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Aztec C86 User Manual Release 1.05i June 83 Copyright (C) 1983

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1. double sqrt a errno 0 a sqrt double 2 if errno 0 if errno EDOM printf errno set to EDOM by sqrt n else Copyright 1983 c by Manx Software Systems Page VII 24 Aztec C86 LIBRARY FUNCTIONS printf invalid errno d returned by sqrt n Table 2 1 1 Error codes returned in ERRNO by sqrt Code sqrt x Meaning EDOM 0 0 x lt 0 0 log double log x double x log is a function of one argument which returns the natural logarithm of the argument as its value as a double precision floating point number The argument which is passed to log must be a double precision floating point number and must be greater than zero If log detects an error it sets a code in the global variable ERRNO and returns an arbitrary value otherwise it returns to the caller without modifying ERRNO Table 2 2 1 lists the symbolic values which log may set in ERRNO the associated values returned by log and the meaning Table 2 2 1 Error codes returned in ERRNO by log Code log x Meaning EDOM HUGE x lt 0 0 loglO double logl0 x double x loglO is a function of one argument which returns as its value the base 10 logarithm of the argument The type of the returned value is double The argument must be greater than zero and must be of type double If loglO detects an error it sets a code in the global Copyright 1983 c by Manx Software Systems Page VII 25 Aztec C86 LIBRARY F
2. gt 6 7465e9 Copyright 1983 c by Manx Software Systems Page VII 27 Aztec C86 LIBRARY FUNCTIONS cos double cos x double x cos is a function of one argument which when called returns as its value the cosine of the argument The returned value is of type double The argument is in radians and its absolute value must be less than 6 7465e9 The type of the argument is double If cos can t perform the computation it returns an arbitrary value and sets a code in the global integer ERRNO otherwise it returns the computed value without modifying the associated value returned by cos and the meaning Table 2 1 1 Error codes returned in ERRNO by cos Code cos x Meaning ERANGE 0 0 labs x gt 6 7465 e9 tan double tan x double x tan is a function of one argument which when called returns as its value the tangent of the argument The type of the value returned is double The argument is in radians and its absolute value must be less than 6 7465e9 The type of the argument is double If tan can t perform the computation it returns an arbitrary value and sets a code in the global integer ERRNO otherwise it returns the computed value without modifying ERRNO Table 2 8 1 lists the codes which tan may set in ERRNO the associated value returned by tan and the meaning Table 2 1 1 Error codes returned in ERRNO by tan ERANGE 0 0 labs x gt 6 7465e9 Copyright 1983 c by Manx Software System
3. exmpl o subl o sub2 0 sub3 o math lib libc lib 6 S option This option is used to explicitly select the amount of extra space the linker includes in the data segment above the linked data The size defaults to 4096 bytes The size in hex immediately follows the intervening spaces S option with no Copyright 1983 c by Manx Software Systems Page V 3 AZTEC C86 LINKER For example to link exmpl o and give it 100H extra bytes above the data enter LN exmpl o S100 II Programmer s Information The LN linker can create two physical segments for a program a code segment and a data segment Each physical segment can be up to 64 K bytes long Logical segments from the assembler ie those defined by the segment and ends directives in an assembly language program are grouped into physical segments as follows logical segments whose combinability type is common are included in the physical data segment Segments whose class name is code are included in the physical code segment All other segments are included in the physical data segment Copyright 1983 c by Manx Software Systems Page V 4 Aztec C86 LIBUTIL LIBRARY UTILITY LIBRARY MAINTENANCE LIBUTIL A SUMMARY The LIBUTIL LIBrary UTILity is used in order to l create a library 2 append modules a 3 produce an index list t 4 extract modules x 5 replace modules r 6 create a library using an extended command line l LI
4. without prior written permission of Manx Software Systems Box 55 Shrewsbury N J 07701 DISCLAIMER Manx Software Systems makes no representations or warranties with respect to the contents hereof and specifically disclaims any implied warranties of merchantability or fitness for any particular purpose Manx Software Systems reserves the right to revise this publication and to make changes from time to time in copyright c 1983 by Manx Software Systems Aztec C86 License the content hereof without obligation of Manx Software Systems to notify any person of such revision or changes TRADEMARKS Aztec C86 Manx AS86 and Manx LN are trademarks of Manx Software Systems CPM86 and SID86 are trademarks of Digital Research MSDOS MASM and LINK are trademarks of Microsoft UNIX is a trademark of Bell Laboratories copyright c 1983 by Manx Software Systems Aztec C86 CONTENTS SECTION Installation us A aaa I Overview EEE AAA ee eee ee CET Aztec C06 COMDL Ler E das LET MANX AS86 Relocating Assemblel oooooooooooooooooooroooooo IV MANX UN Te SIC yo sow ee Se ete a we eee tes wre Sgr th aciee S wk Soe e a elas V MANX LIBUTIE Library Utility nas iras aa VIC Library PUNRCELONS iise e es ii A a as ra MEL Error Codes and Error Processing o ooooooooooooooooooo VIII I O Redirection and Buffered I O ooooooooooooooonooono o IX Unbuf erea MO aa Assembly Language Support ooooooooooroooooooonnoooo ro o XI Data FormatS ooo
5. x tangent of x tanh x hyperbolic tangent function B DETAILED LISTING OF LIBRARY FUNCTIONS Explanation of Format of Library Descriptions The following is a sample library function description Each of its parts is numbered and explained in the paragraphs below All the library functions found in this section of the manual follow this format 1 fseek 2 int 3 fseek 4 stream pos mode 5 FILE stream 6 int pos mode 1 fseek The word located in the left margin is the name of the function to be described The functions are listed in alphabetical order according to category 2 int This is a definition of the type of value returned Here it is an integer Other types could be longs characters doubles pointers etc 3 fseek This again is the name of the function 4 stream pos mode This is a prototype of the parameter list In this example stream is a pointer to a structure of type FILE The parameters of pos and mode are integers 5 FILE stream This defines the stream parameter as type FILE All parameters must be defined as they are in the function definition G6 int pos mode This defines defines pos and mode as integers NOTES l FILE is defined in file libc h or stdio h Standard I O functions Copyright 1983 c by Manx Software Systems Page VII 3 Aztec C86 LIBRARY FUNCTIONS These functions provide a uniform I O interface for all programs written in Aztec C86 regardless of the op
6. and each of the dash options are separated by spaces and can be entered in any order All dash options begin with the dash character and are immediately followed by a letter which defines the option After that the symtax for the various dash options can differ In some cases that s all there is to the option In others the letter defining the option is followed by a number which gives a value relating to the option In another case the next field following the option is a file name The various dash options are described below A Source File The source file name can either specify the disk drive containing the file or not If it s not specified the assembler assumes the file is on the default drive B Object File AS86 writes the object code to a file If the file doesn t exist A86 will create it if it does exist AS86 will erase it and create a new one By default the name of the object file is derived from the source file is given extent o and is placed on the same drive as the source file For example to assemble b subl asm and place the object code in b subl o enter AS86 b subl asm The default name for the object file can be overriden by specifying the O0 dash option when the assembler is invoked In this case the object file name is in the field following the O option For example to assemble b subl asm and place the object in a out o enter AS86 b subl asm O a out o There must be spaces
7. be truncated so that nothing is in it and then will be opened The truncation is performed by erasing the file if it exists then creating it It s not an error to truncate a file which doesn t previously exist If both O CREAT and O TRUNC are specified open proceeds as if only O TRUNC was specified If open doesn t detect an error it returns as its value an integer called a file descriptor which must be included in the list of parameters which are passed to the other unbuffered i o functions when performing i o operations on the file The file descriptor is different from the file pointer which is used for buffered i o If open does detect an error it returns as its value l and sets a code in the global integer errno which defines the error The symbolic values which open may set in errno and their meanings are errno value meaning EMFILE maximum number of open devices and files exceeded 11 s the limit EACCES invalid access requested ENFILE maximum number of open files exceeded EEXIST file already exists when O CREAT and O EXCL are both specified ENOENT unable to open file The file errno h defines the integer values of the symbolic values If open doesn t detect an error errno isn t modified Examples 1 To open the system console for read access fd open con O RDONLY 2 To open the line printer for write access fd open 1st O WRONLY 3 To open the file b sample ext for read only access
8. is unpacked into the proper places The _fcb structure is defined in io c The structure need not be used Copyright 1983 c by Manx Software Systems Page VII 23 Aztec C86 LIBRARY FUNCTIONS however fcbptr must point to an area at least 36 bytes long settop char settop size unsigned size The current top of available memory is moved up by size bytes and the old value of the top is returned If the new top is within 512 bytes of the stack pointer NULL will be returned 6 Math and Scientific Routines sqrt double sqrt x double x sqrt is a function of one argument which returns as its value the square root of the argument The type of the returned value is double The argument which is passed to sqrt must be of type double and must be greater than or equal to zero If sqrt detects an error it sets a code in the global integer variable ERRNO and returns an arbitrary value to the caller If sqrt doesn t detect an error it returns to the caller without modifying ERRNO Table 2 1 1 lists the symbolic values which sqrt may set in ERRNO and their meanings The file MATH H which can be included in a user s module declares ERRNO to be a global integer and defines the numeric value associated with each symbolic value EXAMPLE In the following program sqrt computes the square root of 2 If the computation returns a non zero value in ERRNO the program prints an error message include libc h include errno h main
9. library is not copied If after LIBUTIL has processed all modules in the subject library in this manner any files in the input file list remain which haven t been copied to the new library LIBUTIL then copies the contents of these files to the new library Finally LIBUTIL erases the original subject library and renames the new library giving it the name of the subject library file The user can give LIBUTIL the name of the subject library either explicitly or implicitly To explicitly define it the user includes the character o in a dash parameter the parameter immediately following this dash parameter must then be the name of the subject library file To implicitly define it the user simply doesn t include the o character in adash parameter LIBUTIL then assumes that the name of the subject library file is libc 1lib All parameters which follow the dash parameters and the subject file name are names of input files The drive identifier and or the extent of these names can be optionally ommitted If the drive identifier is omitted LIBUTIL assumes the file is on the default drive If the extent is omitted LIBUTIL assumes the extent is ext LIBUTIL can be told to read additional input file names from one or more lines on the console device by including the character in place of one of the input file names on the LIBUTIL command line In this case LIBUTIL will read input file names from the console until another is rea
10. meaning Copyright 1983 c by Manx Software Systems Page VII 29 Aztec C86 LIBRARY FUNCTIONS Table 2 1 1 Error codes returned in ERRNO by asin acos double acos x double x acos is a function of one argument which when called returns as its value the arcosine of the argument The returned value is of type double The absolute value of the argument must be less than or equal to 1 0 It must be of type double If acos can g perform the computation it returns an arbitrary value and sets a code in the global integer ERRNO otherwise it returns the computed value without modifying ERRNO Table 2 11 1 lists the symbolic codes which acos may set in ERRNO the associated value returned by acos and the meaning Table 2 1 1 Error codes returned in ERRNO by acos atan double atan x double x atan is a function of one argument which when called returns as its value the arctangent of the argument The returned value is of type double The argument can be any real value and must be of type double Unlike many of the other math functions atan never returns code in ERRNO Copyright 1983 c by Manx Software Systems Page VII 30 Aztec C86 LIBRARY FUNCTIONS atan2 double atan2 y x double y x atan2 is a function of two arguments say x and y which when called returns as its value the arctangent of y x in radians y is the first argument and x is the second The returned value is of type double The ar
11. suppose that we are back at the point at which we have the original example lib containing modules subl sub2 and sub3 and that we have the file newsub o After entering the following commands rename sub4 o newsub o LIBUTIL oa example lib sub4 example lib will contain modules named subl sub2 sub3 sub4 2 Let example lib contain the modules subl sub2 and sub3 and let newlib lib contain the modules newsubl newsub2 and newsub3 We can tell LIBUTIL to append the modules in newlib lib to example lib by entering any of the following lines LIBUTIL oa example lib newlib lib LIBUTIL a o example lib newlib lib LIBUTIL o example lib a newlib lib After LIBUTIL is done there will be a new example lib and it will contain the following modules in the specified order subl sub2 sub3 newsubl newsub2 newsub3 To illustrate another point let s rerun LIBUTIL again with the comand specified above starting with the original example lib containing subl sub2 and sub3 and with the library file newlib lib containing the modules sub3 newsubl subl and newsub2 After LIBUTIL completes there will be a new example lib and it will contain the following modules in the specified order subl sub2 sub3 sub3 newsubl subl newsub2 The first subl module in the new example lib will be that from Copyright c 1983 by Manx Software Systems Page VI 7 Aztec C86 LIBUTIL LIBRARY UTILITY the original example lib and the second wil
12. symbol or macro being defined and string2 is the value of the symbol the brackets surrounding string2 mean that string2 is optional If string2 isn t entered the value of the symbol defaults to 1 No spaces are allowed between the first character of stringl and the last character of string2 For example to compile exmpl c and to define the symbol DEBUG to the program from the command line and give it a value of 1 enter l C86 exmpl c DDEBUG To compile exmpl c and define the macro x y 10 y enter C86 exmpl c Dx y 10 y If the compiler is running under CP M 86 all references within the program being compiled to a command line defined symbol or macro must be in upper case since CP M 86 translates the command line to upper case before activating C86 If the compiler is running under PCDOS or MSDOS a program being compiled to a command line defined symbol or macro must refer to it exactly as entered on the command line since PCDOS and MSDOS don t translate the command line to upper Case on PCDOS and MSDOS the strings can be either upper or lower case the program being compiled must refer to the symbol just as Copyright 1983 c by Manx Software Systems Page III 5 AZTEC C86 COMPILER it s entered Copyright 1983 c by Manx Software Systems Page III 6 AZTEC C86 COMPILER C Compiler Error Messages ERROR NUMBER EXPLANATION 1 bad digit in octal constant 2 string space exausted see COMPILER Z option 3 u
13. the linker The dash options are described below The linker can link together any number of object files and search any number of libraries Object files are included in the order encountered in the command tail and libraries are searched sequentially in the order of specification When LN includes a module from a library which satisfies unresolved references new unresolved references may be created due to the external symbols referenced by the library module The linker will not go back through libraries which have already been searched or through the part of the current library which has already been searched to try and find modules which contain symbols which satisfy the unresolved references It will press on When LN is used with MSDOS or PCDOS the resultant executable program is written to a file whose name is derived from the first object file name in the command tail by changing the extent to sexe This default assumption can be overriden using the o option described below When LN is used with CPM86 the resultant executable program is written to the file whose name is derived from the first object file in the command tail by changing the extent to cmd This default assumption can be overriden using the O option Supplied with Aztec C86 are the object libraries libc lib and math lib In most cases libc lib must be specified when linking a program Math lib must be included when linking a program which performs flo
14. to one machine and explicitly limits duplication of the products to no more than two copies whose sole purpose will be for backup Any uses of these products that might lead to the creation of or distribution of unauthorized copies of these products will be a breach of the licensing agreement and Manx Software Systems will excercise its right to reclaim the original and any and all copies derived in whole or in part from first or later generations and to pursue any appropriate legal actions Software that is developed with Aztec C86 Manx AS86 or Manx LN can be run on machines that are not licensed for these products as long as no part of the Aztec C86 software libraries supporting files or documentation is distributed with or required by the software In the latter case a licensed copy of the appropriate Aztec C software is required for each machine utilizing the software There is no licensing required for executable modules that include library routines The only restriction is that neither the source the libraries themselves or the relocatable object of the library routines can be distributed COPYRIGHT Copyright C 1981 1982 1983 by Manx Software Systems All rights reserved No part of this publication may be reproduced transmitted transcribed stored in a retrieval system or translated into any language or computer language in any form or by any means electronic mechanical magnetic optical chemical manual or otherwise
15. too long illegal encountered macro table full see COMPILER X option output file error reference of member of undefined structure function body must be compound statement undefined label inappropriate arguments illegal argument name expected comma invalid else syntax error missing semicolon bad goto syntax statement syntax statement syntax statement syntax case value must be integer constant missing colon on case too many cases in switch see COMPILER Y OPTION case outside of switch missing colon duplicate default default outside of switch break continue error illegal character too many nested includes illegal character not an argument null dimension invalid character constant not a structure invalid storage class symbol redeclared illegal use of floating point type illegal type conversion illegal expression type for switch bad argument to define no argument list missing arg bad arg not enough args conversion not found in code table Copyright 1983 c by Manx Software Systems Page III 8 Aztec C86 ASSEMBLER AS86 the MANX 8086 relocating assembler I OPERATING INSTRUCTIONS AS86 is activated by entering on the command line AS86 lt command tail gt where lt command tail gt specifies the source file to be assembled and the dash options that is the optional flags and parameters which override default assembler assumptions In the command tail the source file name
16. 6 the default chaining of the assembler to the compiler can be overriden using the A option In this case Copyright 1983 c by Manx Software Systems Page III 1 AZTEC C86 COMPILER the compiler will stop after compilation and won t invoke the assembler The assembler source by default will be sent to the file whose name is derived from the C source file name by changing the extent to a86 This default can be overriden using the 0 option B Compiler options Under MSDOS or PCDOS the dash option specifiers must be entered in upper case With CP M 86 they can be entered in either upper or lower case since CP M 86 translates the command tail to upper case l 0 option The 0 option allows the user to explicitly select the output file of the compiler or the assembler as described above The syntax is O lt output filename gt where there is a space between 0 and lt filename gt For example under PCDOS to compile exmpl c on the default drive and send the output to exmpl asm on the default drive just enter C86 exmpl c still under PCDOS to compile exmpl c and send the assembly language output to b exmpl asm enter C86 exmpl c O b exmpl asm or C86 O b exmpl asm exmpl c If you re running with CP M 86 to compile and assemble exmpl c which is on the default drive and send the object code to exmpl o on the default drive enter C86 exmpl c Still under CP M 86 to compile and assemble exmpl c and send t
17. Aztec C86 User Manual Release 1 051 June 83 Copyright C 1983 by Manx Software Systems All Rights Reserved Worldwide Distributed by Manx Software Systems P O Box 55 Shrewsbury N J 07701 201 780 4004 Aztec C86 Introduction INTRODUCTION Welcome to the growing number of Aztec C86 users This manual will describe the use of the various components of the Aztec C86 system 1 1 Origin of Cc Dennis Ritchie originally designed C for the UNIX project at Bell Telephone Laboratories All of the UNIX Operating system its utilities and application programs are written in C 1 2 Standard Reference Manual for C The standard reference for the C language is Brian W Kernighan and Dennis M Ritchie The C Programming Language Prentice Hall Inc 1978 Englewood Cliffs N J The above text besides providing the standard definition and reference for the C language is an excellent tutorial Aztec C86 can be conveniently used in conjunction with the K R text for learning the Cc language Aztec C86 is a complete implementation of the K R standard C The K R book is an essential part of the Aztec C86 documentation Most questions regarding the C language and many questions on the run time library package will only be answered in the K amp R text 1 3 Basic Components of the Aztec C86 System The Aztec C86 system consists of a comprehensive set of tools for producing software using the C programming
18. BUTIL o example lib x o X O USE to create a library FUNCTION the following creates a private library example lib containing modules subl o and sub2 0 gt LIBUTIL o example lib subl o sub2 o 2 LIBUTIL option a USE to append to a library FUNCTION the following appends exmpl o to the example lib gt LIBUTIL o example lib a exmpl o this function can be used to append any number of o files to the library For example the following appends exmpl o and smpl o to the example lib gt LIBUTIL 0o example lib a exmpl o smpl o NB If a large number of files need to be appended to a library it is advantageous to use the SUBMIT option see item 7 3 LIBUTIL option t USE to produce an index listing of modules in a given library FUNCTION the following displays a listing of all Copyright c 1983 by Manx Software Systems Page VI 1 Aztec C86 gt LIBUTIL 4 LIBUTIL option x USE FUNCTION gt LIBUTIL gt LIBUTIL 5 LIBUTIL option r USE FUNCTION gt LIBUTIL LIBUTIL LIBRARY UTILITY modules in a particular library example lib O example lib t NB this function will allow only one library to be listed at a time a copies a particular library module into a relocatable object file b copies a complete library into relocatable object files a the following copies library module exmpl into a relocatable object file O example lib x exmpl b the following copies a complete libra
19. For computation characters are promoted to signed integers 2 pointer Pointers are two bytes 16 bits long The internal representation of the address FOAB stored in location 100 would be location contents in hex format 100 AB 101 FO 3 int short Integers are two bytes long A negative value is stored in two s compliment format A 2 stored at location 100 would look like location contents in hex format 100 FE 101 FF 4 long Long integers occupy four bytes Negative values are stored in two s complement representation Longs are stored sequentially with the least significant byte stored at the lowest memory addres and the most significant byte at the highest memory address 5 float and double Floating point numbers are stored as 32 bits doubles are stored as 64 bits They are in standard 8087 format Copyright C 1983 by Manx Software Systems Page XII 1 Aztec C86 FLOATING POINT SUPPORT When a floating point exception occurs in addition to returning an indicator in flterr the floating point support routines will log an error message to the console The error message logged by the support routines define the type of error that has occurred overflow underflow or division by zero and the address in hex of the instruction in the user s program which follows the call to the support routines Following the error message logging the floating point support routines return to the user s program which calle
20. L proceeds by first creating the library in a new file having a temporary name if the creation is successful LIBUTIL then erases the file named lt output library file gt if it exists and renames the file containing the newly created library to lt output library file gt lt input file list gt defines the files containing the modules which are to be placed in the library An input file can be either 1 a file created by the Manx assembler AS in which case it contains a single relocatable object module or it can be 2 another library which was created by LIBUTIL In either case the input files are not modified by LIBUTIL LIBUTIL just copies the modules in the input files to the output library An lt input file list gt is one or more names separated by spaces A name can be one of the following 1 a complete CP M file name eg b subl o 2 a CP M file name which doesn t specify the disk drive on which the file resides eg subl o in this case LIBUTIL assumes the file is on the default disk drive 3 a name which doesn t specify an extension in this case LIBUTIL assumes the file name is lt name gt 0 For example if the name is subl LIBUTIL assumes the file name is subl o and is on the default disk drive If the name is b subl LIBUTIL assumes the file name is b subl o When an input file contains a single relocatable object module the name by which the module is known in the library is the filename less the disk driv
21. UNCTIONS integer ERRNO and returns an arbitrary value to the caller otherwise it returns to the caller without modifying ERRNO Table 2 3 1 lists the symbolic values which logl0 may set in ERRNO the associated value returned by logl0 and the meaning Table 2 1 1 Error codes returned in ERRNO by logl0 m m n O SED SS mo CO GUY O GOED CORD Gee E ER aua aun ann O A cee ene OD O OO cee mme eet LU ORR nmo mao ome ee SEED e Ge oo ao A O UU UA eed UN SD COL A A A AO UI OED mme OO mem ae LU SEO mmo CO Cs a Gee omeo mae me me meo mmo aue om Oe exp double exp x double x a exp is a function of one argument which returns as its value e argument The type of the returned value is double The argument must be greater than 354 8 and less than 349 3 it must be of type double If exp is unable to perform the computation it sets a code in the global integer ERRNO and returns an arbitrary value otherwise it returns the computed value without modifying ERRNO Table 2 4 1 lists the symbolic values that exp may set in ERRNO the associated value of exp and the meaning Table 2 1 1 Error codes returned in ERRNO by exp ERANGE 0 0 x lt 354 8 pow double pow x y double x y pow is a function of two arguments for example x andy which when called returns as its value x to the y th power x y in FORTRAN notation x is the first argument to pow and y the second The value returned is of type double Copyri
22. acter 0 2 To set the current position to the character following the last character in the file lseek fd OL 2 lseek returns as its value the current position of the end of the file plus l 3 To set the current position 5 characters before the present current position lseek fd 5L 1 4 To set the current position 5 characters after the present current position lseek fd 5L 1 open name rwmode char name The function open prepares a device or file for unbuffered i o and returns as its value an integer which must be included in the list of parameters for the i o function calls which refer to this device or file The name parameter is a pointer to a character string which is the name of the device or file which is to be opened When using PCDOS or MSDOS the system console is named Copyright 1983 c by Manx Software Systems Page VII 13 Aztec C86 LIBRARY FUNCTIONS con Other devices have their standard MSDOS PCDOS names When using CPM86 the names of the devices which can be opened are device name device con system console lst or prn line printer pun punch device rdr reader device The names Can be either upper or lower case When a disk file is to be opened the name string can be a complete name for example b sample ext The drive identifier and the colon character can be omitted in this case the file is assumed to be on the default drive The extent and preceeding period can
23. also be omitted if the file doesn t have an extent field The mode parameter specifies the type of access to the device or file which is desired and optionally for a disk file specifies other functions which open should perform The mode values are mode value meaning O _RDONLY read only O WRONLY write only O_RDWR read and write O_CREAT create file then open it O TRUNC truncate file then open it O_EXCL if O EXCL and O CREAT are both set open will fail if the file exists The integer values associated with the symbolic values for mode are defined in the file fentl h which can be included in a user s program To guarantee UNIX compatibility a program should set the mode parameter using these symbolic names The calling program must specify the type of access desired by including exactly one of O_RDONLY O_WRONLY or O_RDWR in the mode parameter The other values for mode are optional and if specified are or ed into one of the type of access values If only the O CREAT option is specified the file will be created if it doesn t exist and then opened If the file does exist it is simply opened If the O _CREAT and O_EXCL options are both specified and if it didn t previously exist it will be created and then opened If it did previously exist the open will fail Copyright 1983 c by Manx Software Systems Page VII 14 Aztec C86 LIBRARY FUNCTIONS If the O TRUNC option is specified the file will
24. ample subl o libl lib sub2 0 where subl o and sub2 0 each contain a single relocatable object module and libl lib is a library containing modules sub3 sub4 and sub5 in that order then the created library would contain modules in the following order subl sub3 sub4 sub5 sub2 If there are additional lines of input file lists then modules are placed in the created library in the following order first the modules in the files preceeding the period flag are placed in the created library as defined above second the modules in the additional input file lists are placed in the created library third the modules in the files succeeding the period flag are placed in the created library For example suppose LIBUTIL is invoked with the following sequence LIBUTIL o newlib lib subl o sub2 0 sub3 o sub4 o sub5 o sub6 0 If each of the input files contains a single relocatable object module then the created library would contain the following modules in the specified order subl sub3 sub4 sub5 sub6 sub2 Copyright c 1983 by Manx Software Systems Page VI 4 Aztec C86 LIBUTIL LIBRARY UTILITY Listing the modules in a library To have LIBUTIL produce a listing of the modules in a library LIBUTIL must be invoked with a dash parameter which contains the character t A dash parameter is simply a parameter which has a dash as its first character LIBUTIL lists only the modules in the library not the functions Th
25. and linker C86 M exmpl c MASM exmpl LINK exmpl 1ibcms This procedure is depicted in figure 2 2 The first command activates the Aztec compiler C86 which compiles the C program in exmpl c and writes the resultant assembly language source to the file exmpl asnm The second command activates the MSDOS PCDOS assembler MASM which assembles the code in exmpl asm and writes the resulting object code to the file exmpl o The third command activates the MSDOS PCDOS linker LINK which links exmpl o getting any needed modules form the object library libcms lib and writes the executable program to the file exmpl exe If the exmpl c program performed floating point operations the command to link it would be LINK exmpl mathms lib libcms lib Copyright 1983 c by Manx Software Systems Page II 3 AZTEC C86 OVERVIEW Figure 2 2 depicts the basic steps for producing a binary image of a C program when using MSDOS or PCDOS and their assembler and linker It also indicates the path for producing and using run time subroutine libraries The process depicted is fairly basic Ponen EDITOR Eon nino E l source file E e e e Aztec C86 compiler poe ee ASM source file Ho om 3 MSDOS Assembler A A eee f sop A object file gt MSDOS LIB librarian En o TEESE Ho o subroutine Y 4 MSDOS Link Editor lt l
26. apter on unbuffered i o 3 String Manipulation These functions allow manipulation of C style strings as described in The C Programming Language by Kernighan and Ritchie atof Copyright 1983 c by Manx Software Systems Page VII 18 Aztec C86 LIBRARY FUNCTIONS atoi atol ftoa double atof cp char cp ASCII to float conversion routine int atoi cp char cp Converts ASCII string of decimal digits into an integer Atoi will stop as soon as it encounters a non digit in the string long atol cp char cp ASCII to long conversion routine int ftoa m cp precision type double m char cp int precision int type convert from float double format to character format The value of m is converted to ans ASCII string and assigned to c The precision operand specifies the number of digits to the right of the decimal point Type can be O for E format 1 for F format index char index cp c char cp C Searches string cp for the letter specified by parameter c If the letter is found then the function returns a pointer to its position Othersise a O is returned rindex Copyright 1983 c by Manx Software Systems Page VII 19 Aztec C86 LIBRARY FUNCTIONS char rindex cp c Functions the same as index but the scan begins from the end Of the string and moves towards the beginning sscanf int sscanf string control argl arg2 char string char control Formats string accor
27. at argptr form argl arg2 LIBRARY FUNCTIONS writes from buffer to fd BUFSIZE bytes ASCII to floating ASCII to integer converts ASCII to long converts floating point to ASCII returns cp from beginning of string returns cp from end of string compares strli with str2 string copy routine returns length of string compares srtl to str2 at most max string copy at most max characters converts converts allocate space moves length bytes from src to dest initializes area to value stop program formats data using routine function checks for digits 0 9 checks for lower case checks for upper case places string format data in buffer converts to lower case converts to upper case Operating System Interface bc de n name fcbptr size calls bdos returns to the operating system initializes file control blocks bumps top of program memory Math and Scientific Routines we ee ee eee ee ee R Nu ee eee w A o TU a A A AAA Ke N at SS AAA SR E a A Du S 1983 c by Manx Software Systems inverse cosine of x arcos x inverse sine of x arcsin x inverse tangent of arctan x arctangent of x divided by y cosine of x hyperbolic cosine cotangent of x exponential function of x natural log of x logarithm basi of x raise x to the y th power random number generator Sine of x hyperbolic sine function Page VII 2 Aztec C86 LIBRARY FUNCTIONS sqrt x returns the square root of x tan
28. ating point operations and must be specified in the LN command tail before libc lib To link a simple program which doesn t perform floating point and whose object code is in the file exmpl o enter Copyright 1983 c by Manx Software Systems Page V 1 AZTEC C86 LINKER LN exmpl o libc lib The linker will place the executable code in the file exmpl exe when running with PCDOS or MSDOS and in exmpl cmd when running with CP M 86 If the above program performed floating point operations it would be linked by entering LN exmpl o math lib libc lib If the exmpl program called functions whose object code is in subl o sub2 0 and sub3 o it could be linked by entering LN exmpl o subl o sub2 o sub3 o math lib libc lib If subl sub2 and sub3 are commonly used functions they could be put in an object file library which we ll call sub2 1ib using the Manx program LIBUTIL then exmpl could be linked by entering LN exmpl o subs lib math lib libc lib Dash Options l O option This option specifies the name of the file to which the executable program generated by LN is sent If not specified LN generates the output file name from the name of the first object module in the command tail as described above For example to link exmpl o and send the output to b exmpl exe enter LN O b exmpl exe exmpl o libc lib 2 T option This option causes the linker to generate a symbol table which can be read by the Digital Res
29. between O and the object file name Copyright 1983 c by Manx Software Systems Page IV 1 Aztec C86 ASSEMBLER C Listing File AS86 does not currently generate a listing D Dash Options l S option Symbol table size By default the symbol table can have 500 entries To select another value use the S dash option where the desired size immediately follows the S with no intervening spaces For example AS86 subl asm S1000 assembles subl asm using a symbol table having 1000 entries 2 Z2 option String space size By default string space the area where symbol names and other character strings are stored is 200 bytes long To select another size use the 2 option where the desired size immediately follows the Z with no intervening spaces For example AS86 Z1500 subl asm assembles subl asm using a 1500 byte string space 3 C option Codemacro table size By default the codemacro table can have 50 entries Use the C dash option to select another value where the desired size immediately follows C with no intervening spaces For example AS86 C100 subl asm assembles subl asm using a codemacro table having 100 entries 4 v option Verbose option Entering v will cause the assembler to list statistics after it finishes It will list the number of symbol table entries used the number of bytes of string space used and the number of entries in the codemacro table that were used II Program
30. brary utility LIBUTIL allows a user to change the contents of the standard Manx supplied run time library or to create private run time library The run time library is included in the standard package in source form in Manx library format and in MICROSOFT library format 1 5 System Requirements Aztec C86 runs on any PCDOS MSDOS or CP M 86 system with at least 128K of memory and two disk drives There are no special terminal requirements for Aztec C86 other than the ability to produce upper and lower case and the special characters O eS Se A af E ae ee O 1 6 Cross Compilers A UNIX PDP11 cross compiler is available for Aztec C86 The output of the compiler assembler or linker can be downloaded to the target machine 1 7 Portability Code written for Aztec C86 can be compiled with Aztec C II the Manx 8080 and Z80 C compiler and with Aztec C65 the Apple DOS 3 3 C compiler Copyright c 1983 by Manx Software Systems Page 1 2 Aztec C86 License SOFTWARE LICENSE Aztec C86 Manx AS86 and Manx LN are licensed software products Manx Software Systems reserves all distribution rights to these products Use of these products is prohibited without a valid license agreement The license agreement is provided with each package Before using any of these products the license agreement must be signed and mailed to Manx Software Systems P O Box 55 Shrewsbury N J 07701 The license agreement limits use of these products
31. by calling the function fopen fclose releases the control blocks and buffers which it had allocated to the device or file thus allowing them to be used when other devices or files are opened for buffered i o Also when a disk file is being closed fclose writes the internally buffered information if any to the file If the close operation is successful fclose returns a non negative integer as its value If it isn t successful fclose returns 1 as its value and sets an error code in the global integer errno If the close was successful errno is not modified feof feof stream FILE stream Returns O if stream is not at EOF otherwise it returns l ferror ferror stream FILE stream Returns O if no error has occurred on the stream otherwise it returns 1l fgets char fgets buffer max stream char buffer int max FILE stream The function fgets reads characters from a device or file which has been previously opened for buffered i o by a call to fopen into the caller s buffer The operation continues until either 1 a newline character n is read or 2 the maximum number of characters specified by the caller have been transferred If the newline character is read it will appear in the caller s buffer If the read operation is successful fgets returns as its value a pointer to the start of the caller s buffer Otherwise it returns the pointer NULL and sets a code in the global int
32. ch were input by the user the read function places a carriage return line feed sequence Copyright 1983 c by Manx Software Systems PAGE X 2 Aztec C86 Unbuffered 1 0 The read function returns characters to the calling program from the internal buffer If there are characters in the buffer which haven t yet been passed to the caller the read function transfers some to the caller s buffer with the number transfered being either the number requested by the caller or the number remaining in the internal buffer from the last actual console read operation which haven t been passed to the caller If the internal buffer is empty when the caller makes a request of the read function the read function performs an actual console read operation to refill the internal buffer as described above and then transfers characters from it to the caller s buffer The read function returns to the caller as its value the number of characters placed in the caller s buffer or zero if the operator typed ctl z in response to a console read operation by the read function or 1 if an error occurred If an error occurred the read function also places a code in the global integer errno which defines the error If no error occurred read returns without modifying errno The only symbolic value which read may place in errno is EBADF in response to an invalid file descriptor from the caller The integer value of EBADF is defined in the file errno h which may be inc
33. cluding the codemacros for them in your programs 8 To include a file in the assembly of a program being assembled enter INCLUDE lt filename gt in the program being assembled where lt filename gt is the name of the file to be included Included files can be nested five deep 9 AS86 supports conditional assembly The statements IF lt condition gt lt block gt ENDIF will result in the assembly language statements in lt block gt being assembled if lt condition gt has a non zero value If lt condition gt has the value zero the lt block gt statements will be ignored The statements IF lt condition gt lt true block gt ELSE lt false block gt ENDIF will cause lt true block gt to be assembled if lt condition gt is non zero and lt false block gt otherwise The IF constructs can be nested Copyright 1983 c by Manx Software Systems Page IV 4 AZTEC C86 LINKER LINKER I Operating Instructions The Manx link editor LN combines object files produced by the Manx AS86 assembler copies needed modules from object libraries which have been created using LIBUTIL the Manx object file librarian and produces an executable file To activate the linker enter LN lt command tail gt where lt command tail gt is a list of file names and dash options The command tail fields that is file names and dash options are separated by spaces A dash option is used to override a default assumption by
34. d the support routines Internal representation of floating point numbers Floats are in the standard 8087 32 bit format and doubles are in the standard 8087 64 bit format Copyright C 1983 by Manx Software Systems Page XIII 2 Aztec C86 SID86 Debugging Support The Digital Research SID86 symbolic debugger can be used with the Aztec C86 system The T option in the link edit step will create a symbol table Copyright 1983 c by Manx Software Systems PAGE XIV 1
35. d where a file name was expected LIBUTIL then continues reading input file names from the original command line Once LIBUTIL has finished its copy with replace function from the subject library to the new library it will append the input files which haven t been copied to the the new library in the same order in which it read their names from the command lines Copyright c 1983 by Manx Software Systems Page VI 6 Aztec C86 LIBUTIL LIBRARY UTILITY EXAMPLES l Let example lib be a library file on the default disk drive which contains the modules subl sub2 and sub3 To append the module in the file newsub o which is also on the default drive to example lib any ofthe following commands could be issued LIBUTIL oa example lib newsub LIBUTIL oa example lib newsub o LIBUTIL ao example lib newsub LIBUTIL a o example lib newsub o LIBUTIL o example lib a newsub After LIBUTIL is done there will be a new library file named example lib and it will contain the following modules in the order specified subl sub2 sub3 and newsub The module in the file newsub o doesn t have a name it only gets one when a copy of it is placed in a library The name of the module is derived from the name of the file in which it was originally contained by stripping that file name of the disk drive prefix and extent suffix In this example the name of the module which is appended to example lib is thus newsub Just to beat this example to death
36. d writing Same as r but the device or file may also be written to w Open for reading and writing Same as w but the device or file may also be read at Open for append and read Same as a but the device or file may also be read fprintf fprintf stream format argl arg2 FILE stream char format The function fprintf formats the caller s parameters as specified by the caller and writes the result to a device or disk file Formatting is done as described in chapter 7 entitled Input and Output of The C Programming Language AS ES The parameter stream identifies the device or file It contains the pointer which fopen returned to the caller When the device or file was opened for buffered i o The parameter format specifies how the formating is to Copyright 1983 c by Manx Software Systems Page VII 7 Aztec C86 LIBRARY FUNCTIONS fputs fread fscanf fseek be done The parameters argl etc are the parameters which are to be formatted int fputs cp stream char cp FILE stream The function fputs writes a character string to a device or disk file fputs uses the function aputc to write the string so newline translation may occur If the operation is successful fputs returns zero as its value Otherwise it returns EOF The parameter stream identifies the device or file It contains the pointer which was returned by fopen to the caller when the device or
37. difies the global integer errno unlink unlink name char namel Copyright 1983 c by Manx Software Systems Page VII 17 Aztec C86 LIBRARY FUNCTIONS The function unlink erases a file The parameter name is a pointer to a character array containing the name of the file to be erased unlink returns 255 as its value if the operation wasn t successful otherwise it returns a value in the range O to 3 Unlike many other i o functions unlink never modifies the global integer errno write write fd buf bufsize int fd bufsize char buf The write function writes characters to a device or disk file from the caller s buffer The characters are written to the device or file directly from the caller s buffer The parameter fd specifies the device or file It contains the file descriptor which was returned by the open function to the caller when the device or file was opened The parameter buf is a pointer to the buffer containing the characters to be written The parameter bufsize specifies the number of characters to be written If the operation is successful write returns as its value the number of characters written If the operation is unsuccessful write returns 1 and places a code in the global integer errno If the operation is successful errno is not modified For more information on the detailed operation of the write function when writing to the different devices and to disk files see the ch
38. ding to control Formating is done as described in chapter 7 Input and Output of The C Programming Language strcmp stremp strl str2 char strl str2 Compares strl to str2 and returns O zero if strings are equal 1 negative one if strl is less than str2 and 1 one if strl is greater than str2 strcpy strcpy dest src char dest src int max Copies the string pointed to by src into destination strlen strlen str char str Returns the length of str The length does not include the null at the end of the string strncmp strncmp strl str2 max char strl str2 int max Compares strl to str2 the same as strcmp but compares at most max characters strncpy Copyright 1983 c by Manx Software Systems Page VII 20 Aztec C86 LIBRARY FUNCTIONS strncpy dest src max char dest src int max copies the string pointed to by src into dest but copies at most max characters The destination may not be null terminated when copy is done 4 Utility Routines alloc char alloc size int size Allocates memory with size numer of bytes and returns pointer to beginning blockmv clear exit blockmv dest src length char dest src int dest Moves data from src to dest The number of bytes is specified by parameter length N o checking for overlap is performed clear area length value char area int length value Initializes length bytes starting at area with valu
39. e exit n int n Returns to the operating system Any streams which have been opened with fopen but not closed with fclose will be closed at this time If N is non zero then any submit that was in progress will abort format format function format argptr int function Copyright 1983 c by Manx Software Systems Page VII 21 Aztec C86 LIBRARY FUNCTIONS int e If c is upper case c is mapped to lower case and the new value returned otherwise c is returned toupper toupper c int c If c is lower case it is mapped to upper case and the new value returned otherwise c is returned 5 Operating System Interface bdos for MSDOS and PCDOS bdos ah dx cx int ah dx cx Calls the bdos by issuing int 21 with register AL set to al register AH set to 0 DX set to dx and CX set to cx The value returned in AL is the return value bdos for CPM86 bdos cx dx int cx dax Calls the bdos by issuing int 224 with register CX set to cx and register DX set to dx The value returned from the bdos in register AX is returned as the function value exit exit n int n Returns to the operating system Any streams which have been opened with fopen but not closed with fclose will be closed at this time N is the return code which is ignored in this release but may be used by future versions fcbinit fcbinit name fcbptr char name struct fcb fcbptr The _fcb structure is initialized to zeros and name
40. e The character is not sign extended so that the unique value EOF 1 is distinguishable from an Oxff byte in the file getchar C MACRO int getchar Returns the next character from standard input stdin gets char gets buffer char buffer Reads a line from the standard input The returned value is buffer All of the usual line editing facilities are Copyright 1983 c by Manx Software Systems Page VII 9 Aztec C86 LIBRARY FUNCTIONS available if input is from the console This is not the case with getchar Note the end of line sequence is not left in the buffer This is different from fgets for compatibility reasons getw int getw stream FILE stream Returns a word from stream The least significant byte is read first followed by the most significant byte Returns EOF if errors or end of file occur However since EOF is a good integer value errno should be checked to determine if an error has occurred printf printf format argl arg2 char format Formats data according to format and writes the result to the console Formating is done as described in chapter 7 Input and Output of The C Programming Language putc int putc c stream int c FILE stream Writes character c into stream at the current position Returns c if all is okay and returns EOF if an error occurs putchar int putchar c int c Writes c to the standard output stdout puts int puts cp char cp Writes string cp to the standard ou
41. e function calls which were described above and the read write posit and lseek function calls which are described below there are three other function calls which can be made creat to create a non existant file or to truncate an existing file so that it doesn t contain anything unlink to erase a disk file and rename to rename a disk file These function are described in the library functions chapter Programs call the functions read and write to transmit characters between the program and a disk file The transfer begins at the current position of the file and proceeds until the number of characters specified by the calling program have been transfered The current position of a file can be manipulated in various ways by a program allowing the program to access the file both sequentially and randomly To read a file sequentially from the beginning of the file the program simply issues repeated read requests After each read operation the current position of the file is set to the character following the last one returned to the calling program Similarly to write a file sequentially from the beginning of the file the program issues repeated write requests After each write operation the current position of the file is set to the character following the last one written Two additional functions lseek and posit are provided to allow programs to access files randomly lseek sets the current position of a file to a speci
42. e identifier and the extension For example if the input file is b subl o then the module name within the created library is subl Copyright c 1983 by Manx Software Systems Page VI 3 Aztec C86 _ LIBUTIL LIBRARY UTILITY When an input file is itself a library the member names in the created library are the same as the member names in the input library For example if an input file is a library containing modules subl sub2 and sub3 then the name of these modules in the created library are also subl sub2 and sub3 To specify that there are additional lines of lt input file lists gt a period surrounded by at least one space on either side must appear in the lt input file list gt on the first line of the command Of course LIBUTIL doesn t assume that such a period is a name it just acts as a flag to LIBUTIL specifying that there are additional lines of lt input file list gt s Also names can both preceed and follow the period flag The order in which modules are placed in the created library is specified by the order of the names in the input file lists If there is only one input file list for example subl o sub2 0 sub3 o where the input files each contain a single relocatable object module then the order of the modules in the library would be subl sub2 sub3 If an input module is itself a library then its modules are copied to the created library in the same order If there is only one input file list for ex
43. e lib Adding modules to a library and replacing modules in a library LIBUTIL can be told to add modules to a library or replace modules in a library by including one of the characters a or r in a dash parameter There is only one function which Copyright c 1983 by Manx Software Systems Page VI 5 Aztec C86 LIBUTIL LIBRARY UTILITY performs both an add operation and a replace operation Either character a or r causes LIBUTIL to perform the function The user also tells LIBUTIL either explicitly or implicitly the name of the library file on which the operation is to occur and gives LIBUTIL a list of files whose modules are to be added to or replaced in the library Each of these files can contain either a single relocatable object module or can be itself a library In the following paragraphs the library file on which the operation is to occur is called the subject library file and each file which is to be added or replaced is called an input file LIBUTIL proceeds as follows it creates a library file with a temporary name Then it copies modules one at a time from the subject library to the new library before copying each module it checks whether there is a file in the input file list whose name less drive specification and extent is the same as that of the module if not the module is copied If they do match LIBUTIL copies the contents of the matching file to the new library and the module from the subject
44. e object code to the file exmpl o The third command activates the Manx linker LN which links exmpl o getting any needed modules from the object library libc lib and writes the executable program to the file exmpl exe If the program in exmpl c performed floating point operations the command to link it would be LN exmpl o math lib libc lib Copyright 1983 c by Manx Software Systems Page II 1 AZTEC C86 OVERVIEW Figure 1 1 depicts the basic steps for producing a binary image of a C program It also indicates the path for producing and using run time subroutine libraries A Seance coal eosesL EDITOR fon onun c source file 7 y E E Aztec C86 compiler Hr assembly Il source file y E A dipenni Manx AS86 assembler po Seer Sie See Or A object file gt LIBUTIL librarian ice a ee ts ee esse See erie hm subroutine Manx LN Link Editor lt library A aeons aa Ty e exe lexecutable file _ Pa Figure 1 1 Developing C Programs with Aztec C86 under MSDOS or PCDOS and using the Manx assembler and linker Copyright 1983 c by Manx Software Systems Page II 2 AZTEC C86 OVERVIEW B Using Aztec C86 with MSDOS PCDOS and their assembler and linker The following commands can be entered to produce an executable file exmpl exe from the C language file exmpl c when using the MSDOS PCDOS assembler
45. e user can explicitly tell LIBUTIL the name of the library file to be listed by including the character o in a dash parameter in this case LIBUTIL assumes that the following parameter is the name of the library file The user can implicitly tell LIBUTIL which library file is to be listed by not including the character o in a dash parameter in this case LIBUTIL assumes that the file libc lib is to be listed LIBUTIL will not perform multiple functions during a single invocation For example you can t make it create a library and then list the contents with only a single activation of LIBUTIL you would have to activate it to create the library then activate it again to list the contents The parameter list to LIBUTIL when it is to perform a listing can include either one or two dash parameters If one is used then both the t character and the o character if specified are in it in this case they can appear in any order If two dash parameters are used then one contains the single character t and the other the single character o The only restriction in this case is that the name Of the library file must be the parameter string immediately following the dash parameter which has the o EXAMPLES LIBUTIL t lists the modules in the library file libc lib LIBUTIL ot example lib LIBUTIL t o example lib LIBUTIL o example lib t each of these three lines causes LIBUTIL to list the modules in the library exampl
46. earch debugger SID86 The name of the file to which the symbol table is sent is derived from that of the file containing the executable program by changing its extent to sym For example to link exmpl o and generate a symbol table in the file exmpl sym enter LN T exmpl o libc lib To link exmpl o send the output to foo exe and send a symbol table to foo sym enter Copyright 1983 c by Manx Software Systems Page V 2 AZTEC C86 LINKER LN T O foo exe exmpl o libc lib 3 C option This option specifies the starting address for the code portion of the output If not specified the starting code address is 3 In bytes 0 1 and 2 the linker places a jump instruction to begin which performs system initialization functions The starting code address immediately follows the C with no intervening spaces For example to link exmpl o where the code starts at 0X300 enter LN C300 exmpl o libc lib 4 D option This option specifies a starting address for the data and common segments in the data block It defaults to 0 The address immediately follows D with no intervening spaces 5 F option This option causes LN to merge the contents of a file with the command tail The name of the file follows the F with spaces between the two For example to link exmpl o subl o sub2 0 sub3 o and edit math lib and libc lib the following could be entered LN F exmpl ink where exmpl lnk contains
47. eger errno If it is successful errno is not modified The parameter stream identifies the device or file it contains the pointer which was returned by the function fopen when the device or file was opened for buffered i o Copyright 1983 c by Manx Software Systems Page VII 5 Aztec C86 LIBRARY FUNCTIONS The parameter buffer is a pointer to a character array into which fgets can put characters The parameter max is an integer specifying the maximum number of characters to be transferred fopen FILE fopen name how char name char how The function fopen prepares a device or disk file for subsequent buffered i o operations this is called opening the device or file If the device or file is successfully opened fopen returns as its value a pointer to a control block of type FILE When the user s program issues subsequent buffered i o calls to this device the pointer to its control block must be included in the list of parameters In the descriptions of the other buffered i o functions which require this pointer the FILE pointer is called stream If fopen can t open the device or file it returns the pointer NULL and sets an error code in the global integer errno If the open was successful errno isn t modified The parameter name is a pointer to a character array which contains the name of the device or file to be opened Under MSDOS or PCDOS the system console has the name con Other devic
48. entries enter C86 foo c E300 5 X option This option specifies the size in bytes of the macro table Each fdefine in a C program creates an entry in this table The default table size is 2000 bytes If the compiler aborts with error 59 you need a larger macro table The size of the macro table immediately follows the X with no intervening spaces For example to compile myprog c with a macro table of 3000 bytes enter C86 X3000 myprog c Copyright 1983 c by Manx Software Systems Page 111 3 AZTEC C86 COMPILER 6 Y option Specifies the maximum number of outstanding cases allowed in a switch statement Default size 100 outstanding cases If the compiler terminates with error 76 you need to recompile with more outstanding cases For example the following code segment will use four not five entries in the case table switch a case 0 a 1 break case l switch x case a functl a break case b funct2 b break a 5 case 3 funct2 a break The size of the case table immediately follows Y For example to compile exmpl c to allow 300 outstanding case statements enter C86 exmpl c Y300 7 Z2 option This option specifies the size in bytes of the string table The table defaults to 2000 bytes If the compiler terminates with error 2 the program requires a larger string table The size of the table immediately follows the Z with no interveni
49. erating system being used They also provide a byte stream orientated view of a file even under systems which do not support byte I O To use the standard I O package you should insert the statement kinclude libc h into your programs to define the FILE data type and miscellaneous other things needed to use the functions l Buffered File I O K R chapter 7 agetc int agetc stream FILE stream This is an ASCII version of getc which recognizes an end of line sequence CR LF and returns it as a single newline character n Also an end of file sequence control Z is recognized and returned as EOF This routine provides a uniform way of reading ASCII data across several different systems aputc int aputc c stream int c FILE stream ASCII version of putc which operates in the same manner as putc However when a newline n is put into the file an end of line sequence is written to the file CR LF Note If a partial data block is written as the last block in a file it is padded with an end of file sequence control Z before being flushed clrerror clrerror stream FILE stream Clears all error conditions on stream fclose int fclose stream FILE stream The function fclose informs the system that the user s program has completed its buffered i o operations on a Copyright 1983 c by Manx Software Systems Page VII 4 Aztec C86 LIBRARY FUNCTIONS device or file which it had previously opened
50. ere the possibility exists that either or both of them area device such as the console then the user s program should restrict itself to just issuing read and write function calls to these logical devices However if the operator always redirects the stdin or stdout i o to a disk file then the program can access the redirected device as it would a normal disk file That is it can reposition the current position of the logical device using the posit and or lseek function calls These calls are described below in the section on file i o When accessing any device or file including stdin stdout or stderr the user s program must include a file descriptor with the function call parameters which identifies the device with which the user s program wants to communicate In the case of devices and files other than stdin stdout and stderr the file descriptor is that which the open function returned to the user s program when it opened the device or file Since the user s program doesn t itself open the stdin stdout and stderr logical devices there has to be another way for it to determine the file descriptors to use when commincating with these devices The way is this to communicate with stdin use a file descriptor having value 0 for stdout use l and for stderr use 2 Copyright 1983 c by Manx Software Systems PAGE X 4 Aztec C86 Unbuffered 1 0 File I O When communicating with disk files in addition to the open and clos
51. es have their standard MSDOS PCDOS names Under CPM86 the devices which can be opened have the following names device name device con system console lst or prn line printer pun punch device rdr reader device The device name can be in upper or lower case When a disk file is to be opened the drive identifier in the name parameter is optional If its included the file is assumed to be on the specified drive otherwise its assume to be on the default drive The how parameter specifies how the user s program intends to access the device or file The allowed values and their meanings are Copyright 1983 c by Manx Software Systems Page VII 6 Aztec C86 LIBRARY FUNCTIONS how value meaning do ll Open for reading The device or file is opened If a file is opened its current position is set to the first character in the file If the device or file doesn t exist NULL is returned w Open for writing If a file is being opened and if it already exists it is truncated to zero length If it s a file and the file doesn t exist it is created a Open for append The calling program is granted write only access to the device or file For disk files if the file exists the its current position is set to the character which follows the last character in the file Also for disk files if the file doesn t exist it is created and its current position is set to the start of the file r Open for reading an
52. ever for programs for which UNIX compatibility is required since the UNIX creat function requires it In this case pmode should have an octal value of 0666 lseek long int lseek fd offset origin int fd origin long offset lseek sets the current position in the file specified by the fd parameter to the position specified by the offset and origin parameters The current position is set to the location specified by the origin parameter plus the offset specified by the offset parameter where the offset is a number of characters The value of the parameter origin determines the basis for the offset as follows Copyright 1983 c by Manx Software Systems Page VII 12 Aztec C86 LIBRARY FUNCTIONS open O offset is from beginning of file 1 offset from the current position 2 offset is from the end of file If lseek is successful it returns as its value the new current position for the file otherwise it returns l In the latter case the global integer errno is set to a symbolic value which defines the error The symbolic values which lseek may set in errno are EBADF if the fd parameter is invalid EINVAL if the offset parameter is invalid or if the requested current position is less than zero If lseek is successful errno is not modified Examples 1 To set the current position to the beginning of the file lseek fd OL 0 lseek returns as its value 0 meaning that the current position for the file is char
53. fied character location posit sets the current position to a specified record The program can then issue read and or write requests to transfer data beginning at the new current position If UNIX compatibility is a requirement don t use the function posit it s not supported by UNIX To perform a sequential update of a file a program would repeatedly perform the following sequence read in a buffer s worth of data update the buffer reset the current position in the file to the location before the read operation and finally write the buffer back to the file The sequence for updating a file randomly would be the same except that the program would explicitly set the current position of the file before each read operation Copyright 1983 c by Manx Software Systems PAGE X 5 Aztec C86 ASSEMBLY LANGUAGE SUPPORT A Imbedded Assembler Source Assembly language statements can be imbedded in a C program between an ASM and ENDASM statement Both statements must begin in column one No assumptions should be made concerning the contents of registers The environment should be preserved and restored Caution should be used in writing code that depends on the current code generating techniques of the compiler There is no guarantee that future releases will generate the same or similar patterns B Assembler Subroutines The calling conventions used by the Aztec C86 compiler are very simple The arguments to a function are pushed o
54. file was opened for buffered i o The parameter cp is a pointer to a character array containing the string to be written int fread buffer size count stream char buffer int size count FILE stream Reads count items of size bytes into buffer from stream Returns the number of items actually read int fscanf stream control argl arg2 FILE stream char control Formats data according to control Data is read from stream file Formating is done as described in chapter 7 Input and Output of The C Programming Language int fseek fp pos mode FILE fp long pos int mode Copyright 1983 c by Manx Software Systems Page VII 8 Aztec C86 LIBRARY FUNCTIONS Positions the stream according to pos and mode Mode is interpreted as follows O seek from 0 Pos is treated as an unsigned number and fp is positioned pos bytes from the beginning of the file l seek relative from the current position 2 seek relative from the end of the file ftell long ftell stream FILE stream Returns the current byte position of stream from the beginning of the file fwrite int fwrite buffer size count stream char buffer int size count FILE stream Writes count items of size bytes from buffer into stream Returns the number of items actually written getc int getc stream FILE stream Returns the next character from stream The unique value EOF is returned if an error is encountered or when reaching end of fil
55. g disk is created by copying the following files from the distribution disk to the working disk C86 CMD AS86 CMD LN CMD LIBC LIB Copyright c 1983 by Manx Software Systems Page I 1 Aztec C86 INSTALLATION MATH LIB LIBC H Copyright c 1983 by Manx Software Systems Page I 2 AZTEC C86 OVERVIEW OVERVIEW This chapter describes the basic procedure for generating an executable version of a C program Section A describes the procedure for using Aztec C86 with MSDOS PCDOS and the Manx assembler and linker Section B describes the procedure when using Aztec C86 with MSDOS or PCDOS and their assembler and linker Section C describes the procedure when using CP M 86 Section D describes the creation of object file libraries The use of the compiler assembler linker and object file librarian are described in more detail in subsequent chapters A Using Aztec C86 with MSDOS PCDOS and the Manx assembler and linker The following commands will produce an executable file EXMPL EXE from the file EXMPL C which contains a C source program C86 exmpl c AS86 exmpl asm LN exmpl o libc lib This procedure is depicted in figure 1 1 The first command activates the compiler C86 which compiles the program in exmpl c and writes the assembly language source to an intermediate file exmpl asm The second command activates the Manx assembler AS86 which assembles the code in the intermediate file and writes the resulting relocatabl
56. ght 1983 c by Manx Software Systems PAGE X 1l Aztec C86 Unbuffered 1 0 Console I O There are two ways for a program to access the system console using UNIX compatible i o functions One is to issue read and write calls to the logical devices stdin stdout and or stderr These three devices are opened by the Aztec system before a user s program gains control Thus the user s program can access these devices without performing an initial open function on them and without performing a close function on them before terminating The default condition is for these logical devices to all be the system console However the operator when activating the user s program can specify that the stdin or stdout logical device be associated with another device or a disk file that is that the stdin and stdout i o be redirected Thus if the user s program must communicate with the operator and can t be assured that the stdin and or stdout i o has been redirected then the program must use the other method of communicating with the console which is described in this section For more information on using the UNIX compatible i o functions to communicate with the stdin stdout and stderr devices see the appropriate section which follows The other method for a program to access the system console is to explicitly open the console issue read and write function calls to it and then close it The open and close calls were described above s
57. ght 1983 c by Manx Software Systems Page VII 26 Aztec C86 LIBRARY FUNCTIONS sin The arguments must meet the following requirements x Cannot be less than zero if x equals zero y must be greater than zero if x is greater than zero then 354 8 lt y log x lt 349 3 If pow is unable to perform the calculation it sets a code in the global integer ERRNO and returns an arbitrary value otherwise it returns the computed number as its value without modifying ERRNO Table 2 6 1 lists the symbolic codes which pow may set in ERRNO the associated value returned by pow and the meaning Table 2 1 1 Error codes returned in ERRNO by pow Code pow x y Meaning EDOM 5 2e151 x lt 0 or x y 0 ERANGE 5 2e151 y log x gt 349 3 ERANGE 0 0 y log x lt 354 8 double sin x double x sin is a function of one argument which when called returns as its value the sine of the argument The value returned is of type double The argument is in radians and its absolute value must be less than 6 7465e9 The type of the argument is double If sin can t perform the computation it returns an arbitrary value and sets a code in the global integer ERRNO otherwise it returns the computed number without modifying ERRNO Table 2 7 1 lists the symbolic codes which sin may set in ERRNO the associated values returned by sin and the meaning Table 2 1 1 Error codes returned in ERRNO by sin ERANGE 0 0 labs x
58. guments can assume any real values except that x and y Cannot both be zero If x equals zero the value returned is also zero If atan2 can t perform the computation it returns an arbitrary value and sets a code in the global integer ERRNO otherwise it returns the computed value without modifying ERRNO Table 2 12 1 lists the symbolic codes which atan2 may set in ERRNO the associated values returned by atan2 and the meaning Table 2 1 1 Error codes returned in ERRNO by atan2 sinh double sinh x double x sinh is a function of one argument which returns as its value the hyperbolic sine of the argument The returned value is of type double The absolute value of the argument must be less than 348 606839 and is of type double If sinh can t perform the computation it sets a code in the global integer ERRNO and returns an arbitrary value otherwise it returns the computed value without modifying ERRNO Table 2 13 1 lists the symbolic codes which sinh may set in ERRNO the value returned by sinh and the meaning Copyright 1983 c by Manx Software Systems Page VII 31 Aztec C86 LIBRARY FUNCTIONS Table 2 1 1 Error codes returned in ERRNO by sinh Code sinh x Meaning ERANGE 5 2e151 abs x gt 348 606839 cosh double cosh x double x cosh is a function of one argument which returns as its value the hyperbolic cosine of the argument The value returned is of type double The absolute value of the argume
59. he object code to b exmpl o enter C86 exmpl c O b exmpl o or C86 O b exmp1 086 exmpl c Still under CP M 86 to compile exmpl c send the assembly language output to exmpl a86 and not activate the assembler automatically enter C86 exmpl c A Copyright 1983 c by Manx Software Systems Page III 2 AZTEC C86 COMPILER Still under CP M 86 to compile exmpl c send the assembly language output to b exmpl a86 and not activate the assembler automatically enter C86 exmpl c A O b exmpl a86 2 M option This option causes the compiler to generate assembler source for the Microsoft MASM assembler For example to compile exmpl c and then assemble the resulting assembler source file exmpl asm enter C86 M exmpl c MASM exmpl 3 T option This option causes the compiler to copy the C source statements to the assembly language source file as comments The C comment in the assembly language file is followed by the assembly language code generated from it If not specified the compiler doesn t copy C source statements to the assembly language file 4 E option Specifies the number of entries in the expression work table The default size is 120 entries Each entry uses 14 bytes If the compiler terminates with error 36 the expression work table has overflowed The size of the table immediately follows E with no intervening spaces For example to compile foo c with an expression work table of 300
60. ibrary Em o exe Figure 2 2 Developing C Programs with Aztec C86 under MSDOS or PCDOS and using their assembler and linker Copyright 1983 c by Manx Software Systems Page II 4 AZTEC C86 OVERVIEW C Using Aztec C86 with CP M 86 The following commands can be entered to produce an executable file exmpl cmd from exmpl c C86 exmpl c LN exmpl o libc lib The first command activates the compiler C86 which compiles the C program in exmpl c and writes the resulting assembly language source to the intermediate file tmp C86 then activates AS86 which assembles the code in the intermediate file and writes the resulting object code to the file exmpl o The second command activates the Manx linker LN which links exmpl o getting any needed modules from the object library libc lib and writes the executable program to exmpl cmd If the exmpl program performed floating point operations the link command would be LN exmpl o math lib libc lib D Object libraries The Manx linker LN can link any number of object files together One way to do this is to explicitly tell LN of each object module which is to be linked together Another way is to place commonly used modules in an object file library using the Aztec object file librarian LIBUTIL When a program is linked which requires modules which are in the library just include the object file library in the list of files passed to LN LN will search the lib
61. it fd 3 read Copyright 1983 c by Manx Software Systems Page VII 16 Aztec C86 LIBRARY FUNCTIONS read fd buf bufsize int fd bufsize char buf The read function reads characters from a device or disk file into the caller s buffer In most cases the characters are read directly into the caller s buffer The fd parameter specifies the file it contains the file descriptor which was returned to the caller when the file was opened The parameter buf is a pointer to the buffer into which the characters from the deive or file are to be placed The parameter bufsize specifies the number of characters to be transfered If the read operation is successful it returns as its value the number of characters transfered If the operation isn t successful read returns 1 and places a code in the global integer errno For more information see the description on the unbuffered read operation for the various devices and for disk files in the chapter on unbuffered i o rename rename oldname newname char oldnamel newname j The function rename changes the name of a file The parameter oldname is a pointer to a character array containing the old file name and newname is a pointer to a character array containing the new name of the file If a file with the new name already exists it is erased before the rename occurs The value returned by rename is undefined Unlike many other i o functions rename never mo
62. l be from newlib lib The first sub3 module in the new example lib will be from the original example lib and the second will be from newlib lib The point being exemplified is that LIBUTIL will not replace modules in the original library with modules from an input library it will only append modules in the input library to the subject library 3 Let example lib be a library containing the modules subl sub2 and sub3 To replace module sub2 with the contents of the file named sub2 o and to append the modules in the library file newlib lib which are modl mod2 and mod3 and the module in the file newsubl o to example lib any of the following commands could be entered LIBUTIL oa example lib sub2 newlib lib newsubl LIBUTIL a o example lib sub2 o newlib lib newsubl o After LIBUTIL is done there will be a new example lib file and it will contain the following modules in the order specified subl sub2 sub3 modl mod2 mod3 and newsubl The sub2 module in the new example lib is the same as that in sub2 0 4 Let example lib be a library containing the modules subl sub2 and sub3 The following submit file when activated will cause LIBUTIL to replace module sub2 with the module in file sub2 0 and append the modules in the library newlib lib which are modl mod2 and mod3 and the modules in the files newsubl o newsub2 0 newsub3 o newsub4 0 newsub5 o newsub6 0 and newsub7 o xsub LIBUTIL oa example lib newsubl o
63. language The system includes a full feature C compiler a relocating assembler a linkage editor an object library maintenance utility plus an extensive set of run time library routines Also included are interfaces to the MSDOS PCDOS assembler MASM and Digital Research s SID86 debugging system 1 4 Brief System Overview The Aztec C86 compiler is a complete implementation of UNIX version 7 C with the exception of the bit field datatype The compiler produces assembly language source code which can be read by the Manx AS86 assembler or the PCDOS MSDOS assembler MASM Programs generated by the compiler have a physical code segment and a physical data segment each of which can be up to 64 K bytes long The Manx AS86 relocating assembler accepts the same language as the PCDOS MSDOS assembler and the Intel AS86 assembler It has support for codemacros but not for macros The assembler is used Copyright c 1983 by Manx Software Systems Page I 1 Aztec C86 Introduction to assemble the output of the compiler and for writing assembly language subroutines to be combined with C routines The relocatable object files produced by the assembler are combined with other relocatable files and library routines by the Manx LN linkage editor The linkage editor will scan through one Or more run time libraries and incorporate any routines that are referenced by the linked modules The Aztec C86 system also includes LIBUTIL an object li
64. le name to fopen and open Any 1 0 to the returned file pointer fp or file descriptor fd will be directed to the specified device For example using CPM86 the following program will send a message to the printer Copyright 1983 c by Manx Software Systems PAGE IX 1 Aztec C86 Buffered I O I O Redirection tinclude libc h main char c FILE f1 fl fopen l1st w fputs this is going to the list device LST n fl There are a number of library routines for buffered 1 0 The reader is directed to the LIBRARY section of this manual and chapter 7 of The C Programming Language for more information Copyright 1983 c by Manx Software Systems PAGE IX 2 Aztec C86 Unbuffered 1 0 Unbuffered I O This section describes how a program accesses devices and files using the functions defined in chapter 8 of the K amp R text A program which acccesses devices and files using these functions will also be able to run on a UNIX system The basic input output support functions allow a program to access the console printer reader punch and the files on any disk The support functions are creat creates a disk file unlink deletes a disk file rename renames a disk file open prepares a device or file for 1 0 close concludes the I O operations on a device or file read reads data from a device or file write writes data to a device or file posit positions a disk file to a specific record lseek positions a disk file to a
65. luded in the user s program Writing to the system console the line printer or the punch To send characters to the system console the line printer or the punch device a program calls the function write passing it as parameters the file descriptor which was passed to it by the function open when it opened the device the address of a buffer containing characters to be sent and an integer specifying the number of characters to be sent The write function sends the characters directly to the device and returns as its value the number of characters sent If the write function encounters a carriage return Character in the caller s buffer it sends it to the device then sends a line feed character then continues with the next character in the caller s buffer If the write function detects an error it returns l as its value and places an error code in the global integer errno If an error was not detected errno is not modified The only symbolic value which write may place in errno is EBADF signifying that an invalid file descriptor was passed to write The file errno h defines the integer value of EBADF Reading from the reader device A program gets characters from the reader device by calling the read function passing it as parameters the file descriptor which was passed to it by open when it opened the reader device the address of a buffer into which characters from the device are Copyright 1983 c by Manx Software S
66. mer Information The Manx AS86 assembler accepts the same assembly language as does the MSDOS PCDOS assembler MASM and as does the Intel ASM86 assembler with the exceptions noted below The Intel assembler is defined in their manual ASM86 Language Reference Manual order Copyright 1983 c by Manx Software Systems Page IV 2 Aztec C86 ASSEMBLER number 121703 002 The exceptions are l Statement names Can be up to 255 characters and all characters are part of the name not just the first 32 characters as in the MSDOS PCDOS and Intel assemblers Global symbols however while they can contain up to 255 characters within a single program are truncated to 8 characters in the object file Thus if A program has an entry point named A very long label within the program it is refered to by its full name Other programs in other files would refer to the entry point using its truncated name A very 1 2 Statement names are Case sensitive ie the label A label is different from the label a label All other symbols instructions register names Operators aren t 3 Only two physical segments are allowed all logical segments ie those defined within a program using the segment directive with class name code go in the code physical segment all other logical segments go in the data physical segment 4 In the MSDOS PCDOS and Intel assemblers code within a logical segment is contiguous in memory even if a segment i
67. nbuffered I O but is easier to use There are three standard files in Aztec C86 stdin stdout and stderr When a program is started these three files are opened automaticaly and file pointers are provided for them The getchar and scanf functions read from the stdin file The putchar and printf functions output to the stdout file Run time error messages are directed to stderr The default device for stdin stdout and stderr is CON The destination for stdin and stdout can be redirected to a disk file or another device To redirect stdin specify on the command line a lt followed by the file name or device for example myprog parml parm2 lt input fil When myprog executes all getchar requests and scanf requests will read from file input fil To redirect stdout specify on the command line a gt followed by the file name or device for example myprog parml parm2 gt prn When myprog executes all output requests to putchar and printf will be directed to the printer device PRN stdin and stdout can be used just as any other file pointer Any I O performed with these file pointers will be redirected if redirection was requested I O can be redirected to any file or device Under PCDOS and MSDOS the console is referred to as con other devices are called by their standard PCDOS MSDOS names Under CP M 86 devices have these names CON LST PRN PUN RDR Devices can be specified as the fi
68. newsub7 sub2 newsub2 newsub3 newsub4 newlib lib newsub5 newsub6 After LIBUTIL is done there will be a new example lib containing the following modules in the specified order subl sub2 sub3 newsubl newsub2 newsub3 newsub4 modl mod2 mod3 newsub5 newsub6 newsub7 The module sub2 will be a copy Of that in the file sub2 o Copyright c 1983 by Manx Software Systems Page VI 8 Aztec C86 LIBRARY FUNCTIONS STANDARD LIBRARY FUNCTIONS A SUMMARY 1 Buffered File I O K amp R chapter 7 agetc stream ASCII version of getc aputc c stream ASCII version of putc clrerror stream clear error on stream fclose stream closes an I O stream feof stream eof on stream ferror stream error on stream fgets buffer max stream reads text from stream to buffer fopen name how opens file name according to how fprintf strm format argl writes formatted print to stream fputs cp stream writes string cp to stream fread buf SZ cnt strm reads cnt items from strm to buffer fscanf fp control pl p2 converts input string fseek stream pos mode positions stream to pos ftell stream returns current file position fwrite buf sz cnt strm writes count items from buf to strm getc stream gets a character from file stream getchar read from standard input gets buffer reads a line from the console getw stream returns a word from stream printf format argl arg2 writes formatted data on cons
69. ng spaces For example to compile foo c with a 3000 byte string table enter C86 Z3000 foo c 8 S option By default Aztec C86 expects that pointer references to members within a structure are limited to the structure associated with the pointer To support programs written for other compilers where this is not the case the S option is provided If S is specified as a compile time option and a pointer reference is to a structure member name that is not defined in the strcture Copyright 1983 c by Manx Software Systems Page III 4 AZTEC C86 COMPILER associated with the pointer then all previously defined structures will be searched until the specified member is found The search will begin with the structure most recently defined and search backwards from there 9 L option This option specifies the number of entries allowed in the local symbol table It defaults to 40 entries Each entry requires 26 bytes If the compiler aborts with the message local symbol table full the program being compiled requires a larger local symbol table The number of entries immediately follows the L with no intervening spaces For example to compile exmpl c with a local symbol table having 100 entries enter C86 L100 exmpl c 10 D option This option allows a symbol or macro to be defined to the compiler as if it had been a fdefine statement in a program The syntax is Dstringl string2 where stringl is the
70. nt must be less than 348 606839 and it must be of type double If cosh can t perform the computation it returns an arbitrary value and sets a code in the global integer ERRNO otherwise it returns the computed value without modifying ERRNO Table 2 14 1 lists the symbolic codes which cosh may set in ERRNO the associated values returned by cosh and the meaning Table 2 1 1 Error codes returned in ERRNO by cosh Code cosh x Meaning ERANGE 5 2e151 abs x gt 348 606839 tanh double tanh x double x tanh is a function of one argument which returns as its value the hyperbolic tangent of its argument The value returned is of type double The argument can be any real number whatsoever It must however be of type double Unlike some of the other math functions tanh never modifies ERRNO and always returns the computed value Copyright 1983 c by Manx Software Systems Page VII 32 Aztec C86 LIBRARY FUNCTIONS random double random returns a random number in the range O to l Copyright 1983 c by Manx Software Systems Page VII 33 Aztec C86 ERROR CODES ERROR PROCESSING During run time two variables are used to enhance error handling An external variable errno is an integer that is set to an error code by the I O and scientific math routines flterr is set to indicate floating point arithmetic errors flterr set to O indicates a good result a non zero value indicates a bad result See the sec
71. nterminated string 4 compiler error in effaddr 5 illegal type for function 6 inappropriate arguments 7 bad declaration syntax 8 name not allowed here 9 must be constant 10 size must be positive integer 11 data type too complex 12 illegal pointer reference 13 unimplemented type 14 unimplemented type 15 storage class conflict 16 data type conflict 17 unsupported data type 18 data type conflict 19 too many structures 20 structure redeclaration 21 missing s 22 struct decl syntax 23 undefined struct name 24 need right parenthesis 25 expected symbol here 26 must be structure union member 27 illegal type CAST 28 incompatable structures 29 structure not allowed here 30 missing on expr 31 call of non function 32 illegal pointer calculation 33 illegal type 34 undefined symbol 35 Typedef not allowed here 36 no more expression space see COMPILER E option 37 invalid expression 38 no auto aggregate initialization 39 no strings in automatic 40 this shouldn t happen 41 invalid initializer 42 too many initializers 43 undefined structure initialization 44 too many structure initializers 45 bad declaration syntax 46 missing closing bracket 47 open failure on include file 48 illegal symbol name 49 already defined 50 missing bracket Copyright 1983 c by Manx Software Systems Page III 7 AZTEC C86 COMPILER must be lvalue symbol table overflow multiply defined label too many labels missing quote missing apostrophe line
72. nto the stack in reverse order i e the first argument is pushed last and the last argument is pushed first The function is then called using a near call instruction When the function returns the arguments are removed from the stack A function is required to return with the arguments still on the stack unless something is pushed back in place of them The segment registers and registers BP SI and DI must be preserved by routines called from C If the function returns an integer as its value it is returned in register AX long integers are returned in the primary long register and doubles in the primary floating point register For examples of assembly code called by C programs refer to the string asm and toupper asm files supplied with the package Example Copyright C 1983 Thomas Fenwick Cg group CODESEG CODESEG segment word public code assume cs Cg public isupper _ isupper proc near mov bx sp mov al 2 bx cmp al A jl false cmp ar Zz jg false true sub ax ax inc ax ret public islower islower_ o mov bx sp mov al 2Lbx cmp al a jl false cmp al z Copyright c 1983 by Manx Software Systems Page XI l Aztec C86 ASSEMBLY LANGUAGE SUPPORT jle true false sub ax ax ret ret isupper_ endp CODESEG ends end Copyright c 1983 by Manx Software Systems Page XI 2 Aztec C86 Data Formats Data Formats l character Characters are 8 bit ASCII Strings are terminated by a NULL X 00
73. o the rest of this section just covers the details of reading and writing to the console Console input To read characters from the system console a program issues read function calls passing as parameters the file descriptor which was returned to the program when it opened the console the address of a character buffer into which characters from the console are to be placed and a number which specifies the maximum number of characters to be returned to the program The read function will place characters in the buffer as described below and return as its value an integer specifying the number of characters placed in the buffer The system maintains an internal 256 character buffer into which it reads console keyboard input The read function returns characters to the calling program from this buffer If the internal buffer is empty when a program requests console input the read function will perform its own read operation to the console putting the characters obtained in its internal buffer While the read function s read operation is in progress the console operator can use the normal editing characters such as rub out backspace etc These editing characters do not appear in the internal read buffer The read function s read operation terminates when the operator depresses the carriage return key the line feed key or ctl z or when there are 256 characters in the internal buffer Following the characters in the internal buffer whi
74. ole putec c stream writes character c into stream putchar c writes to standard output puts cp writes string cp onto console putw c stream writes a word c to stream scanf control pl p2 formats input from standard in sscanf str control pl p2 reverse of sprintf ungetc c stream pushes c back into stream 2 Unbuffered I O K amp R chapter 8 close fa closes file fd creat name mode creates a file lseek fd pos mode positions file desc according to mode open name rwmode opens file according to read write mode posit fd num positions file fd to number record read fd buf BUFSIZE reads from fd to buf BUFSIZE bytes rename oldname newname renames a disk file unlink filename erases a disk file Copyright 1983 c by Manx Software Systems Page VII 1 Aztec C86 write 3 atof atoi atol ftoa index rindex strcmp strcpy strlen strncmp strncpy 4 alloc blockmv clear exit format isdigit islower isupper sprintf tolower toupper 5 bdos exit fcbinit settop 6 acos asin atan atan2 cos cosh cotan exp log logl10 pow random sin sinh Copyright fd buf BUFSIZE String Manipulation cp cp cp m cp cp strl dest cp strl dest Utility size dest area n func c c c buff c c Cp c c prec type str2 src str2 max src max Routines src length length value form
75. oooooooooooooooooooonooooooooonoooooo XII Floating Point Support sica andas ado ros XIII SID Support E E E O EO O6O OC L LO O 0 0U000000000000000000000u0N 0 0000000 _ XIV Copyright C 1983 by Manx Software Systems Aztec C86 INSTALLATION INSTALLATION To begin using Aztec C86 we recommend that you first create a working disk by copying the files listed below from the distribution disk onto the working disk We recommend that you then compile assemble link and execute the supplied sample program EXMPL C This procedure is described in chapter 2 To execute the program after it has been created type EXMPL The program will display enter your name When you enter your name followed by a carriage return the program will display a simple greeting Your Aztec C86 system is now installed and ready to go A INSTALLING AZTEC C86 FOR USE WITH MSDOS OR PCDOS When your operating system is MSDOS or PCDOS Aztec C86 Can be used with either the Manx assembler and linker or with the MSDOS PCDOS assembler MASM and linker LINK When the Manx assembler and linker are to be used the following files should be copied onto your working disk C86 EXE AS86 EXE LN EXE LIBC LIB MATH LIB LIBC H When the MSDOS PCDOS assembler and linker are to be used the following files should be copied onto the working disk C86 EXE LIBCMS LIB MATHMS LIB LIBC H B INSTALLING AZTEC C86 FOR USE WITH CPM86 A CPM86 workin
76. rary and automatically copy modules from it which are needed Only the needed modules will be copied Any number of object libraries can be searched by LN Aztec C86 for MSDOS and PCDOS comes with four object libraries LIBC LIB is used when linking any program using LN MATH LIB is used when linking any program using LN which performs floating point operations LIBCMS LIB is used when linking any program using the MSDOS or PCDOS assembler LINK MATHMS LIB is used when linking any program using LINK which performs floating point operations Aztec C86 for CP M 86 comes with two object libraries LIBC LIB is used when linking any program using LN Copyright 1983 c by Manx Software Systems Page II 5 AZTEC C86 OVERVIEW MATH LIB is used when linking any program using LN which performs floating point operations Copyright 1983 c by Manx Software Systems Page II 6 AZTEC C86 COMPILER C86 COMPILER The Aztec C86 compiler uses the book The C Programming Language by Brian W Kernighan and Dennis M Ritchie for a programmer s reference manual This book can be also be used as a tutorial for learning C A Operating Instructions C86 is activated by entering C86 lt command tail gt where lt command tail gt specifies the name of the file containing the C program and dash options that is optional flags and parameters which override default compiler assumptions The source file name and each of the dash options a
77. re separated by spaces All dash options begin with a dash immediately followed by a letter which defines the option After that the syntax differs for the various dash options For some that s all there is For others a number follows which is the value of the option In another case the next field is a file name The dash options are described below The compiler generates assembly language code and sends it to a disk file There are some differences in it s operation when using MSDOS PCDOS and when using CP M 86 Under MSDOS and PCDOS the assembly language code by default is sent to the file whose name is the same as that of the C language source file with the extent changed to asm This default file name can be overriden using the O option described below For example to compile the program in foo c and send the assembler source code to foo asm when using PCDOS enter C86 foo c Under CP M 86 by default the assembly language source code is sent to an intermediate file named tmp and the MANX AS86 assembler is activated The assembler generates object code sending it to a file whose name is the same as that of the C language source file with extent o This default name for the object file can be overriden using the 0O option described below For example to compile and assemble the program in mycprog c and send the object code to mycprog o when using CP M 86 enter C86 exmpl c Also under CP M 8
78. ry example lib including all modules contained within it into relocatable object files O example lib x NB It should be noted that when copying a single module the LIBUTIL executes the command and returns When copying a complete library the LIBUTIL lists the modules being copied to replace a library module with the contents of a relocatable object file the following replaces the library module subl with the relocatable object file subl o o example lib r subl o 6 LIBUTIL o library name USE FUNCTION gt xsub to create a library using an extended command line the following creates a library charles lib and appends to it subl o sub2 0 sub3 0 sub4 o etc Copyright c 1983 by Manx Software Systems Page VI 2 Aztec C86 LIBUTIL LIBRARY UTILITY LIBUTIL o charles lib subl o sub2 0 sub3 0 sub4 o B DETAILED EXPLANATION Creating a Library The command for creating a library has the following two formats format 1 LIBUTIL o lt output library name gt lt input file list gt format 2 LIBUTIL o lt output library name gt lt input file list gt one or more lists each an lt input file list gt If the optional parameter o lt output library name gt is specified the name of the file containing the library to be created is lt output library name gt if this parameter is not specified the name of the file containing the library to be created is libc lib In either case LIBUTI
79. s Page VII 28 Aztec C86 LIBRARY FUNCTIONS cotan double cotan x double x cotan is a function of one argument which when called returns as its value the cotangent of the argument The returned value is of type double The argument is in radians and its absolute value must be greater than 1 9le 152 and less than 6 7465e9 The type of the argument is double If cotan can t perform the computation it returns an arbitrary value and sets a code in the global integer ERRNO otherwise it returns the computed value without modifying ERRNO Table 2 9 1 lists the symbolic codes which cotan may set in ERRNO the associated value returned by cotan and the meaning Table 2 1 1 Error codes returned in ERRNO by cotan Code cotan x Meaning ERANGE 5 2e151 0 lt x lt 1 9le 152 ERANGE 5 2e151 1 9le 152 lt x lt 0 ERANGE 0 0 labs x gt 6 7465e9 asin double asin x double x asin is a function of one argument which when called returns as its value the arcsine of the argument The returned value is of type double The absolute value of the argument must be less than or equal to 1 0 Its type is double If asin can t perform the computation it returns an arbitrary value and sets a code in the global integer ERRNO otherwise it returns the computed value without modifying ERRNO Table 2 10 1 lists the symbolic codes which asin may set in ERRNO the associated values returned by asin and the
80. s closed another opened and closed and the first reopened In AS86 the only segments for which this is true is segments whose combinability type is common Code in other segments is placed in memory in the order encountered in the program For example consider this program datasegl segment varl db datasegl ends dataseg2 segment var2 db dataseg2 ends datasegl segment var3 db datasegl ends With AS86 varl var2 and var3 will be located in memory in the order in which they appear in the program that is varl var2 var3 This is not true for segments having combinability type common If datasegl was of type common the variables would be grouped in memory in this order varl var3 var2 5 The ASSUME directive has no function with AS86 it s accepted but nothing is done with it AS86 and LN assume that the CS segment register points to the physical code segment and DS SS and ES point to the physical data segment 6 Codemacros are supported by AS86 as defined by the Intel Copyright 1983 c by Manx Software Systems Page IV 3 Aztec C86 ASSEMBLER ASM86 Language Reference Manual order number 121703 002 and are similar to those of the Digital Research ASM86 assembler but the DBIT directive of the Digital Research assembler isn t supported instead the RECORD directive of the Intel assembler is supported 7 Floating point instructions are not supported by AS86 You can make AS86 support them by in
81. specific character Generally to access a device or file a program first must call the open function passing it the name of the device or file and a code indicating the type of operations the program intends to perform Open returns a file descriptor which the program must include in the parameters which are passed to other functions when accessing the device or file This file descriptor is an integer which is an index into a table called the channel table Each entry in this table is a control block describing a device or file on which the program is performing I O operations For more details on the open function see the chapter on the unbuffered i o functions The only exception to the rule requiring the opening of devices and files prior to the issuance of program i o with them regards the logical devices stdin stdout and stderr When the program first gets control these logical devices have already been opened by the system hence the program can issue i o calls to them without opening them itself Generally after a program has completed its i o to a device or file it must call the close function to allow the system to release the control blocks which it has allocated to the device or file The only exception to this rule is that the logical devices stdin stdout and stderr never need be closed In the remainder of this section the details of program i o to the various devices and disk files are presented Copyri
82. the file must already exist fd open b sample ext O RDONLY 4 To open the file subl c on the default drive for read write access if the file doesn t exist it will be created first Copyright 1983 c by Manx Software Systems gt Page VII 15 Aztec C86 LIBRARY FUNCTIONS fd open subl c O _RDWR 0_CREAT 5 To create the file main txt if it doesn t exist or to truncate it to zero length if it already exists and then to open it for write only access fd open main txt O WRONLY 0O_ TRUNC posit posit fd num int fd num posit will set the current position for a disk file toa specified 128 byte record This function should not be used when UNIX compatibility is required because it isn t supported by UNIX The parameter fd identifies the file fd is the file descriptor which was returned to the caller by open when the file was opened The parameter num is the number of the specified record where the number of the first record in the is zero If posit is successful it returns O as its value If no error occurs posit returns l and sets an error code in the global integer errno The only symbolic value which may be set in errno is EBADF in response to a bad file descriptor If no error occurs errno isn t modified Examples l to set the current position to the first byte in the first record posit fd 0 2 To set the current position to the first byte of the fourth record pos
83. tion on floating point support for more details errno is set to 0 at the beginning of each I O request and is set to a non zero value if an error occurred errno is set to a non zero value if an error occurred in processing a scientific math function see section VI Library Functions for more information The definition for the various settings for errno is in file errno h The following is the contents of errno h for v1 05 of Aztec C86 int errno define ENOENT 1 file does not exist define E2BIG 2 not used define EBADF 3 bad file descriptor file is not open or improper operation define ENOMEM 4 insufficient memory for requested operation define EEXIST 5 file already exists on create request define EINVAL 6 invalid argument define ENFILE 7 exceeded maximum number of disk files define EMFILE 8 exceeded maximum number of file descriptors define ENOTTY 9 not used define EACCES 10 invalid access request define ERANGE 20 invalid argument to math function function value can t be computed define EDOM 21 invalid argument to math function argument value illegal by definition Copyright c 1983 by Manx Software Systems Page VIII 1 Aztec C86 Buffered I O I O Redirection I O Redirection and Buffered I O C has two basic types of I O namely buffered sometimes called stream 1 0 and unbuffered Unbuffered I 0 is discussed in another section Buffered I O tends to be less efficient than u
84. tput stdout n is appended to the end of the string before sending it putw int putw c stream int c FILE stream Copyright 1983 c by Manx Software Systems Page VII 10 Aztec scanf C86 LIBRARY FUNCTIONS Writes a word c to stream The least significant byte is written first followed by the most significant byte Returns cif all is okay and EOF if error occurs However Since EOF is a good integer value errno should be checked to determine if an error has occurred int scanf control argl arg2 char control Formats data according to control Data is read from standard in Formating is done as described in chapter 7 Input and Output of The C Programming Language ungetc int ungetc c stream int c FILE stream Pushes c back onto stream so that the next call to getc will return c Normally returns c and returns EOF if c cannot be pushed back Only one character of push back is guaranteed and EOF cannot be pushed back 2 Unbuffered 1 0 close Unbuffered I O is described in chapter 8 of The C Programming Language by Brian W Kernighan and Dennis M Ritchie the chapter is captioned The UNIX System Interface close fd int fd An open device or disk file is closed The parameter fd specifies the device or file to be closed It is the file descriptor which was returned to the caller by the open function when the device or file was opened If the close operation is successf
85. ul close returns as its value the value of the fd parameter If the close operation fails close returns 1 and sets a code in the global integer errno If the close was successful errno is not modified The only symbolic value which close may set in errno is EBADF meaning that the file descriptor parameter was invalid Copyright 1983 c by Manx Software Systems Page VII 11 Aztec C86 LIBRARY FUNCTIONS creat creat name pmode char name int pmode The function creat creates a file and opens it for write only access If the file already exists it is truncated so that nothing is in it this is done by erasing and then creating the file If creat is successful it returns as its value a file descriptor that is a positive integer which is an index into a table of device and file control blocks Whenever a call is made to one of the unbuffered i o functions to access the file its file descriptor must be included in the function s parameters If creat fails it returns 1 and sets a code in the global integer errno If it succeeds errno is not modified The parameter name is a pointer to a character array containing the name of the file The drive identifier in the name is optional If its included the file will be created on the specified drive otherwise it will be created on the default drive The parameter pmode is optional if specified it is ignored The pmode parameter should be included how
86. ystems PAGE X 3 Aztec C86 Unbuffered 1 0 to be placed and an integer specifying the number of character to be read The read function reads characters directly into the caller s buffer The operation continues until read reads the number of characters specified by the caller It then returns as its value the number of characters read If read detects an error it returns as its value 1 and sets a code in the global integer errno h If no error was detected errno h is not modified The only symbolic value which read may set in errno is EBADF this means that an invalid file descriptor was passed to read The file errno h which can be included in the user s program defines the integer value of EBADF UNIX compatible I O to the stdin stdout and stderr devices As was mentioned in the section on console i o when a user s program is activated three logical devices are always open these are called stdin stdout and stderr By default these are associated with the system console however the operator can specify when activating the program that read operations directed to stdin and write operations directed to stdout be redirected to an operator specified device or disk file The user s program needn t be aware of the actual device associated with stdin stdout or stderr it simply issues read and write function calls as it would to the system console If the user s program is to communicate with stdin and stdout wh

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