on a device that does not allow such access for example a PUT with a record number to a magtape file User Action Make the access sequential instead of random or use a suitable I O device NO_CURREC No current record ERR 131 Explanation The program attempts a DELETE or UPDATE when the previous GET or FIND failed or no previous GET or FIND was done User Action Correct the cause of failure for the previous GET or FIND or make sure a GET or FIND was done then retry the operation NO_PRIKEY No primary key specified ERR 150 Explanation The program attempts to create an INDEXED file without specifying a PRIMARY KEY value User Action Specify a PRIMARY KEY NO_ROOUSE No room for user on device ERR 4 Explanation No user storage space exists on the specified device User Action Delete files that are no longer needed NUMCOOINS Number of coordinates insufficient ERR 281 Explanation Insufficient coordinates are provided A GRAPH POINTS statement requires the coordinates for at least one point A GRAPH LINES statement requires a minimum of two points A GRAPH AREA statement requires a minimum of three points User Action Supply an adequate number of points B 22 Run Time Messages ONEOR_TWO One or two dimensions only ERR 102 Explanation The program contains a MAT statement th
585. tion within a picture definition The following statements are invalid within pictures and within routines that are called by pictures SET WINDOW SET VIEWPORT SET DEVICE WINDOW SET DEVICE VIEWPORT SET TRANSFORMATION SET INPUT PRIORITY SET CLIP User Action Remove any invalid statements from the picture definition Set the boundaries for windows and viewports before a picture is invoked ILLPOISTY Illegal point style number ERR 276 Explanation The specified point style is less than or equal to zero User Action Specify a valid point style greater than or equal to zero ILLRECACC Illogical record accessing ERR 152 Explanation The program attempts to perform an operation that is invalid for the specified file type for example a random access on a sequential file User Action Supply a valid operation for that file type or change the file type ILLRECFIL Illegal record on file ERR 142 Explanation A record contains an invalid byte count field User Action Use the DCL command DUMP to check the file for possible bad data B 14 Run Time Messages ILLRECLOC illegal record locking ERR 187 Explanation The program contains an ALLOW clause on a GET statement and the file was not opened with the UNLOCK EXPLICIT clause This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Either remove the ALLOW clause from the GET statement or use the UNLOCK
586. tions e Terminal format e Sequential e Relative e Indexed e Virtual 13 2 File Input and Output 13 2 1 13 2 2 13 2 3 If you do not specify a file organization when creating a file the default is a terminal format file a sequential file with variable length records The following sections describe each type of file organization Terminal Format Files A terminal format file is a sequential file of variable length records Terminal format files are the default that is you create a terminal format file when you do not specify a file organization when you open a file You can then use the PRINT INPUT INPUT LINE and LINPUT statements to access a terminal format file See Chapter 5 and Chapter 6 for more information about terminal format files Sequential Files A sequential file contains records that are stored in the order they are written Sequential files can contain records of any valid BASIC record format fixed length variable length or stream You usually read a sequential file from the beginning therefore a sequential file is most useful when you access the data sequentially each time you use it You can also access sequential fixed length records randomly by specifying a record number if the file resides on disk In either case sequential files can reside on both disk and magnetic tape devices and those stored on disk support shared access Relative Files A relative file contains a series of cells that are
587. to many system routines is the condition value SS _NORMAL which indicates that the routine completed normally and successfully You can test for this condition value as follows ret status SMGSCREATE PASTEBOARD pb id IF ret status lt gt SS NORMAL THEN CALL LIB STOP ret status BY VALUE END IF Because all success codes have odd values you can check a return status for any success code For example you can cause execution to continue only if a success code is returned by including the following statements in your program ret status SMGSCREATE PASTEBOARD pb id IF ret status AND 1 0 THEN CALL LIB STOP ret status BY VALUE END IF In general you can check for a particular success or failure code or you can test the condition value returned against all success codes or all failure codes 19 5 Examples of Calling System Routines This section provides complete examples of calling system routines from HP BASIC In addition to the examples provided the VMS Run Time Library Routines Volume and the HP OpenVMS System Services Reference Manual also provide examples for selected routines See these manuals for help about the use of a specific system routine Example 19 3 uses a function that invokes the SYS TRNLNM system service SYS TRNLNM translates a logical name to an equivalence name It places the equivalence name string into a string variable you supply in the parameter list System services never change a s
588. tring variable s length Therefore if you use a system service that returns a string be sure that the receiving string variable is long enough for the returned data You can make sure of this in one of two ways e Define the string variable s length in a MAP COMMON or RECORD definition Using BASIC in the Common Language Environment 19 19 e Assign a long string to the variable for example A SPACE 80 This pre extends the variable so that it is long enough to receive all of the returned data Example 19 3 Calling System Services 10 This function attempts to translate a logical name while searching through all of the tables defined in LNM DCL LOGICAL If the translation lis successful S TRNLNM returns the equivalence name string FUNCTION STRING Translate STRING Logical_name EXTERNAL LONG FUNCTION SYSSTRNLNM LONG STRING STRING LONG ITEM LIST EXTERNAL LONG CONSTANT LNM M_CASE_ BLIND LNM _STRING SS _NORMAL Declare the parameters DECLARE LONG attributes amp trans status DECLARE WORD equiv len Declare the value returned by the function DECLARE LONG CONSTANT Buffer length 255 RECORD item list GROUP item 1 VARIANT CASE WORD Buf_len WORD Code LONG Buffer address LONG Length address CASE LONG Terminator END VARIANT END GROUP item END RECORD item list Declare an instance of the record DECLARE ITEM LIST TRNLNM_ ITEMS Define a common area for Translation_buffer COMMON Trans buffer
589. truncates the new value to fit the destination string Similarly if you use LSET or RSET to concatenate strings you must ensure that the destination variable is long enough to receive the data The LET LSET and RSET statements all operate on dynamic strings as well as fixed length strings The LET statement can change the length of a dynamic string LSET and RSET do not LSET and RSET are more efficient than LET when changing the value of a dynamic string For more information about LSET and RSET see Section 11 5 2 and Section 11 5 3 In the following example the first line assigns the value ABC to A the second line assigns XYZ to B and the third line assigns six spaces to C These variables are dynamic strings In the fourth line LSET assigns A the value of A concatenated with B Because the LSET statement does not change the length of the destination string variable only the first three characters of the expression A B are assigned to A The fifth line uses LSET to assign C the value of A concatenated with B Because C already has a length of 6 this statement assigns the value ABCXYZ to it 11 2 String Handling LET AS ABC LET B XYZ LET C LSET A LSET C PRINT A PRINT C END Output ABC ABCXYZ Like the LET statement the INPUT INPUT LINE and LINPUT statements can change the length of a dynamic string but they cannot change the length of a fixed length string AS B
590. ts depending on the size of the data to be stored These formats include SINGLE floating point DOUBLE floating point GFLOAT floating point SFLOAT floating point TFLOAT floating point XFLOAT floating point and packed DECIMAL format The following sections describe each of these formats SINGLE Floating Point Number Format F_floating F floating single precision floating point numbers are stored as four contiguous bytes starting on an arbitrary byte boundary Bits are labeled from the right 0 to 31 The format for single precision is sign magnitude with bit 15 the sign bit bits 14 to 7 an excess 128 binary exponent and bits 6 to 0 and 31 to 16 a normalized 24 bit fraction with the redundant most significant fraction bit not represented See Figure 17 5 for the format The 8 bit exponent field encodes the values from 0 to 255 inclusively Data Representation 17 3 17 2 2 An exponent value of 0 together with a sign bit of 0 indicates that the F_floating number has a value of 0 Exponent values from 1 to 255 indicate true binary exponents of 127 to 127 An exponent value of 0 together with a sign bit of 1 is taken as reserved Floating point instructions processing a reserved operand take a reserved operand fault The magnitude of an F_floating number is in the approximate range 29 10788 to 1 7 1028 The precision of an F_floating number is approximately one part in 223 approximately 7 decimal digits Figure 17 5 S
591. tures 8 7 END GROUP Executive END VARIANT END RECORD Declarations DECLARE Emp wage class Emp Main Program logic starts here Use LINPUT statements for string fields so the entire string is assigned to the variable LINPUT Name Emp Emp name LINPUT Street Emp Street LINPUT State Emp State INPUT Zip Code Emp Zip LINPUT Wage Class Emp Wage class SELECT Emp Wage_ class CASE A INPUT Rate Emp Hourly wage INPUT Regular pay Emp Regular pay ytd INPUT Overtime pay Emp Overtime pay ytd CASE B INPUT Salary Emp Salaried yearly salary INPUT Pay YTD Emp Salaried pay_ytd CASE C INPUT Salary Emp Executive yearly salary INPUT Pay YTD Emp Executive pay ytd INPUT Expenses Emp Expenses_ytd END SELECT Variant fields can appear anywhere within the RECORD instance When you use RECORD variants you imply that any RECORD instance can contain any one of the listed variants Therefore if each variant requires a different amount of space BASIC uses the case that requires the most storage to determine the space allocated for each RECORD instance 8 1 3 Accessing RECORD Components To access a particular elementary component within a RECORD that contains other groups you use the name of the declared RECORD instance the group name or group names if groups are nested and the elementary component name each separated by double colons In the
592. tus from RMS User_fab Address of RMS File Access Block User_rab Address of RMS Record Access Block Channel Logical Unit assigned to file by caller FORMAL PARAMETERS Standard for all BASIC USEROPEN procedures RETURN VALUE RMS Status value l l l GLOBAL COMMON USAGE l RAB ptr Single longword PSECT used to pass RAB address to caller OPTION INACTIVE SETUP amp CONSTANT TYPE INTEGER amp TYPE EXPLICIT SNOLIST SINCLUDE FABDEF FROM LIBRARY SYSSLIBRARY BASICSSTARLET SINCLUDE RABDEF FROM LIBRARY SYSSLIBRARY BASICSSTARLET SINCLUDE RMSDEF FROM LIBRARY SYSSLIBRARY BASICSSTARLET SINCLUDE STARLET FROM LIBRARY SYSSLIBRARY BASICSSTARLET LIST Common area used to pass RAB address to caller Ca COMMON RAB ptr LONG rab address DECLARE LONG Rms_status 1 Save RAB address in global symbol known to caller Perform standard RMS open sequence la Rab address LOC User_rab rab b_ bid Rms_ status SysSopen User fab continued on next page 13 42 File Input and Output Example 13 1 Cont Creating a USEROPEN Routine IF Rms status Rms normal THEN Rms status SysSconnect User rab END IF END FUNCTION Rms_status Note You cannot use a USEROPEN routine to fill the RBF UBF BKS or CTX fields in the RAB These fields are filled in after the USEROPEN routine returns any values placed there by the USEROPEN routine
593. type HP BASIC converts the actual argument supplied to the specified data type For example if you supply an integer argument to a function that expects a floating point number HP BASIC converts the argument to a floating point number Floating point arguments that are passed to integer functions are truncated not rounded The following sections discuss the HP BASIC built in numeric functions ABS Function The ABS function returns a floating point number that equals the absolute value of a specified numeric expression For example READ A B DATA 10 35 3 NEW A ABS A PRINT NEW A ABS B END Output 10 35 3 The ABS function always returns a number of the default floating point data type INT and FIX Functions The INT function returns the floating point value of the largest integer less than or equal to a specified expression The INT function always returns a number of the default floating point type The FIX function truncates the value of a floating point number at the decimal point FIX always returns a number of the default floating point type The following example shows the differences between the INT and FIX functions Note that the value returned by FIX 45 3 differs from the value returned by INT 45 3 PRINT INT 23 553 FIX 23 553 PRINT INT 3 1 FIX 3 1 PRINT INT 45 3 FIX 45 3 PRINT INT 11 FIX 11 END 10 2 Functions 10 1 1 3 Output 23 23 3 3 46 45 11 11 SIN COS and T
594. u do intend to debug your program in immediate mode make the routine that you want to debug the last compilation unit in the source file The symbols for the last compilation unit are always available Alternatively use the OpenVMS Debugger to debug your program NOHANSPE no handler specified for WHEN block Explanation ERROR A WHEN block has been found that does not specify an error handler User Action Specify an error handler for the WHEN block NOLINENUM missing line number on first line Explanation WARNING There is no line number on the first line of the program User Action Add a line number to the first line of the program or remove all line numbers from the program A 62 Compile Time Error Messages NOLNROOM out of memory for line numbers Explanation ERROR The program contains more line numbered statements than HP BASIC allows User Action Change the program so that it uses multistatement lines instead of having each statement on its own line or split the program into one or more program units in separate files NOMAPNAME MAP statement requires map name Explanation ERROR A MAP statement does not specify a map name User Action Specify a name for the MAP NOSCAFILE unsaved changes no analysis file produced Explanation WARNING The program in memory contains changes that have not been saved therefore no data analysis file will be produced from this compilation User Action SAVE or REPLAC
595. u do not specify the number of characters to substitute HP BASIC attempts to insert the entire source expression However the MID statement never changes the length of the target string variable therefore the entire source expression might not fit into the available space The following example shows the use of MID as an assignment statement In this example ABCD is the input string the starting character position is 1 and the length of the segment to be replaced is 3 characters Note that when you use MID as an assignment statement the length of the input string does not change therefore the length of the result 123D is equal to the length of the input string DECLARE STRING old string replace string old string ABCD z replace string 123 PRINT old string MID old string 1 3 replace string PRINT old string 11 8 String Handling Output ABCD 123D Keep these considerations in mind when you use the MID assignment statement e The length argument is optional If not specified the number of characters replaced will be the minimum of the length of the replacement string and the length of the input string minus the starting position value e Ifthe length of the segment is less than or equal to zero HP BASIC assumes a length of zero e The length of the input string does not change regardless of the value of the length of the segment 11 6 Manipulating String Data with String Functions 11
596. uage environment 19 1 to 19 23 COMMON statement 6 6 7 5 sharing arrays with 6 6 with subprograms 7 11 Communication task to task 18 16 Compilation controlling with LET directive 16 8 terminating with ABORT directive 16 10 Compilation listing with INCLUDE 16 8 with SHOW 2 16 Compiled module entity recording 21 7 Compiler listing 2 21 Compiler directives 16 1 to 16 12 benefits of 16 1 conventions of 16 1 listing 16 2 Compiling DEBUG 3 1 Component of a RECORD 8 2 Concatenation 7 11 Conditional expressions in IF THEN ELSE statement 9 10 in WHILE NEXT loops 9 7 Condition values 19 19 Constants declaring 7 3 definition of 7 3 string 11 1 CONTINUE statement 15 8 Control structures 9 1 to 9 20 Control variable loop 9 38 COS function 10 3 CROSS directive 16 6 CROSS_REFERENCE qualifier 2 7 Ctrl C trapping 10 16 15 17 to 15 18 CTRLC function 10 16 15 17 Currency symbol with PRINT USING statement 14 9 Current record pointer resetting with RESTORE statement 13 29 setting with FIND statement 13 14 Index 3 D Data formatting with PRINT USING statement 14 1 passing between BASIC and Fortran 19 8 rereading with RESTORE statement 5 7 sharing between modules 5 6 Data blocks 13 1 Data definition 7 1 to 7 15 Data records 13 1 accessing by RFA 13 5 13 27 to 13 29 access modes for 13 5 deleting with DELETE statement 13 21 determining the n
597. ucketsize blocksize WORD Num keys LONG Max record number CASE z STRING Ret string 16 END VARIANT END RECORD DECLARE FSP data File chars OPEN FIL DAT FOR INPUT AS FILE 18 amp ORGANIZATION UNDEFINED amp RECORDTYPE ANY ACCESS READ File chars Ret_string FSPS 1 The following list explains the above example e Rat returns the low byte that is the RMS record attributes RAT field e Org returns the high byte that is the RMS organization ORG field e Max_record_size returns the RMS maximum record size MRS field e File_size returns the RMS allocation quantity ALQ field e Bucketsize_blocksize returns the RMS bucket size BKS field for disk files or the RMS block size BLS field for magnetic tape files e Num_keys returns the number of keys e Max_record_number returns the RMS maximum record number MRN field if the file is a relative file Note that FSP returns zeros in bytes 9 to 12 For more information see the OpenVMS Record Management Services Reference Manual 13 32 File Input and Output 13 7 2 RECOUNT Function 13 7 3 Read operations can transfer varying amounts of data The system variable RECOUNT contains the number of characters bytes read after each read operation After a read operation from your terminal RECOUNT contains the number of characters transferred including the line terminator After accessing a record RECOUNT contains the number of characters in the record RE
598. ulo 256 PRINT THIS PROGRAM FINDS THE CHARACTER WHOSE PRINT VALUE MODULO 256 YOU TYPE INPUT values PRINT CHR values END Output 1 THIS PROGRAM FINDS THE CHARACTER WHOSE VALUE MODULO 256 YOU TYPE 69 E Output 2 THIS PROGRAM FINDS THE CHARACTER WHOSE VALUE MODULO 256 YOU TYPE 1093 E String Numeric Functions Numeric strings are numbers represented by ASCII characters A numeric string consists of an optional sign a string of digits and an optional decimal point You can use E notation in a numeric string for floating point constants The following sections describe some of the HP BASIC numeric string functions Functions 10 7 10 1 3 1 FORMAT Function The FORMAT function converts a numeric value to a string The output string is formatted according to a string you provide The expression you give this function can be any string or numeric expression The format string must contain at least one PRINT USING format field The formatting rules are the same as those for printing numbers with PRINT USING See Chapter 14 for more information about the PRINT USING statement and formatting rules A 5 BS Z FORMATS A B PRINT Z END Output 5 00 10 1 3 2 NUMS and NUM1 Functions The NUM function evaluates a numeric expression and returns a string of characters formatted as the PRINT statement would format it The returned numeric string is preceded by one space for positive number
599. ult at a terminal NO MACHINE_CODE NOMACHINE_CODE default The MACHINE_CODE qualifier specifies that the listing file includes the compiler generated object code 2 10 Developing HP BASIC Programs Remarks e MACHINE_CODE specifies that the compiler include a listing of the compiler generated object code in the listing file If the LISTING qualifier is not specified as well MACHINE is ignored e NOMACHINE_CODE specifies that the listing file not include compiler generated object code NOJOBJECT file spec OBJECT default The OBJECT qualifier causes the compiler to produce an object module and optionally specifies its file name By default the compiler generates object files as follows e Ifyou specify one source file BASIC generates one object file e If you specify multiple source files separated by plus signs BASIC appends the files and generates one object file e If you specify multiple source files separated by commas BASIC compiles and generates a separate object file for each source file e You can use both plus signs and commas in the same command line to produce different combinations of appended and separated object files Remarks e OBJECT file spec produces an object file with an explicit file specification Omitting file spec causes the compiler to produce an object file having the same name as its corresponding source file and the file type OBJ All other file specificatio
600. ultiple unit program that does not contain line numbers Program Segmentation 12 7 however any comments following an END END SUB or END FUNCTION statement become part of the following subprogram if one exists In the following example the function Strip changes all brackets to parentheses in the string A or alpha and strips all trailing spaces and tabs PROGRAM scan EXTERNAL STRING FUNCTION Strip STRING AS USERSDISK BASIC TRYOUTS BS Strip AS PRINT B END PROGRAM FUNCTION STRING Strip STRING alpha IF POS alpha 1 gt 0 THEN Strip EDITS alpha 128 64 ELSE Strip EDITS alpha 128 END IF END FUNCTION 12 4 Invoking Subprograms 12 4 1 The following sections describe how to invoke subprograms and pass parameters to subprograms Invoking SUB Subprograms The CALL statement transfers control to a subprogram and optionally passes arguments to it The parameters in the CALL statement specify variables constants expressions array elements or entire arrays to be passed to the subprogram You can also specify a function in the argument list HP BASIC passes the value returned by the function to the subprogram If possible HP BASIC converts the actual arguments to the data type specified in the EXTERNAL statement HP BASIC signals an error when the conversion is not possible The following example shows an HP BASIC main program calling a BASIC subprogram The main program prompts for
601. umber transferred 13 33 fields in 13 1 fixed length 13 1 handling locked conditions 13 18 13 25 locating 13 14 moving with MOVE statement 13 9 next record pointer 13 5 random access by key 13 5 random access by record number 13 5 reading with GET statement 13 16 record context of 13 5 sequential access 13 5 stream format 13 2 variable length 13 2 writing with PUT statement 13 19 Data representation 17 1 to 17 11 DATA statement 5 6 to 5 7 comment fields in 5 6 continuing with ampersand 5 6 Data structures 8 1 to 8 13 Data type and size setting the default 7 2 setting the default with qualifiers 7 2 setting the default with the OPTION statement 7 2 Data type keywords with FILL 7 10 Index 4 Data types 4 6 BYTE 4 7 DECIMAL 4 7 definition of 7 1 INTEGER 4 7 7 1 list of 7 1 LONG 4 7 packed decimal 4 7 REAL 4 7 RFA 4 7 STRING 4 7 subtypes 4 7 user defined 8 1 WORD 4 7 DATE function 10 14 DATE4 function 10 14 DCL STATUS 12 10 Deadlock 13 25 Debit and credit notation with PRINT USING statement 14 12 Debugger 3 1 to 3 18 Debugging 3 1 hints 3 17 source code containing an error 3 17 DEBUG qualifier 2 7 3 1 DECIMAL data type 4 7 variables 4 11 Decimal point location with PRINT USING statement 14 5 Decimal scalar string descriptors 17 11 DECIMAL_SIZE qualifier 2 8 Decision blocks controlling 9 1 to 9 20 Decis
602. unction definitions DEF FN A X X 2 3 X 4 DEF FN B X FN A X 2 FN A X DEF FN C X SQR X 4 1 DEF CUBE X X 3 Note that the name of the last function defined does not begin with FN This is valid as long as no reference to the function lexically precedes the function definition You can also define a function that has no formal parameters The following function definition uses three HP BASIC built in functions to return an integer corresponding to the day of the month e DATE 0 returns a date string in the form dd Mmm yy e The SEG function strips out of this value the characters starting at character position 1 up to and including the character at position 2 the day number Functions 10 19 10 2 2 e The VAL function converts this resulting numeric string to an integer In this way fnday_number returns the day of the month as an integer DEF INTEGER fnday number VAL SEG DATE 0 1 2 Multiline DEF Functions The DEF statement can also define multiline functions Multiline DEF functions are useful for expressing complicated functions Note that multiline DEF functions do not have the equal sign and defining expression on the first line Instead this expression appears in the function block assigned to the function name Note If a multiline DEF function contains DATA statements they are global to the program unit Multiline function definitions can contain any constant v
603. upper bound 4 Explanation ERROR The specified transformation matrix either has a lower bound other than 0 or an upper bound other than 4 User Action Declare the matrix such that both dimensions have a lower bound of 0 and an upper bound of 4 MATMUL2OP MAT multiply of 2 4X4 matrices required Explanation ERROR You specified the wrong dimensions in a matrix in the MAT multiply statement or a WITH clause on the DRAW statement or you specified a nonmultiplication operation in a multiple operation MAT arithmetic statement For example MAT A B C D A two dimensional matrix with lower bounds 0 and upper bounds 4 in both dimensions is required User Action Declare the matrix to be a two dimensional matrix with lower bounds 0 and upper bounds 4 in both dimensions A 56 Compile Time Error Messages MATONEOR2 MAT statements require one or two dimensions Explanation ERROR A MAT statement references an array of more than two dimensions User Action Remove the array reference MAT statements are valid only on arrays of one or two dimensions MAXCONCOM maximum conditional compilation depth exceeded Explanation FATAL Too many nested IF THEN ELSE ZEND IF directives are contained in the program User Action Reduce the number of nested IF THEN ELSE END IF directives You can nest up to eight such constructs MAXDIMEXC maximum number of dimensions exceeded Maximum is 32 Explanation ERROR An array declaration spe
604. urce code from another file e Display informational messages during the compilation BASIC also supplies the lexical built in function VARIANT that can be used to conditionally control compilation 16 8 Compiler Directives 16 4 1 IF THEN ELSE END IF uses lexical expressions to determine whether to execute directives in the THEN clause or the ELSE clause The following sections describe the use of e Lexical constants and expressions LET directive e VARIANT e ABORT e PRINT e IF THEN ELSE END IF LET Directive The LET directive creates and assigns values to lexical constants Lexical constants are always LONG integers These constants control the execution of the IF THEN ELSE END IF directive All lexical constants must be created with LET before they can be used in a IF THEN ELSE END IF directive and each lexical constant must be created with a separate LET directive All lexical constant names must also be preceded by a percent sign and cannot end with a dollar sign or percent sign A lexical expression can be any of the following e A lexical constant e An integer literal e A lexical built in function VARIANT e Any combination of these separated by logical relational or arithmetic operators The LET directive lets you create constants that control conditional compilation For example SLET debug on 0 See Section 16 4 5 for an example of using LET with IF THEN ELS
605. urn is typed in response to the prompt DECLARE STRING CONSTANT table amp JANFEBMARAPRMAY JUNJULAUGSEPOCTNOVDEC DECLARE STRING month UPPER CASE MONTH message DECLARE INTEGER month _ length DECLARE REAL month pos PRINT Please type the first three letters of a month PRINT To end the program type only Return Loop_1 WHILE 1 1 INPUT month UPPER CASE MONTH EDIT month 32 month length LEN UPPER CASE MONTH EXIT Loop 1 IF month length 0 IF month length 3 THEN month pos beara UPPER_CASE MONTH 1 2 3 IF month pos 0 OR month pos lt gt FIX month pos THEN MESSAGE Invalid abbreviation try again ELSE MESSAGE is month number NUMS MONTH POS END IF ELSE MESSAGE Abbreviation not three characters try again END IF PRINT month message NEXT END String Handling 11 11 Output Please type the first three letters of a month To end the program type only Return Nov Nov is month number 11 Keep these considerations in mind when you use POS e If you specify a starting position less than 1 POS assumes a starting position of one e If you specify a starting position greater than the searched string s length POS returns a zero unless the substring is null e When searching for a null string If you specify a starting position greater than the strings length POS returns the string s length plus one Ifthe string to be searched is also null POS returns
606. us code for successful completion has a value of one however this code for successful completion is defined in the system library STARLET as the symbol SS _NORMAL A program might compare the status code returned by a system service to either the symbolic constant SS _NORMAL or the integer value one The program would execute the same way in either case In the first case the Using BASIC in the Common Language Environment 19 17 value for SS _ NORMAL is supplied at link time by the OpenVMS Linker In the second case the value 1 is included in the program as a literal constant The advantages of using symbolic definitions are as follows e Because symbolic definition names are mnemonic the program is easier to read and understand e It is easier to write the symbolic definition and let the OpenVMS Linker fill in the value than to look up the value associated with the symbol and include that value in the program e Should the value associated with a symbol ever change you must relink the program To change a hard coded definition you must edit the source file then recompile and relink Symbolic definitions used by system services are located in the default system library STARLET OLB For Run Time Library routines the only time that you need to include symbolic definitions is when you are calling an SMG routine or when you are calling a routine that is a jacket to a system service A jacket routine in the Run Time Library i
607. use Any part of the file specification still missing is filled in from the current default device and directory of the process File Input and Output 13 37 13 8 6 13 8 7 EXTENDSIZE Clause The EXTENDSIZE attribute determines how many disk blocks RMS adds to the file when the current allocation is exhausted The EXTENDSIZE clause only has an effect when creating a file You specify EXTENDSIZE as a number of blocks For example OPEN TSK ORN FOR OUTPUT AS FILE 23 amp ORGANIZATION RELATIVE EXTENDSIZE 128 The EXTENDSIZE clause causes RMS to add 128 disk blocks whenever the current space allocation is exhausted and the file must be extended The value you specify must conform to the following requirements e It must be specified when you create the file e It cannot exceed 65 535 disk blocks If you specify zero the extension size equals the RMS default value The EXTENDSIZE value can be overridden for single OPEN operations FILESIZE Clause With the FILESIZE attribute you can allocate disk space for a file when you create it The following statement allocates 50 blocks of disk space for the file VALUES DAT OPEN VALUES DAT FOR OUTPUT AS FILE 3 FILESIZE 50 Pre extending a file has several advantages e The system can create a complete directory structure for the file instead of allocating and mapping additional disk blocks when needed e You reserve the needed disk space for your application This ensures that
608. users FLOPOIERR Floating point error or overflow ERR 48 Explanation A program operation resulted in a floating point number with absolute value outside the allowable range for that data type User Action Check program logic or trap the error in an error handler Run Time Messages B 9 FNEWITFUN FNEND without function call ERR 73 Explanation The program executes an END DEF or FNEND statement before executing a function call This error cannot be trapped with a HP BASIC error handler unless the program contains OPTION HANDLE SEVERE User Action Check program logic to make sure that END DEF or FNEND statements are executed only in multiline DEFs or remove the END DEF or FNEND statement GKSNOTINS DEC GKS FOR VMS is not installed ERR 226 Explanation Graphics statements are not operational when Compaq GKS is not installed User Action See your system manager ILLALLCLA Illegal ALLOW clause ERR 168 Explanation The value specified for the ALLOW clause sharing on the OPEN statement is illegal for the type of file organization User Action Change the ALLOW clause argument ILLARGLOG Illegal argument in LOG ERR 53 Explanation The program contains a negative or zero argument to the LOG or LOG10 function User Action Supply an argument in the valid range ILLARESTY Illegal area style ERR 262 Explanation Area style must be one of the following e SOLID the default e HOLLOW e HATCH e PATTERN
609. ut does not specify FOR INPUT User Action Specify FOR INPUT in the OPEN statement You cannot create a file with an undefined file organization Compile Time Error Messages A 67 OVFCHKSUP OVERFLOW checking supported only for INTEGER and DECIMAL Explanation ERROR Overflow checking was specified for a floating point data type in 1 a compiler command 2 a qualifier to the DCL BASIC command or 3 an OPTION statement User Action Specify overflow checking only for INTEGER or DECIMAL data types or both OVRNOLINE lt keyword gt overrides NOLINE Explanation WARNING The program 1 was compiled with NOLINES and 2 uses a keyword that requires line number information For example ERL and RESUME with a line number both require that the program be compiled with LINES User Action None If you use a keyword that requires line number information VAX BASIC automatically overrides the NOLINE qualifier PAREXPFOR lt n gt parameters expected for lt routine gt Explanation ERROR The CALL or invocation of a routine specifies a different number of parameters than the number specified when the routine was declared User Action Change the number of parameters to match the number declared PARINCPRE parameter lt name gt inconsistent with previous declaration or reference Explanation ERROR An external subprogram or DEF function declaration specifies a data type for one of the parameters that is different than the data type
610. ut value of number is less than zero the conditional expression is true HP BASIC then executes the statements in the THEN clause skips the statement in the ELSE clause and transfers control to the statement following the END IF If the value of number is greater than or equal to zero the conditional expression is false HP BASIC then skips the statements in the THEN clause and executes the statement in the ELSE clause INPUT Input number number IF number lt 0 THEN number number PRINT That square root is imaginary PRINT The square root of its absolute value is PRINT SQR number ELSE PRINT The square root is SQR number END IF END Output Input number 9 That square root is imaginary The square root of its absolute value is 3 Do not neglect to end an IF THEN ELSE statement After an IF block is executed control is transferred to the statement immediately following the END IF If there is no END IF HP BASIC transfers control to the next line number Code between the keyword ELSE and the next line number becomes part of the ELSE clause If there are no line numbers the HP BASIC compiler ignores the remaining program code from the keyword ELSE to the end of the program Therefore it is important to end IF statements 9 10 Program Control IF THEN ELSE statements can be nested In an inner nesting level if an END IF is not present the BASIC compiler treats the presence of an ELSE clause for an IF s
611. utine 19 21 21 1 CDDL otis ose ees heen eh oe ie E o eee es 21 21 21 2 Translated RECORD Statement 005 21 22 XV Figures 7 1 17 1 17 2 17 3 17 4 17 5 17 6 17 7 17 8 17 9 17 10 17 11 17 12 17 13 Tables xvi 2 1 3 1 4 1 6 1 6 2 7 1 10 1 10 2 11 1 11 2 13 1 13 2 13 3 13 4 14 1 14 2 19 1 19 2 Multiple Maps lt 2 0044 40256 446 40040 0 8246445604 7 9 Byte Length Integer Format anaana 17 1 Word Length Integer Format 0 0 00 0c eee 17 2 Longword Integer Format 0 00 cc eee eens 17 2 Quadword Integer Format 0 0 0 0 cece eee 17 3 Single Precision Real Number Format 17 4 Double Precision Real Number Format 17 5 GFLOAT Floating Point Number Format 17 6 SFLOAT Floating Point Number Format 17 7 TFLOAT Floating Point Number Format 17 7 XFLOAT Floating Point Number Format 17 8 Fixed Length String Descriptor Format 17 10 Dynamic String Descriptor Format 17 11 Decimal Scalar String Descriptor 00005 17 11 Natural Boundaries For Supported Data Types 2 19 Resultant Behavior of the STEP JINTO Command 3 15 Predefined Constants 0 0 0 0 ccc cee eee 4 9 MAT Statements 0 0 6 11 MAT Statement Keywords 0 0 cence eee 6 12 FILL Item Formats Represe
612. utput 5 11 5 2 2 Output Format for Numbers and Strings BASIC prints strings exactly as you type them with no leading or trailing spaces It does not print quotation marks unless they are delimited by another matching pair For example PRINT PRINTING QUOTATION MARKS END Output PRINTING QUOTATION MARKS BASIC follows these rules for printing numbers e When you print numeric fields BASIC precedes each number with a space or a minus sign and follows it with a space e BASIC does not print trailing zeros to the right of the decimal point If all digits to the right of the decimal point are zeros BASIC omits the decimal point as well e When you print LONG integers BASIC prints up to 10 significant digits e When you print DECIMAL values HP BASIC prints up to 31 digits HP BASIC follows these rules for printing floating point numbers e Ifa floating point number can be represented exactly by 6 decimal digits or fewer and optionally a decimal point BASIC prints it that way e When you print a floating point number whose integer portion is 6 decimal digits or less for example 1234 567 BASIC rounds the number to 6 digits 1234 57 If the integer portion of the number is 7 decimal digits or larger BASIC rounds the number to 6 digits and prints it in E format See the HP BASIC for OpenVMS Reference Manual for more information about E format e When you print a floating point number with magnitude from 0 1 to 1
613. variables into the buffer The UPDATE statement writes the record back into file MOV DAT The CLOSE statement closes the file 13 10 File Input and Output 13 6 File and Record Operations 13 6 1 You can perform a variety of operations on files and on the records within a file The following is a list of all the file and record operations supported by BASIC e Open a file for processing with the OPEN statement e Locate a record in a file with the FIND statement e Read a record from a file with the GET statement e Write a record to a file with the PUT statement e Delete a record from a file with the DELETE statement e Change the contents of a record field with the UPDATE statement e Unlock the last record accessed with the UNLOCK statement e Unlock all previously locked records with the FREE statement e Write data to a terminal format file with the PRINT statement e Reset the current record pointer to the beginning of a file with the RESTORE and RESET statements e Delete all the records after a certain point that is truncate the records with the SCRATCH statement e Rename a file with the NAME AS statement e Close an open file with the CLOSE statement e Delete an entire file with the KILL statement Note that before you can perform any operations on the records in a file you must first open the file for processing Opening Files The OPEN statement opens a file for processing specifies the characterist
614. ve the following advantages over line numbers e Meaningful label names provide documentation e You can use labels in programs with or without line numbers When you use a label to mark a program location you must end the label with a colon The colon is used to show that the label name is being defined instead of referenced When you reference the label do not include the colon In the following example the label names end with colons when they mark a location but the colons are not present when the labels are referenced OPTION TYPE EXPLICIT Require declarations DECLARE INTEGER A Outer loop IF A lt gt B THEN Inner loop IF B C THEN A A 1 GOTO Outer loop ELSE B B 1 GOTO Inner loop END IF END IF Labels have no effect on the order in which program lines are executed they are used to identify a statement or block of statements 4 1 4 Continuation of Long Program Statements If a program line is too long for one line of text you can continue the program line by placing an ampersand amp at the end of the line Note that only spaces and tabs are valid between the ampersand and the carriage return BASIC Concepts and Elements 4 3 A single statement that spans several text lines requires an ampersand at the end of each continued line For example OPEN SAMPLE DAT AS FILE 28 amp SEQUENTIAL VARIABLE amp RECORDSIZE 80 In an IF THEN ELSE construction ampersands amp are not necessar
615. ven if the DIM statement contains a data type keyword the array name can still end in the appropriate data type suffix This makes the data type of the array immediately obvious The DIM statement can be either executable or declarative If the specified bounds are constants the DIM statement is declarative This means that the storage is allocated at compile time and the array cannot appear in any other DIM statement However if any of the specified bounds are variables simple or subscripted the DIM statement is executable This means that the storage for the array is allocated at run time and the array can be redimensioned with a DIM statement any number of times Note In the DIM statement bounds can be either constants or variables simple or subscripted but not expressions When an array is redimensioned with the executable DIM statement the array can become larger or smaller than it was However redimensioning an array in this way causes it to be reinitialized and all data in the array is lost 6 4 Arrays In contrast MAT statements let you redimension an array to be the same size or smaller than it was However MAT statements redimension arrays only when assigning values or performing matrix I O therefore the fact that MAT statements reinitialize the array does not matter See Section 6 6 for more information about MAT statements 6 2 2 1 Declarative DIM Statements Declarative DIM statements have integer
616. wing example the value 45 is assigned to the integer variable WIDTH the EVALUATE command then obtains the sum of the current value of WIDTH plus 7 DBG gt DEPOSIT WIDTH 45 DBG gt EVALUATE WIDTH 7 52 DBG gt Following is an example of how the EVALUATE and the EXAMINE commands are similar When the expression following the command is a variable name the value reported by the debugger is the same for either command DBG gt DEPOSIT WIDTH 45 DBG gt EVALUATE WIDTH 45 DBG gt EXAMINE WIDTH SIZE WIDTH 45 Following is an example of how the EVALUATE and EXAMINE commands are different DBG gt EVALUATE WIDTH 7 52 DBG gt EXAMINE WIDTH 7 SIZE WIDTH 131584 With the EVALUATE command WIDTH 7 is interpreted as a language expression which evaluates to 45 7 or 52 With the EXAMINE command WIDTH 7 is interpreted as an address expression 7 bytes are added to the address of WIDTH and whatever value is in the resulting address is reported in this example 131584 3 6 Stepping Into BASIC Routines This section provides details of the STEP INTO command that are specific to BASIC In the following example the debugger is waiting to proceed at source line 63 If you enter a STEP command at this point the debugger will proceed to source line 64 without stopping during the execution of the function call To step through the source code in the DEF function deffun you must use the STEP INTO command A STEP INTO com
617. xed Length String Descriptor Format A fixed length string descriptor consists of two longwords The first word of the first longword contains a value equal to the string s length The third byte contains 14 OK hexadecimal the OpenVMS code describing an ASCII character string The fourth byte contains 1 The second longword is a pointer containing the address of the string s first byte See Figure 17 11 For more information see the OpenVMS Calling Standard Figure 17 11 Fixed Length String Descriptor Format POINTER ZK 5178 GE Dynamic String Descriptor Format A dynamic string descriptor consists of two longwords The first word of the first longword contains a value equal to the string s length The third byte contains 14 OK hexadecimal the OpenVMS code describing an ASCII character string The fourth byte contains 2 The second longword is a pointer containing the address of the string s first character See Figure 17 12 For more information see the OpenVMS Calling Standard 17 10 Data Representation Figure 17 12 Dynamic String Descriptor Format POINTER ZK 5179 GE 17 5 Array Descriptors HP BASIC creates DSC K_CLASS_NCA a noncontiguous class array descriptor For more information see the OpenVMS Calling Standard 17 6 Decimal Scalar String Descriptor Packed Decimal String Descriptor A single descriptor form gives decimal size and scaling information for both scalar data and simple strings
618. y PRINT MAT mult array first array inv array MAT PRINT mult array PRINT D DET PRINT D Output 4 0 0 0 0 2 0 8 0 4 0 0 0 0 2 0 8 0 25 0 0 0 0 125 0 5 0 1 0 0 0 1 0 0 0 1 64 6 22 Arrays 6 7 2 3 DET Function The DET function returns the determinant of a matrix The DET function returns a floating point number that is the determinant of the last matrix inverted If you use the DET function before inverting a matrix the value of DET is zero Arrays 6 23 7 Data Definition This chapter briefly describes how to define program objects explicitly assign data types and allocate and use data storage 7 1 Declarative Statements You use declarative statements to define objects in a HP BASIC program Objects can be variables arrays constants and user defined functions within a program module They can also be routines variables and constants external to the program module Declarative statements always assign names to the objects declared and usually assign other attributes such as a data type to them Declarative statements can also be used to define user defined data types RECORD statements See Chapter 8 for more information about the RECORD statement You use declarative statements to assign data types to e Variables e Arrays e Named constants e Values returned by functions By declaring the objects used in your program you make the program easier to understand modify and debug
619. y If a continuation line begins with THEN or ELSE then no ampersand is necessary Similarly in a line following a THEN or an ELSE there is no ampersand IF A B THEN PRINT The two values are equal ELSE PRINT The two values are different END IF Several statements can be associated with a single program line If there are several statements on one line they must be separated by backslashes For example PRINT A PRINT V PRINT G Because all statements are on the same program line any reference to this program line refers to all three statements 4 2 Identifying Program Units You can delimit a main program compilation unit with the PROGRAM and END PROGRAM statements This allows you to identify a program with a name other than the file name The program name must not duplicate the name of a SUB FUNCTION or PICTURE subprogram For example PROGRAM Sort_out END PROGRAM If you include the PROGRAM statement in your program the name you specify becomes the module name of the compiled source This feature is useful when you use object libraries because the librarian stores modules by their module name rather than the file name Similarly module names are used by the OpenVMS Debugger and the OpenVMS Linker For more information about PROGRAM units see Chapter 12 4 4 BASIC Concepts and Elements 4 3 BASIC Character Set BASIC uses the full ASCII character set which includes the following e The letters A to
620. y locked on another channel or by another process Simultaneously your program has locked a record that the other user cannot access The deadlock cannot be resolved User Action Possible solutions include e Use the FREE statement to unlock all locked records e Use GET REGARDLESS if read access is sufficient DECERR DECIMAL error or overflow ERR 181 Explanation The result of a DECIMAL expression is greater than or requires more precision than can be contained in the variable User Action Reduce the magnitude of the expression or increase the allowed digits in the DECIMAL variable User Action Check program logic or trap the error in an error handler DEVHUNWRI Device hung or write locked ERR 14 Explanation The program attempted an operation to a hardware device that is not functioning properly or is protected against writing User Action Check the device on which the operation is performed Run Time Messages B 5 DEVINMET Device is an input metafile ERR 270 Explanation The operation cannot be performed on an input metafile device type 3 User Action Specify the device ID for a device other than an input metafile DEVNOTOPE Device is not open ERR 268 Explanation The device has not been identified in an OPEN FOR GRAPHICS statement User Action Specify the device ID number in an OPEN FOR GRAPHICS statement DEVOPEINC Device and operation are incompatible ERR 272 Explanation The operation y
621. y separating the variables with commas and enclosing them in parentheses All the string variables must be part of the associated map In the following example the primary key is made up of three string variables This key causes the records to be sorted in alphabetical order according to the user s last name first name and middle initial MAP Segkey STRING First_name 15 MI 1 Last_name 15 OPEN NAMES IND FOR OUTPUT AS FILE 13 amp ORGANIZATION INDEXED amp PRIMARY KEY Last_name First_name MI amp MAP Segkey Note that there are restrictions on the maximum record size allowed for various file and record formats See the OpenVMS Record Management Services Reference Manual for more information You can use logical names to assign a mnemonic name to all or part of a complete file specification including node device and directory The advantage in using logical names is that programs do not depend on literal file specifications You can define logical names from the following e From DCL command level with the ASSIGN or DEFINE command e From within a program with the SYS CRELMN system service BASIC supports any valid logical name as part of a file specification A logical name specifies a 1 to 255 character name to be associated with the specified device or file specification If the logical name specifies a device you must end the logical name with a colon The following example defines a logical name for a fil
622. y SYS SHARE If you want the image activator to access a shareable image outside SYS SHARE you must define a logical name to the shareable image before you execute the program Define the full file specification of the shareable image to the name of the shareable image as follows DEFINE MYSHR DISKSWORKDISK MYDIR MYSHR EXE This is a simple example of using shareable images For more information see the HP OpenVMS Linker Utility Manual and the Guide to Creating OpenVMS Modular Procedures 20 6 Libraries and Shareable Images 21 Using CDD Repository with BASIC This chapter explains how you can take advantage of CDD Repository capabilities For more detailed information about CDD Repository see Using CDD Repository on VMS Systems 21 1 Overview of CDD Repository CDD Repository is a common data dictionary tool that supports sharing of data definitions by OpenVMS programming languages and information architecture products Each language or product translates the generic definitions stored in CDD Repository language or product specific definitions that it can use BASIC supports CDD Repository features including dependency recording Dependency recording allows you to record or track which programs use CDD Repository data definitions Dependency recording helps evaluate the effort needed to change a record definition by identifying the modules that need to be modified recompiled or both To support dependency recording CD
623. y a string variable instead of a numeric variable SUBMAYNOT subscript may not be specified for entire array Explanation ERROR A CALL statement or external function reference passes an entire array as a parameter and contains a subscript expression for example A 3 User Action Remove the subscript expression You cannot specify any subscripts when passing an entire array as a parameter A 82 Compile Time Error Messages SUBOUTRAN subscript out of range for lt array name gt Explanation ERROR The program references an array element with constant subscript s outside the bounds of the array User Action Check program logic to make sure all subscripts are within the bounds of the array SUBRECCOM subscripting error in RECORD component Explanation ERROR The program contains a RECORD component reference with invalid subscripts for example A B 1 2 C where B has only one subscript or A B where A requires a subscript User Action Change the erroneous reference You must specify as many subscripts as were defined in the RECORD SUBWHINOT exit from SUB seen while not in SUB Explanation ERROR A program contains an EXIT SUB or SUBEXIT statement with no preceding SUB statement User Action If the program is a subprogram supply a SUB statement otherwise remove the EXIT SUB or SUBEXIT statement SUFFILNOT suffix not allowed on FILL after datatype keyword Explanation ERROR A FILL item defined with a
624. you opened the file without specifying ACCESS READ and the tape is not write locked that is if the plastic write ring is in place HP BASIC does the following e Writes file trailer labels and two end of file marks following the last record e Backspaces over the last end of file mark The tape is not rewound unless you specified RESTORE in your program Device Specific I O to Disks When performing device specific I O to disks you write and read data with PUT and GET statements The data must fit in 512 byte blocks and you must do your own blocking and deblocking with MAP REMAP or MOVE statements Note that when accessing disks with device specific I O operations you are performing logical I O Because of this you should be careful not to overwrite block number zero which is often the disk s boot block You must have LOG_ IO privileges to perform these operations The following sections describe device specific I O to disks 18 10 Advanced File Input and Output 18 2 3 1 18 2 3 2 18 2 3 3 18 2 3 4 Assigning and Mounting a Disk You must allocate a disk unit to your process before starting operations The following command line assigns disk DUA3 to your process ALLOCATE DUA3 When you perform I O directly to a disk you must mount the disk with the MOUNT command before accessing it For example MOUNT FOREIGN DUA3 You can then open the disk for input or output Opening a Disk File for Output To create an
625. you type a string the program prints the length of the string and explicitly reexecutes the loop DECLARE STRING User_string Read loop WHILE 1 1 LINPUT Please type a string User_string Program Control 9 15 IF User string THEN EXIT Read loop ELSE PRINT Length is LEN User string ITERATE Read loop END IF NEXT END 9 6 Executing Local Subroutines In HP BASIC a subroutine is a block of code accessed by a GOSUB or ON GOSUB statement It must be in the same program unit as the statement that calls it The RETURN statement in the subroutine returns control to the statement immediately following the GOSUB The first line of a subroutine can be any valid HP BASIC statement including a REM statement You do not have to transfer control to the first line of the subroutine Instead you can include several entry points into the same subroutine You can also reference subroutines by using a GOSUB or ON GOSUB statement to another subroutine Variables and data in a subroutine are global to the program unit in which the subroutine resides 9 6 1 GOSUB and RETURN Statements The GOSUB statement unconditionally transfers control to a line in a subroutine The last statement in a subroutine is a RETURN statement which returns control to the first statement after the calling GOSUB A subroutine can contain more than one RETURN statement so you can return control conditionally depending on a specified condition T
626. your programs For example the following statement causes a bell to sound on your terminal PRINT BEL You can also create your own predefined constants with the DECLARE CONSTANT statement BASIC Concepts and Elements 4 9 For more information about constants see Chapter 7 and the HP BASIC for OpenVMS Reference Manual 4 7 Variables A variable is a storage location that is referred to by a variable name Variable values can change during program execution Each named location can hold only one value at a time A variable name can have up to 31 characters The name must begin with a letter the remaining characters if any can be any combination of letters digits dollar signs underscores _ and periods Variables can be grouped in an orderly series such as a list or table under a single name called an array You refer to a single variable in an array by using one or more subscripts that specify the variable s position in the array See Section 4 7 5 for more information on arrays 4 7 1 Floating Point Variables A floating point variable is a named location that stores a floating point value The storage space required to hold the value depends on the variable s REAL subtype For example each SINGLE floating point variable requires 32 bits 4 bytes of storage while each DOUBLE floating point variable requires 64 bits 8 bytes of storage Note that if any integer value is assigned to a floating point vari
627. yword required in ANSI Explanation INFORMATION A program compiled with the ANSI_ STANDARD qualifier contains an assignment statement that omits the LET keyword User Action Supply a LET keyword LEXDIRSYN lexical directive syntax error Explanation ERROR A syntax error was detected in a lexical directive User Action Correct the syntax of the lexicial directive LEXIDEMUS lexical identifier must be declared before reference Explanation ERROR You reference a lexical identifier before you declare it User Action Declare the lexicial identifier before you reference it LINNOTALL line numbers not allowed use the EDIT command Explanation ERROR An EDIT command with a line number has been found in a program without line numbers User Action Use the EDIT command without specifying a line number to invoke a text editor LINNUMERR illegal line number Explanation ERROR The program contains a line number that is outside the valid range or is not a valid integer note that the percent sign suffix is not valid for line numbers User Action Specify only integer line numbers in the range 1 to 32 767 inclusive LINNUMINC line number may not appear in INCLUDE directive file Explanation ERROR The file specified in a INCLUDE compiler directive contains a line number User Action Remove the line number from the file A 52 Compile Time Error Messages LINNUMUND line number lt n gt undefined due to
628. zero User Action Correct the lower bound to be zero LOWRANVAL range lower value must be less than upper value Explanation ERROR In the RANGE clause the first value is greater than the second value User Action Change the range clause so that the first value is less than the second value A 54 Compile Time Error Messages LRSETNOT lt keyword gt is not allowed with MID Explanation ERROR The LSET and RSET keywords are not allowed with MID User Action Change the LSET or RSET keyword to LET MACNOTDEF macro is not defined Explanation ERROR The macro identifier used in this 7 UNDEFINE directive was not previously defined by a DEFINE directive User Action Verify that the identifier has been previously defined with the DEFINE directive Verify that the DEFINE and 2 UNDEFINE macro IDs match MAPDYNNOT MAP DYNAMIC lt map name gt may not be larger than 32 767 bytes Explanation ERROR A MAP DYNAMIC statement references a map that is greater than 32 767 bytes in size User Action Reduce the size of the map as defined in the MAP statement or MAP statements to 32 767 bytes or less MAPDYNREQ MAP DYNAMIC lt name gt requires corresponding static MAP Explanation ERROR The program contains a MAP DYNAMIC statement whose MAP name does not appear in a MAP statement User Action Provide a MAP with the same name as the MAP DYNAMIC name MAPNOTDEF MAP lt name gt used in OPEN not defined Explan

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