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dice/StringFunctions dice/StringFunctions String Functions ---------------- Name : Description : Class =============+==============================================+======= atof : convert string into floating point : ANSI -------------+----------------------------------------------+------- atoi : convert string into integer : ANSI -------------+----------------------------------------------+------- atol : convert string into long integer : ANSI -------------+----------------------------------------------+------- isalnum : is character alphanumeric? : ANSI -------------+----------------------------------------------+------- isalpha : is character alphabetic? : ANSI -------------+----------------------------------------------+------- iscntrl : is character a control character? : ANSI -------------+----------------------------------------------+------- isdigit : is character numeric? : ANSI -------------+----------------------------------------------+------- isgraph : is character graphic? : ANSI -------------+----------------------------------------------+------- islower : is character lower case? : ANSI -------------+----------------------------------------------+------- isprint : is character printable? : ANSI -------------+----------------------------------------------+------- ispunct : is character punctuation? : ANSI -------------+----------------------------------------------+------- isspace : is character whitespace? : ANSI -------------+----------------------------------------------+------- isupper : is character upper case : ANSI -------------+----------------------------------------------+------- isxdigit : is character hex digit : ANSI -------------+----------------------------------------------+------- printf : format output : ANSI -------------+----------------------------------------------+------- stpchr : search for a character in a string : UNIX -------------+----------------------------------------------+------- stpcpy : string copy : UNIX -------------+----------------------------------------------+------- strbpl : build sting pointer : DICE -------------+----------------------------------------------+------- strcat : concatenate strings : ANSI -------------+----------------------------------------------+------- strchr : find character in string : ANSI -------------+----------------------------------------------+------- strcmp : compare strings : ANSI -------------+----------------------------------------------+------- strcpy : string copy : ANSI -------------+----------------------------------------------+------- strcspn : scan string for a character : ANSI -------------+----------------------------------------------+------- strdup : duplicate string : UNIX -------------+----------------------------------------------+------- strerror : return error string : ANSI -------------+----------------------------------------------+------- strftime : convert time to string : ANSI -------------+----------------------------------------------+------- stricmp : compare strings (case insensitive) : UNIX -------------+----------------------------------------------+------- strins : insert a string : DICE -------------+----------------------------------------------+------- strlen : return length of string : ANSI -------------+----------------------------------------------+------- strncat : concatenate strings : ANSI -------------+----------------------------------------------+------- strncmp : compare strings : ANSI -------------+----------------------------------------------+------- strncpy : string copy (length limited) : ANSI -------------+----------------------------------------------+------- strnicmp : compare strings (case insensitive, length : ANSI : limited) : -------------+----------------------------------------------+------- strpbrk : find break character in string : ANSI -------------+----------------------------------------------+------- strrchr : scan string for a character (backward) : ANSI -------------+----------------------------------------------+------- strspn : span of characters in string : ANSI -------------+----------------------------------------------+------- strstr : find sub-string in string : ANSI -------------+----------------------------------------------+------- strtod : convert string to double : ANSI -------------+----------------------------------------------+------- strtok : tokenize a string : ANSI -------------+----------------------------------------------+------- strtol, : convert string to [unsigned] long : ANSI strtoul : : -------------+----------------------------------------------+------- tolower : convert character to lower case : ANSI -------------+----------------------------------------------+------- toupper : convert character to upper case : ANSI -------------+----------------------------------------------+------- dice/IOFunctions,InputFunctions,OutputFunctions dice/IO Input/Output Functions ---------------------- Name : Description : Class =========+============================================+========== access : determine if file is accessible : UNIX ---------+--------------------------------------------+---------- chdir : change current directory : UNIX ---------+--------------------------------------------+---------- clearerr : clear error associated with file pointer : ANSI ---------+--------------------------------------------+---------- close : close a file descriptor : UNIX ---------+--------------------------------------------+---------- creat : create a file (obsolete) : UNIX ---------+--------------------------------------------+---------- dir : directory scanning routine : UNIX ---------+--------------------------------------------+---------- fclose : close a file pointer : ANSI ---------+--------------------------------------------+---------- fcntl : file control of a file : UNIX ---------+--------------------------------------------+---------- fdopen : associate file pointer and file descriptor : UNIX ---------+--------------------------------------------+---------- fdtoh : return file handle from file descriptor : AmigaDOS ---------+--------------------------------------------+---------- feof : return EOF indication for file : ANSI ---------+--------------------------------------------+---------- ferror : return error condition for file : ANSI ---------+--------------------------------------------+---------- fflush : flush buffers to file : ANSI ---------+--------------------------------------------+---------- fgetc : get a single character from a file : ANSI ---------+--------------------------------------------+---------- fgetpos : get current file position : ANSI ---------+--------------------------------------------+---------- fgets : get a line from a file : ANSI ---------+--------------------------------------------+---------- fhprintf : formatted printing to a file : AmigaDOS ---------+--------------------------------------------+---------- fileno : get file descriptor from file pointer : UNIX ---------+--------------------------------------------+---------- fopen : open a file : ANSI ---------+--------------------------------------------+---------- fprintf : formatted output to a file : ANSI ---------+--------------------------------------------+---------- fputc : write a single character to a file : ANSI ---------+--------------------------------------------+---------- fputs : write a string to a file : ANSI ---------+--------------------------------------------+---------- fread : read from a file pointer : ANSI ---------+--------------------------------------------+---------- freopen : reopen a file : ANSI ---------+--------------------------------------------+---------- fscanf : formatted input from a file : ANSI ---------+--------------------------------------------+---------- fseek : seek within a file : ANSI ---------+--------------------------------------------+---------- fsetpos : set position within a file : ANSI ---------+--------------------------------------------+---------- fstat : stat of a file : UNIX ---------+--------------------------------------------+---------- ftell : get file position : ANSI ---------+--------------------------------------------+---------- fwrite : write data to a file : ANSI ---------+--------------------------------------------+---------- getc : get a single character from a file : ANSI ---------+--------------------------------------------+---------- getchar : get a character from stdin : ANSI ---------+--------------------------------------------+---------- getcwd : get current working directory : UNIX ---------+--------------------------------------------+---------- getfnl : get file name list : DICE ---------+--------------------------------------------+---------- gets : get a line from stdin : ANSI ---------+--------------------------------------------+---------- ioctl : execute ioctl on file descriptor : UNIX ---------+--------------------------------------------+---------- isatty : is a file descriptor a TTY : UNIX ---------+--------------------------------------------+---------- lseek : seek in a file : UNIX ---------+--------------------------------------------+---------- mkdir : create a directory : UNIX ---------+--------------------------------------------+---------- open : open a file : UNIX ---------+--------------------------------------------+---------- perror : print error message : ANSI ---------+--------------------------------------------+---------- printf : formatted printing to standard out : ANSI ---------+--------------------------------------------+---------- putc : write a single character to a file : ANSI ---------+--------------------------------------------+---------- putchar : output character to stdout : ANSI ---------+--------------------------------------------+---------- puts : write a string to a file : ANSI ---------+--------------------------------------------+---------- read : read data from a file : UNIX ---------+--------------------------------------------+---------- remove : delete a file : ANSI ---------+--------------------------------------------+---------- rename : rename a file : ANSI ---------+--------------------------------------------+---------- rewind : seek to file beginning : ANSI ---------+--------------------------------------------+---------- rmdir : delete a directory : UNIX ---------+--------------------------------------------+---------- scanf : formatted input from input : ANSI ---------+--------------------------------------------+---------- setvbuf : change file buffering : ANSI ---------+--------------------------------------------+---------- sprintf : formatted printing to a string : ANSI ---------+--------------------------------------------+---------- sscanf : formatted input from a string : ANSI ---------+--------------------------------------------+---------- stat : stat a file by name : UNIX ---------+--------------------------------------------+---------- tmpfile : create a temporary file : ANSI ---------+--------------------------------------------+---------- tmpnam : create a unique temporary file name : ANSI ---------+--------------------------------------------+---------- ungetc : push character back to input stream : ANSI ---------+--------------------------------------------+---------- unlink : delete a file : UNIX ---------+--------------------------------------------+---------- write : write to a file : UNIX ---------+--------------------------------------------+---------- dice/MathFunctions dice/MathFunctions Math Functions -------------- Name : Description : Class =======+===================================+======= abs : take absolute value of an int : ANSI -------+-----------------------------------+------- acos : take arc cosine : ANSI -------+-----------------------------------+------- asin : take arc sine of a double : ANSI -------+-----------------------------------+------- atan : take arc tangent of a double : ANSI -------+-----------------------------------+------- cos : take cosine of a double : ANSI -------+-----------------------------------+------- _divs : signed long divide : DICE -------+-----------------------------------+------- _divu : unsigned long divide : DICE -------+-----------------------------------+------- exp : return e to the exponent : ANSI -------+-----------------------------------+------- fabs : take absolute value : ANSI -------+-----------------------------------+------- facos : take floating point arc cosine : UNIX -------+-----------------------------------+------- fasin : take floating point arc sine : UNIX -------+-----------------------------------+------- fatan : take floating point arc tangent : UNIX -------+-----------------------------------+------- fcos : take floating point cosine : UNIX -------+-----------------------------------+------- fexp : floating point exponent : UNIX -------+-----------------------------------+------- ffabs : return absolute value of float : UNIX -------+-----------------------------------+------- flog : take log of a float : UNIX -------+-----------------------------------+------- flog10 : take log of a float (base 10) : UNIX -------+-----------------------------------+------- fpow : return float to power of another : UNIX -------+-----------------------------------+------- fsin : return sine of a float : UNIX -------+-----------------------------------+------- fsqrt : return square root of a float : UNIX -------+-----------------------------------+------- ftan : return tan of a float : UNIX -------+-----------------------------------+------- labs : take absolute value of a long : ANSI -------+-----------------------------------+------- log : take log of a double : ANSI -------+-----------------------------------+------- log10 : take log of a double (base 10) : ANSI -------+-----------------------------------+------- _mods : signed long modulus : DICE -------+-----------------------------------+------- _modu : unsigned long modulus : DICE -------+-----------------------------------+------- _muls : unsigned long multiply : DICE -------+-----------------------------------+------- _mulu : unsigned long multiply : DICE -------+-----------------------------------+------- pow : return number to power of another : ANSI -------+-----------------------------------+------- rand : generate random number : ANSI -------+-----------------------------------+------- sin : return sine of a double : ANSI -------+-----------------------------------+------- sqrt : return square root of a double : ANSI -------+-----------------------------------+------- srand : set seed for random number : ANSI -------+-----------------------------------+------- tan : return tangent of a double : ANSI -------+-----------------------------------+------- dice/MiscFunctions,Miscellaneous dice/MiscFunctions Miscellaneous Functions ----------------------- Name : Description : Class =========================+================================+========== abort : abort a program : ANSI -------------------------+--------------------------------+---------- asctime : convert time into text : ANSI -------------------------+--------------------------------+---------- assert : assert that an expression is : ANSI : true : -------------------------+--------------------------------+---------- atexit : specify routine to call on : ANSI : exit : -------------------------+--------------------------------+---------- chkabort : check for ^C : AmigaDOS -------------------------+--------------------------------+---------- clock : return system clock time : ANSI -------------------------+--------------------------------+---------- CreateDiceRexxPort : create an application ARexx : DICE : port : -------------------------+--------------------------------+---------- CreateGlobalDiceRexxPort : create a global ARexx port : DICE -------------------------+--------------------------------+---------- ctime : convert time into text : ANSI -------------------------+--------------------------------+---------- DeleteDiceRexxPort : delete a DICE ARexx port : DICE -------------------------+--------------------------------+---------- DoRexxCommand : Parse an incomming ARexx : DICE : command : -------------------------+--------------------------------+---------- exit : exit from a program : ANSI -------------------------+--------------------------------+---------- _exit : exit from a program : DICE -------------------------+--------------------------------+---------- expand_args : expand command line (very : DICE : useful!) : -------------------------+--------------------------------+---------- getenv : get environment variable : ANSI -------------------------+--------------------------------+---------- GetDiceRexxPortSlot : Determine an application ARexx : DICE : slot : -------------------------+--------------------------------+---------- GetHead : get first element in EXEC list : DICE -------------------------+--------------------------------+---------- GetPred : get preceding element in EXEC : DICE : list : -------------------------+--------------------------------+---------- GetSucc : get succeeding element in EXEC : DICE : list : -------------------------+--------------------------------+---------- GetTail : get last element in EXEC list : DICE -------------------------+--------------------------------+---------- localtime : unpack time : ANSI -------------------------+--------------------------------+---------- LockAddr : semaphore routine : DICE -------------------------+--------------------------------+---------- LockAddrB : semaphore routine : DICE -------------------------+--------------------------------+---------- longjmp : jump to a saved setjmp : ANSI -------------------------+--------------------------------+---------- main : main program entry point : ANSI -------------------------+--------------------------------+---------- _main : main program entry point : DICE -------------------------+--------------------------------+---------- onbreak : Set ^C function : DICE -------------------------+--------------------------------+---------- PlaceRexxCommand : Send a command to ARexx : DICE -------------------------+--------------------------------+---------- PlaceRexxCommandDirect : send an ARexx command to an : DICE : application : -------------------------+--------------------------------+---------- ProcessRexxCommands : Handle incomming ARexx : DICE : commands : -------------------------+--------------------------------+---------- qsort : sort an array : ANSI -------------------------+--------------------------------+---------- raise : raise a signal : ANSI -------------------------+--------------------------------+---------- rega4 : return contents of register A4 : DICE : (different from geta4!) : -------------------------+--------------------------------+---------- setbuf : select alternative stream : ANSI : buffering : -------------------------+--------------------------------+---------- setjmp : prepare for future long jmp : ANSI -------------------------+--------------------------------+---------- signal : establish event traps : ANSI -------------------------+--------------------------------+---------- sleep : sleep for a while : UNIX -------------------------+--------------------------------+---------- stack_abort : exit point for stack alloc : DICE : failure : -------------------------+--------------------------------+---------- system : call system command shell : ANSI -------------------------+--------------------------------+---------- time : get current time : ANSI -------------------------+--------------------------------+---------- TryLockAddr : semaphore routine : DICE -------------------------+--------------------------------+---------- TryLockAddrB : semaphore routine : DICE -------------------------+--------------------------------+---------- UnLockAddr : semaphore routine : DICE -------------------------+--------------------------------+---------- UnLockAddrB : semaphore routine : DICE -------------------------+--------------------------------+---------- wbmain : main program entry for : AmigaDos : WorkBench : -------------------------+--------------------------------+---------- dice/MemoryFunctions dice/MemoryFunctions Memory Functions ---------------- Name : Description : Class ========+================================+========== alloca : allocate memory from the stack : UNIX --------+--------------------------------+---------- bcmp : compare two memory buffers : UNIX --------+--------------------------------+---------- bcopy : copy memory : UNIX --------+--------------------------------+---------- bzero : zero memory : UNIX --------+--------------------------------+---------- calloc : allocate memory : ANSI --------+--------------------------------+---------- clrmem : zero memory : AmigaDOS --------+--------------------------------+---------- cmpmem : compare two memory buffers : UNIX --------+--------------------------------+---------- free : free allocated memory : ANSI --------+--------------------------------+---------- malloc : allocate memory : ANSI --------+--------------------------------+---------- memcmp : compare two memory buffers : ANSI --------+--------------------------------+---------- memcpy : copy memory : ANSI --------+--------------------------------+---------- memmove : move memory : ANSI --------+--------------------------------+---------- memset : set memory to value : ANSI --------+--------------------------------+---------- movmem : move memory : UNIX --------+--------------------------------+---------- realloc : reallocate memory : ANSI --------+--------------------------------+---------- setmem : set memory to value : UNIX --------+--------------------------------+---------- dice/AslBase,DiceCacheBase,DiskfontBase,DOSBase,FifoBase,GadToolsBase,IconBase,IntuitionBase,LayersBase,MathBase,MathIeeeDoubBasBase,MathIeeeDoubTransBase,MathIeeeSingBasBase,MathIeeeSingTransBase,MathTransBase,RexxSysBase,SysBase,TimerBase,TranslatorB se,UtilityBase AslBase, DiceCacheBase, DiskfontBase, DOSBase, FifoBase, GadToolsBase, IconBase, IntuitionBase, LayersBase, MathBase, MathIeeeDoubBasBase, MathIeeeDoubTransBase, MathIeeeSingBasBase, MathIeeeSingTransBase, MathTransBase, RexxSysBase, SysBase, TimerBase, TranslatorBase, UtilityBase FUNCTION DICE will automatically open libraries for you (DICE) DESCRIPTION With DICE you need not worry about opening or closing Amiga libraries. You don't have to deal with the mess and hassle of checking error returns from each open. If a function call to a library is used, the library base variable will be referenced. If you did not explicitly define the variable, DICE will insert it, along with code to open and close the library. For example, if the _IntuitionBase base variable is referenced (say, with extern) but not declared then _IntuitionBase will be automatically declared in auto.lib. Additionally, auto.lib adds routines to the autoinit and autoexit sequences that automatically open "intuition.library" before _main and close it after _exit. If the auto-open fails the program will be aborted before _main is ever called. The autoexit routine that closes the library first checks to see if the base variable is NULL and skips trying to close the library if so. EXAMPLE /* ** Example program which just calls an ** intuition.library function without ** bothering to open the library. */ main() { DisplayBeep( 0 ); } dice/abort dice/abort FUNCTION abort a program with an error (ANSI) SYNTAX #include <stdlib.h> void abort(void); DESCRIPTION abort aborts a program with a non-zero exit code. The default abort routine in c.lib does the equivalent of an exit(20);. Programmers may override the default abort routine with their own. RESULTS abort never returns SEE ALSO assert EXAMPLE #include <stdio.h> #include <stdlib.h> main(int ac, char**av) { if (ac == 1) { puts("Hey, I expected a parameter!"); abort(); } puts("Thanks!"); return(0); } dice/abs,labs dice/abs,labs FUNCTION take absolute value (ANSI) SYNTAX #include <stdio.h> #include <stdlib.h> int r = [l]abs(n); int n; DESCRIPTION abs takes the absolute value of an int; labs takes the absolute value of a long. Both return the absolute value of the specified integer. For example, r = n if n >= 0, r = -n (positive) if n < 0. Normally one would not use this call due to overhead, but it exists for compatibility. ## WARNING: The absolute value of 0x80000000 cannot be taken. ## 0x80000000 will be returned. || NOTE: UNDER DICE, sizeof(int) == sizeof(long) and these two || functions are thus identical. INPUTS int n; integer RESULTS int r; absolute value of integer EXAMPLE #include<stdio.h> #include <stdlib.h> main() { int n = -53; printf("The absolute value of %d is %d\n", n, abs(n)); sleep(1); printf("But its faster if you write a macro:\n"); #define abs(x) (((x) < 0) ? -(x) : (x)) sleep(1); printf("The absolute value of %d is %d\n", n, abs(n)); return(0); } dice/access dice/access FUNCTION determine whether file is accessible (UNIX) SYNTAX #include <stdio.h> int r = access(filename, mode); const char *filename; int mode; DESCRIPTION access returns 0 upon success, -1 if access with the requested modes was impossible. The filename serves as a pointer to the string of the filename we wish to check, and the modes are what we expect the file to be able to do. The modes may be one or more of the following OR'd together. 0 check for existence of file only 1 check execute permission for file 2 check write permission for file 4 check read permission for file INPUTS char *filename; file to check int mode; modes as specified above RESULTS int r; 0 if modes available, -1 if not SEE ALSO open, fopen EXAMPLE #include <stdio.h> main(int ac, char **av) { char *name; if (ac == 1) { puts("Expected a file name argument"); exit(1); } name = av[1]; if (access(name, 0) == 0) { puts("It exists"); if (access(name, 1) == 0) puts("It is executable"); if (access(name, 2) == 0) puts("I can write to it!"); if (access(name, 4) == 0) puts("I can even read from it!"); } else puts("Hmmm, that file does not exist"); } dice/acos dice/acos FUNCTION take arc cosine (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = acos(b); double b; DESCRIPTION acos returns the arc cosine of a double quantity. INPUTS double b; double floating point value RESULTS double a; result double floating point value SEE ALSO asin, atan, cos, exp, fabs, log, log10, pow, sin, sqrt, tan, facos, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = acos(0.25); printf("acos 0.25 = %lf\n", a); /* 1.318 */ } { /* less accuracy */ float a = facos(0.25); printf("acos 0.25 = %lf\n", (double)a); } return(0); } dice/alloca dice/alloca FUNCTION allocate memory from the stack (UNIX) SYNTAX #include <stdlib.h> void *ptr = alloca(long bytes); DESCRIPTION alloca comes from the UNIX world. It allocates memory off the stack for use within a procedure. The allocated memory is automatically freed when the subroutine returns. :: Beginner's Note: Do not use alloca if you can help it; alloca is :: not easily portable across machines. || NOTE: When a low stack condition arises, alloca will abort by || printing an error message and calling abort; alloca does not || currently try to allocate dynamic memory when it runs out of || stack. Some implementations of alloca use alloca(0) to free || allocated stack. This feature is not currently implemented in || DICE's alloca call. SEE ALSO setjmp, longjmp EXAMPLE #include <alloca.h> #include <stdio.h> main(int ac, char*av[]) { char *ptr; if (ac == 1) { puts("I need test string"); exit(1); } ptr = alloca(strlen(av[1]) + 8); sprintf(ptr, "FOO.%s", av[1]); puts(ptr); return(0); } dice/asctime dice/asctime FUNCTION convert broken down time into standard text (ANSI) SYNTAX #include <time.h> char *str = asctime(ts); const struct tm *ts; DESCRIPTION asctime converts a broken down time in the tm structure to an ASCII string and returns a pointer to that string. The time string format is: on Dec 8 01:53:33 1987\n\0 where \n stands for a newline character and \0 is a terminating NULL. The string is stored in a static buffer shared by both asctime and ctime and so will be overwritten whenever either function is called. INPUTS struct tm *ts; pointer to a broken down time structure RESULTS char *str; pointer to static string SEE ALSO time, localtime, asctime, strftime, ctime, clock EXAMPLE #include <stdio.h> #include <time.h> main() { time_t t = time(NULL); fputs(asctime(localtime(&t)), stdout); return(0); } dice/assert dice/assert FUNCTION assert that an expression is true, else abort (ANSI) SYNTAX #include <assert.h> assert(condition); /* MACRO */ DESCRIPTION assert checks the condition and if not true prints an error message indicating the source filename and line number that the assertion failed at, and then aborts. The DICE version of assert generates a single static string in assert.h for each module containing the file name. Multiple usages of assert refer to the same physical filename string. INPUTS expression; an expression which the macro negates. SEE ALSO abort EXAMPLE #include <assert.h> main(int ac, char **av) { assert(ac > 1); /* expect at least one argument! */ return(0); } dice/asin dice/asin FUNCTION take the arc sine of a double quantity (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = asin(b); double b; DESCRIPTION asin takes the arc sine of a floating point quantity. INPUTS double b; double floating point value RESULTS double a; result double floating point value SEE ALSO acos, cos, exp, fabs, log, log10, pow, sin, sqrt, tan facos, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = asin(0.25); printf("asin 0.25 = %lf\n", a); /* 0.2527 */ } { /* less accuracy */ float a = fasin(0.25); printf("asin 0.25 = %lf\n", (double)a); } return(0); } dice/atan dice/atan FUNCTION take arc tan of a double quantity (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = atan(b); double b; DESCRIPTION atan takes the arc tangent of a floating point quantity. INPUTS double b; double floating point value RESULTS double a; result double floating point value SEE ALSO acos, asin, cos, exp, fabs, log, log10, pow, sin, sqrt, tan facos, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = atan(0.25); printf("atan 0.25 = %lf\n", a); /* 0.245 */ } { /* less accuracy */ float a = fatan(0.25); printf("atan 0.25 = %lf\n", (double)a); } return(0); } dice/atexit dice/atexit FUNCTION specify routine that is automatically called on exit (ANSI) SYNTAX #include <stdio.h> #include <stdlib.h> int error = atexit(funcptr); void (*fptr)(void); DESCRIPTION The atexit routine adds a function to the list of functions called when the program exits. The atexit routine is called before stdio and file descriptors are closed down. This exit function is called whenever the program exits, even if main returns normally. atexit will return 0 on success, -1 on failure. Some systems limit the number of atexit functions one can add (DICE does not) so if you add more than one you should check the return value. INPUTS void (*fptr)(void); routine to add to exit call list, takes no arguments and returns nothing. RESULTS int error; 0 on success, -1 on failure. SEE ALSO onbreak EXAMPLE /* * Atexit is useful to free up resources that would * otherwise not be freed up by DICE. For example, any * thing AllocMem'd. The atexit function is called on * any exit ... return from main, call to exit, or ^C. * * Normally your atexit routine cannot make assumptions * as to what has been allocated and what has not since * exit can be called from anywhere in the program. */ #include <stdio.h> #include <stdlib.h> extern void *AllocMem(); void *MemPtr; long MemLen; void myexit(void) { if (MemPtr) /* only if it is allocated */ FreeMem(MemPtr, MemLen); MemPtr = NULL; } /* Now we can take a ^C anywhere... before we allocate, * after, or even after we free (note I am careful to set * MemPtr back to NULL!) */ main() { short i; atexit(myexit); for (i = 0; i < 50; ++i) printf("Before %d\t(%ld)\n", i, AvailMem(0) ); MemLen = 32; MemPtr = AllocMem(MemLen, 0); if (! MemPtr) { exit(20); } for (i = 0; i < 50; ++i) printf("During %d\t(%ld)\n", i, AvailMem(0) ); FreeMem(MemPtr, MemLen); MemPtr = NULL; /* Mark as freed */ for (i = 0; i < 50; ++i) printf("After %d\t(%ld)\n", i, AvailMem(0) ); return(0); } dice/atof dice/atof FUNCTION convert string into double floating point value (ANSI) SYNTAX #include <stdio.h> #include <stdlib.h> double d = atof(str); const char *str; DESCRIPTION atof converts a string into a double floating point value; it is equivalent to calling strtod(str, NULL). Please refer to strtod for more information. INPUTS char *str; string, like "1.234E-4"; RESULTS double d; double fp representation of string SEE ALSO strtod dice/atoi,atol dice/atoi,atol FUNCTION convert string into integer (ANSI) SYNTAX #include <stdio.h> #include <stdlib.h> int x =atoi(str); long y = atol(str); const char *str; DESCRIPTION atoi and atol convert a string of decimal integers into an integer. It skips initial white space, processes an optional negative sign ('-'), processes digits '0' - '9', and returns the integer. atoi and atol have been superseded by the strtol function which can handle numbers of any base. || NOTE: Under DICE, sizeof(int) == sizeof(long), and thus atoi and || atol are exactly the same. INPUTS char *str; string to convert to int RESULTS int x; integer result long y; integer result SEE ALSO strtol EXAMPLE #include <stdio.h> #include <stdlib.h> main() { int i = atoi(" \t\t -123"); printf("i = %d (-123?)\n", i); return(0); } dice/bcmp dice/bcmp FUNCTION compare two memory buffers (UNIX) SYNTAX #include <string.h> int r = bcmp(s1, s2, bytes) void *s1; void *s2; size_t bytes; DESCRIPTION bcmp compares two memory buffers. A byte by byte (unsigned) comparison is done. When a comparison fails and the byte in s1 is less than the byte in s2 then -1 is returned. If the byte in s1 is greater than the byte in s2 then 1 is returned. If the count is exhausted and all comparisons succeed then 0 is returned indicating the two buffers are the same. INPUTS void *s1; pointer to first buffer void *s2; pointer to second buffer size_t bytes; size of each buffer RESULTS int r; -1 if buf s1 < buf s2, 0 if buf s1 == buf s2, 1 if buf s1 > buf s2. SEE ALSO cmpmem, memcmp, strcmp EXAMPLE #include <stdlib.h> #include <assert.h> main() { unsigned char buf1[] = {5, 12, 13}; unsigned char buf2[] = {5, 12, 13}; int r; r = bcmp(buf1, buf2, 3); assert(r == 0); buf1[2] = 12; r = bcmp(buf1, buf2, 3); assert(r < 0); buf1[2] = 200; r = bcmp(buf1, buf2, 3); assert(r > 0); return(0); } dice/c.o dice/c.o FUNCTION DICE startup module for all C programs SYNTAX The module dlib:c.o is normally specified first in a link line, or automatically by dcc. DESCRIPTION C programs require a bit of code (called "glue") in order to start execution. This code saves machine registers, sets up global storage, parses arguments, open libraries and, after the program terminates, communicates results back to the host Operating System. For use with the Amiga, DICE includes a suitable startup module called c.o. This module is automatically include by dcc, and need not concern most programmers. The startup module performs the following tasks: 1) Save non-scratch registers. 2) If resident, allocate space for both DATA (Initialized globals) & BSS (Uninitialized globals - set to zero). Copy initialized data into the allocated space. Clear the BSS portion of the data space. If the BSS has already been allocated by the load module but not cleared, clear the BSS portion of the data space. 3) Clear the ^C (Control C) signal 4) Setup _SysBase, the pointer to the Amiga's master library, Exec. 5) Call all AUTOINIT subroutines (this usually results in at least the dos.library being opened). 6) Call _main (usually the c.lib version, but you may override it). 7) Fall through to _exit(0). Note that while c.a falls through to _exit after calling _main, _main itself calls main with: exit(main(args...)); Thus, main() is always expected to return a valid value (i.e. not void). C.O. also handles the low-level _exit (__exit:) in the following sequence: 1) Call all AUTOEXEC subroutines (this normally closes the DOS library and other automatically opened libraries such as floating point). 2) Free all memory allocated by the task, including the small data segment & BSS space. Note that all variables we use hereafter have already been placed in registers since the dataspace is no longer valid. 3) If started from workbench, reply to the workbench message, _WBMsg. 4) Restore original registers and rts (exit back to the Operating System). c.o also exists in c.lib, however that version is not normally used. || NOTE: Normally the programmer does not override the startup object || file (c.o). However, in some cases a programmer will want to override _main, as in: _main(len, arg) int len; char *arg; {... } The _main entry point is passed the length and arg pointer unmodified from the OS. When you override _main you cannot call any stdio (fopen, fclose, puts, printf, etc...), any low level IO (open, close, read, write, etc...), or any C memory allocation routine (malloc, etc...). Normally _main will be overridden if the programmer wishes to save space, and makes only Amiga system calls (such as Open, Close, Read, Write, FindTask, etc.). Overriding the C.LIB generally makes executables much smaller because no extraneous stdio or low level IO routines are brought in from c.lib. Normally you exit out of _main by calling _exit(code) (note the underscore). dice/calloc dice/calloc FUNCTION allocate memory and clear (ANSI) SYNTAX #include <stdlib.h> void *ptr = calloc(objsize, numobjs) size_t objsize; size_t numobjs; DESCRIPTION Numobjs objects each objsize in size are allocated contiguously and a pointer to the first object is returned. The memory is cleared to 0. Effectively this is equivalent to malloc(objsize * numobjs), and then setmem(ptr, objsize * numobjs, 0) . calloc returns NULL if the memory cannot be allocated. INPUTS size_t objsize; size of each object size_t numobjs; number of objects to allocate RESULTS void *ptr; pointer to first object SEE ALSO malloc, strdup EXAMPLE /* * allocate 16 objects and fill with junk */ #include <stdlib.h> #include <assert.h> typedef struct { long a, b, c; } Junk; main() { Junk *jp; jp = calloc(sizeof(Junk), 16); assert(jp); { Junk *tj = jp; short i; for (i = 0; i < 16; ++i, ++tj) { tj->a = 1; tj->b = 2; tj->c = 3; } } free(jp); return(0); } dice/chdir dice/chdir FUNCTION change current directory (UNIX) SYNTAX #include <stdio.h> int r = chdir(path); const char *path; DESCRIPTION chdir changes the current directory to the specified path, returning 0 on success and -1 on failure. || NOTE: When a program exits, the original directory will be || restored. INPUTS char *path; path to chdir into RESULTS int r; return value, 0 if ok, -1 if error SEE ALSO getcwd EXAMPLE #include <stdio.h> char buf[512]; main(int ac, char **av) { getcwd(buf, sizeof(buf)); if (chdir("RAM:")) { puts("Couldn't chdir into RAM:"); exit(1); } FILE *fp; if (fp = fopen("yy", "w")) { fputs("Fight for vegetable rights!\n", fp); fclose(fp); puts("created file yy in RAM:"); } if (chdir(buf)) { printf("Unable to chdir back into %s\n", buf); } return(0); } dice/chkabort dice/chkabort FUNCTION Check for ^C and take the appropriate action (AmigaDOS) SYNTAX (void) chkabort(void); DESCRIPTION chkabort checks for a ^C and takes the appropriate action. If the appropriate action is to exit then this routine does not return. Stdio and other routines will call chkabort at various points. The action taken by ^C may be set by the signal or onbreak calls. SEE ALSO onbreak, atexit, signal EXAMPLE /* * wait for somebody to hit ^C (note that this is very * wasteful of CPU and thus isn't a real good example). */ main() { int i; for (i = 0; i < 10000000; ++i) chkabort(); return(0); } dice/clearerr dice/clearerr FUNCTION Clear error associated with a file pointer (ANSI) SYNTAX #include <stdio.h> void clearerr(fp); (MACRO) FILE *fp; DESCRIPTION The clearerr macro clears both the EOF flag and the ERROR flag associated with a file pointer. When an ERROR occurs on a file pointer, addition fread, fwrite, etc. calls will not work until the ERROR indicator is cleared. || NOTE: Refer to the file_pointer manual page for general || information. INPUTS FILE *fp; file pointer to clear the error on. RESULTS none; the error and EOF indicators are cleared SEE ALSO feof, ferror, rewind, fseek dice/clock dice/clock FUNCTION return system clock value (ANSI) SYNTAX #include <time.h> clock_t clk = clock(void); DESCRIPTION clock returns the system clock in ticks. To obtain seconds from ticks divide the returned value by CLK_TCK in <time.h>. INPUTS none RESULTS clock_t clk; system clock time value SEE ALSO time, localtime, asctime, strftime, ctime, clock EXAMPLE #include <stdio.h> #include <time.h> main() { clock_t clk = clock(); long i; clk = clk + CLK_TCK; for (i = 0; clk - clock() > 0; ++i) ; printf("The FOR loop calling clock() took\ %d loops in one second\n", i); return(0); } dice/close dice/close FUNCTION close a file descriptor (UNIX) SYNTAX #include <fcntl.h> int r = close(fd); int fd; DESCRIPTION close closes a file descriptor. If an error occurs or the descriptor is invalid, a non-zero return code will result and errno will be set to the appropriate error condition. || NOTE: Refer to the file_descriptor manual page for general || information. Unlike file pointers and file handles, the file || descriptor is checked for validity and if illegal, an error will || be returned. INPUTS int fd; file descriptor to close, the file descriptor becomes invalid after this call RESULTS int r; return value, 0 == ok, non-zero == error SEE ALSO creat, fcntl, fdtofh, ioctl, isatty, lseek, mkdir, open, read, rmdir, unlink, write See open for an example dice/cmpmem dice/cmpmem FUNCTION compare two memory buffers (UNIX) SYNTAX #include <string.h> int r = cmpmem(s1, s2, bytes) void *s1; void *s2; size_t bytes; DESCRIPTION Like bcmp, this function compares two memory buffers. A byte by byte (unsigned) comparison is done. When a comparison fails and the byte in s1 is less than the byte in s2 then -1 is returned. If the byte in s1 is greater than the byte in s2 then 1 is returned. If the count is exhausted and all comparisons succeed then 0 is returned indicating the two buffers are the same. INPUTS void *s1; pointer to first buffer void *s2; pointer to second buffer size_t bytes; size of each buffer RESULTS int r; -1 if buf s1 < buf s2, 0 if buf s1 == buf s2, 1 if buf s1 > buf s2. SEE ALSO bcmp, memcmp EXAMPLE #include <stdlib.h> #include <assert.h> main() { unsigned char buf1[] = {3, 5, 7, 11, 13}; unsigned char buf2[] = {3, 5, 7, 11, 13}; int r; r = cmpmem(buf1, buf2, 5); assert(r == 0); buf1[2] = 2; r = cmpmem(buf1, buf2, 5); assert(r < 0); buf1[2] = 200; r = cmpmem(buf1, buf2, 5); assert(r > 0); return(0); } dice/cos,fcos dice/cos,fcos FUNCTION cos: return cosine of a double (ANSI) fcos: return cosine of a float (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = cos(b); double c; float c = fcos(d); double d; DESCRIPTION cos returns the cosine of a type double quantity. fcos is the same, except expects a type float. These functions use radian measure. INPUTS double b; double floating point value RESULTS double a; result double floating point value SEE ALSO acos, asin, atan, exp, fabs, log, log10, pow, sin, sqrt, tan facos, fasin, fcos EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = cos(0.25); printf("cos 0.25 = %lf\n", a); /* 0.9689 */ } { /* less accuracy */ float a = fcos(0.25); printf("cos 0.25 = %lf\n", (double)a); } return(0); } dice/creat dice/creat FUNCTION create a file (UNIX) SYNTAX #include <fnctl.h> int fd = creat(file); char *file; DESCRIPTION creat creates a new file and returns a file descriptor for it. This call is equivalent to open(file,O_CREAT|O_TRUNC|O_RDWR); this is an obsolete function and should not be used. dice/CreateDiceRexxPort dice/CreateDiceRexxPort FUNCTION Create an application ARexx port (DICE) SYNTAX #include <lib/rexx.h> short r = CreateDiceRexxPort(port, name) struct MsgPort *port; char *name; DESCRIPTION This call integrates any number of ARexx ports beyond the master port into DICE's ARexx system. This call may be made from any point in your program. After this call returns the message port will accept incomming ARexx messages. || NOTE: For simple programs you can simply use the master port || (RexxPort) that DICE sets up for you automatically and need not || bother with creating additional ports. This call is more of use || in more complex programs which handle multiple projects || simultaniously. If you had declared RexxHostName as NULL causing DICE to not initialize an internal default RexxPort, you can pass NULL for port to initialize DICE's internal default RexxPort, thereby allowing PlaceRexxCommand() calls that specify a NULL port (i.e. to use DICE's internal default RexxPort). You are not required to use DICE's internal message port, it is simply convenient. INPUTS struct MsgPort *port; A blank msgPort structure (that is, totally zero'd out). DICE will fill the structure with appropriate values. DICE uses the same signal bit as it allocated for the master port (RexxPort). DICE makes this message port public through the AddPort() call. char *name A pointer to the name of the message port. DICE adds a .NN extension to this name, finding a free slot number when creating a public message port. If you pass NULL for this field, DICE will create a private message port suitable for handling ARexx call-backs. An error (-1) is returned if no slots are available (all 99 are in use). If you had passed NULL for the port structure then DICED will initialize RexxHostName to the extended name. RESULTS int r; the slot number for the port or -1 if an error occured. SEE ALSO CreateGlobalDiceRexxPort, DeleteDiceRexxPort, GetDiceRexxPortSlot EXAMPLE See DICE ARexx Support in chapter dice/CreateGlobalDiceRexxPort dice/CreateGlobalDiceRexxPort FUNCTION Create a global ARexx port (DICE) SYNTAX #include <lib/rexx.h> rc = CreateGlobalDiceRexxPort(port, name) int rc; struct MsgPort *port; char *name; DESCRIPTION CreateGlobalDiceRexxPort integrates any number of ARexx ports beyond the master port into DICE's ARexx system. This call may be made from any point in your program. After this call returns the message port will accept incomming ARexx messages. || NOTE: For simple programs you can simply use the master port || (RexxPort) that DICE sets up for you automatically and need not || bother with creating additional ports. This call is more of use || in more complex programs which handle multiple projects || simultaniously. If you had declared RexxHostName as NULL causing DICE to not initialize an internal default RexxPort, you can pass NULL for msgPort to initialize DICE's internal default RexxPort, thereby allowing PlaceRexxCommand calls that specify a NULL port (i.e. to use DICE's internal default RexxPort). You are not required to use DICE's internal message port, it is simply convenient. INPUTS struct MsgPort *port; A blank msgPort structure (that is, totally zero'd out). DICE will fill the structure with appropriate values. DICE uses the same signal bit as it allocated for the master port (RexxPort). DICE will make this message port public through the AddPort() call. char *name; A pointer to the name of the message port. DICE uses this name verbatim. An error (-1) is returned if the port already exists. If you had passed NULL for the MsgPort structure DICE will initialize RexxHostName to name. RESULTS int r; 0 for success, -1 for error SEE ALSO CreateDiceRexxPort, DeleteDiceRexxPort, GetDiceRexxPortSlot EXAMPLE See DICE ARexx Support in chapter dice/ctime dice/ctime FUNCTION convert time into standard text (ANSI) SYNTAX #include <time.h> char *str = ctime(&t); time_t t; DESCRIPTION ctime converts a time pointer into ASCII text using the following format: Sun Dec 8 01:53:33 1987\n\0 where \n stands for a newline character and \0 is terminating nul. The string is stored in a static buffer shared by both asctime and ctime and so will be overwritten whenever either function is called. INPUTS time_t *t; pointer to a time_t value RESULTS char *str; pointer to static string SEE ALSO time, localtime, asctime, strftime, ctime, clock EXAMPLE #include <stdio.h> #include <time.h> main() { time_t t = time(NULL); fputs(ctime(&t), stdout); return(0); } dice/DeleteDiceRexxPort dice/DeleteDiceRexxPort FUNCTION Delete a DICE ARexx port (DICE) SYNTAX #include <lib/rexx.h> void DeleteDiceRexxPort(port) struct MsgPort *port; DESCRIPTION This call deletes a previously created DICE ARexx port. You may NOT delete any ARexx port while within DoRexxCommand(). This call may only be made from the top level of your program or you run the risk of deleted an ARexx port out from under yourself. ## WARNING: You may NOT delete the master ARexx port, only those you ## specifically create. This call automatically clears out any as yet unread messages on the port, removes the port from the public message list with RemPort(), and zero's the structure. INPUTS struct MsgPort *port; The message port to delete. You must have created it using CreateGlobalDiceRexxPort or CreateDiceRexxPort SEE ALSO CreateGlobalDiceRexxPort, CreateDiceRexxPort, GetDiceRexxPortSlot EXAMPLE See DICE ARexx Support in chapter dice/dir dice/dir FUNCTION disk directory scanning (UNIX) SYNTAX #include <sys/dir.h> DIR *dirhan = opendir(path); struct direct *entry = readdir(dirhan); (void) rewinddir(dirhan); void closedir(dirhan); const char *path; DIR *dirhan; DESCRIPTION These are UNIX compatible directory scanning calls. After opening a directory with opendir, you may scan it with successive calls to readdir until NULL is returned, then either rewinddir it for a rescan, or closedir it when done. The DIR structure is private to the library. Valid fields within struct direct are d_name (the file name), and d_namlen (the length of the file name, not usually needed). You can chdir into the directory and stat each entry to obtain additional information. Note that while the UNIX directory scanning routines will not be as efficient as the Amiga directory scanning routines, the UNIX directory scanning routines are portable. || NOTE: Unlike the Amiga directory scanning routines that use Amiga || File Locks, these calls will automatically deallocate resources if || the program terminates. rewinddir's prototype returns an int. || This is for internal use only. You should never use rewinddir's || return value yourself. SEE ALSO chdir EXAMPLE #include <stdio.h> #include <sys/dir.h> main(int ac, char*av[]) { DIR *dir; if (ac == 1) { puts("test dir"); exit(1); } if (dir = opendir(av[1])) { struct direct *entry; while (entry = readdir(dir)) { printf("%s\n", entry->d_name); } closedir(dir); } return(0); } dice/_divs,_divu dice/_divs,_divu FUNCTION Signed and unsigned long divide (DICE) DESCRIPTION DICE uses these assembly level functions whenever it needs to do long division; they are not callable from C. INPUTS D0 32 bit signed/unsigned integer D1 32 bit signed/unsigned integer RESULTS D0 D0 divided by D1 SEE ALSO _mods, _modu, _muls, _mulu dice/DoRexxCommand dice/DoRexxCommand FUNCTION Parse an incomming ARexx command (DICE) SYNTAX #include <lib/rexx.h> /* YOU DECLARE THIS IN YOUR CODE */ long DoRexxCommand(msg, port, arg0, pres) void *msg; struct MsgPort *port; char *arg0; char **pres; { long rc = 0; *pres = "return string"; return(rc); } DESCRIPTION DoRexxCommand is a routine that YOU supply to process incomming ARexx requests. DICE will call your routine for any requests it processes with ProcessRexxCommands as well as for any requests that come in during processing of a PlaceRexxCommand. DICE presets pres to NULL. To return an error simply return a non-zero error code. To return a string, set pres to point to the string and return 0. DICE will make a copy of the string to return to ARexx. Note that the application requesting the string will not see if if they have not requested 'OPTIONS RESULTS' as part of their processing. ## WARNING: Because your procedure must return before DICE can ## process the string, you MUST not assign pres to any local stack ## variables. The resulting crash can be quite spectacular. INPUTS void *msg; Incomming ARexx message if necessary. struct MsgPort *port; Port that the message came in on. char *arg0; The ARexx command that is to be processed. Your code must parse this in whatever way you want. char **pres; Place to store result string. RESULTS int rc; Return code to be passed to the application requesting the ARexx command. SEE ALSO PlaceRexxCommand, PlaceRexxCommandDirect, ProcessRexxCommands EXAMPLE See DICE ARexx Support in chapter dice/exit dice/exit FUNCTION Exit from a program 'nicely' (ANSI) SYNTAX #include <stdlib.h> (void) exit(code) DESCRIPTION exit exits the program and returns the specified exit code. Normally you pass 0 to indicate no errors, and a positive number to indicate a program error to the parent. exit closes all stdio file pointers, low level file descriptors, perhaps a few other things, and then finally calls _exit with the code. If you use main you should call exit to exit the program or return an error code from main. If you use the _main entry point (only for programmers dead set on optimizing executable size and using only system library calls) you should use the _exit exit point. SEE ALSO main, _main, _exit EXAMPLE main(int ac, char *av[]) { if (ac <= 1) { puts("Sorry, you must supply a parameter!"); exit(1); } puts("Thanks!"); exit(0); } dice/_exit dice/_exit FUNCTION exit from a program without bothering to release resources (ANSI) SYNTAX #include <stdlib.h> (void) _exit(code) int code; DESCRIPTION _exit exits from a program and returns the specified exit code. Normally you pass 0 to indicate no errors, a positive number to indicate a program error to the parent. Note that since auto-init opened libraries are closed in the startup module (c.o), automatically opened libraries will be automatically closed for you. However, any libraries you manually declare the library base variable for and manually open must be closed by you. You should only call _exit if you used the _main entry point (instead of the usual main), and then only after releasing all resources (such as file handles opened with open). INPUTS int code; code is a value that is passed back to caller SEE ALSO main, _main, exit EXAMPLE _main() { Write(Output(), "Ouch!!\n", 7); _exit(20); /* 20 - Severe Error */ } dice/exp dice/exp FUNCTION return e to the power of the double quantity (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = exp(b); double b; DESCRIPTION exp returns e to the power of the floating point quantity. INPUTS double b; double floating point value RESULTS double a; result double floating point value SEE ALSO acos, asin, atan, cos, fabs, log, log10, pow, sin, sqrt, tan facos, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = exp(0.25); printf("exp 0.25 = %lf\n", a); } { /* less accuracy */ float a = fexp(0.25); printf("exp 0.25 = %lf\n", (double)a); } return(0); } dice/expand_args dice/expand_args FUNCTION expand command line argument wildcards (DICE) SYNTAX #include <stdio.h> int error = expand_args(xac, xav, &ac, &av); int xac; const char **xav; int ac; char **av; DESCRIPTION expand_args is a powerful and convenient function. A few lines of simple code allow your program to have full wildcard support under any version of the OS. expand_args takes an argc/argv list and expands any wildcard arguments by scanning the appropriate directory. It malloc's however much memory it needs to create the new list and ignores xav[0] (that is, it just copies it to the returned av[0] without doing a wildcard expansion). expand_args fills in the ac and av variables with its own malloc'd version of the argument list, now completely expanded. There is no limit to the number of files that may be in this result list (you could conceivably have thousands). expand_args may be used to expand arbitrary AmigaDOS wildcards and is not limited to an anchored search. For example, you could specify: sys:#?/#? in which case a list of a second level files/dirs will be generated. In the above case, expand_args scans sys, then scans any sub directories found in sys. Generic AmigaDOS wildcarding is used and incredibly complex wildcards may be specified. Please note, however, that any wildcard elements containing #? in combination with other elements (such as (a|b|c)) will cause huge amounts of stack to be used and also quite a bit of memory during the scan. expand_args limits itself to 4K of stack before giving up. Any program that uses expand_args should be run with at least 8K of stack. INPUTS int xac; original argc char **xav; original argv int *ac; pointer to new argc char ***av; pointer to new argv RESULTS int error; 0 if all went well, non-zero otherwise EXAMPLE #include <stdio.h> main(int xac, char **xav) { int ac, i, error; char **av; int error = expand_args(xac, xav, &ac, &av); for (i = 1; i < ac; ++i) { printf("%s\n", av[i]); } } /* expand_args #?.c */ dice/fabs dice/fabs FUNCTION return the absolute value of a double quantity (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = fabs(b); double b; DESCRIPTION fabs returns the absolute value of a floating point quantity. INPUTS float d; float floating point value RESULTS int arg; control argument int r; result, error if less than 0. EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = fabs(-0.25); printf("fabs -0.25 = %lf\n", a); /* 0.25 */ } { /* less accuracy */ float a = ffabs(-0.25); printf("fabs -0.25 = %lf\n", (double)a); } return(0); } dice/facos dice/facos FUNCTON float arc cosine (UNIX) LIBRARY m.lib SYNTAX #include <math.h> float c = facos(d); float d; DESCRIPTION facos returns the arc cosine of a floating point quantity. INPUTS float d; float floating point value RESULTS result float; floating point value SEE ALSO acos, asin, atan, cos, exp, fabs, log, log10, pow, sin, sqrt, tan, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = acos(0.25); printf("acos 0.25 = %lf\n", a); /* 1.318 */ } { /* less accuracy */ float a = facos(0.25); printf("acos 0.25 = %lf\n", (double)a); } return(0); } dice/fasin dice/fasin FUNCTION return arc sine of a float quantity (UNIX) LIBRARY m.lib SYNTAX #include <math.h> float c = fasin(d); float d; DESCRIPTION fasin returns the arc sine of a floating point quantity. INPUTS float d; float floating point value RESULTS float c; result float floating point value SEE ALSO acos, asin, atan, cos, exp, fabs, log, log10, pow, sin, sqrt, tan facos EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = asin(0.25); printf("asin 0.25 = %lf\n", a); /* 0.2527 */ } { /* less accuracy */ float a = fasin(0.25); printf("asin 0.25 = %lf\n", (double)a); } return(0); } dice/fatan dice/fatan FUNCTION return arc tan of a float quantity (UNIX) LIBRARY m.lib SYNTAX #include <math.h> float c = fatan(d); float d; DESCRIPTION fatan returns the arc tan of a floating point quantity. INPUTS float d; float floating point value RESULTS float c; result float floating point value SEE ALSO acos, asin, atan, cos, exp, fabs, log, log10, pow, sin, sqrt, tan facos, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = atan(0.25); printf("atan 0.25 = %lf\n", a); /* 0.245 */ } { /* less accuracy */ float a = fatan(0.25); printf("atan 0.25 = %lf\n", (double)a); } return(0); } dice/fclose dice/fclose FUNCTION close a file pointer (ANSI) SYNTAX #include <stdio.h> int error = fclose(fp); FILE *fp; DESCRIPTION fclose flushes any data remaining in the file pointer's output buffer to the file and then closes the file. The file pointer is no longer valid. fclose returns any error condition that occurred while it was flushing the buffered data to the file. The file is closed even if an error occurred. || NOTE: You can fclose(stdin), fclose(stdout), and fclose(stderr) to || save space or detach your process from the console (i.e. allow the || console window to be closed). ## WARNING: If you fclose stdin, stdout, and stderr with the ## intention of removing all references to the console window, you ## must put a NULL in your processes pr_ConsoleTask field. Otherwise, ## the console window will be able to close, but your process will ## still have a reference to the now non-existent window. Refer to ## the file_pointer manual page for general information INPUTS FILE *F; file pointer RESULTS int error; error on fclose, or 0 if none SEE ALSO fopen, fread, fwrite, fgets, fputs dice/fcntl dice/fcntl FUNCTION file control on a file (UNIX) SYNTAX #include <fcntl.h> int r = fcntl(fd, req, arg) int fd; int req; int arg; DESCRIPTION fcntl may be used to control various aspects of an fd and is a higher level call than ioctl. Currently, nothing truly significant can be accomplished by a fcntl call for files. However, fcntl fully supports programmer simulated file descriptors. || NOTE: Refer to the file_descriptor manual page for general || information Unlike file pointers and file handles, the file || descriptor is checked for validity and if illegal, an error will || be returned. INPUTS int fd; file descriptor to operate on int req; request from <fcntl.h> (F_* defines) int arg; control argument RESULTS int r; result, error if less than 0 SEE ALSO close, creat, fcntl, fdtofh, ioctl, isatty, lseek, mkdir, open, read, rmdir, unlink, write dice/fdopen dice/fdopen FUNCTION associate a file pointer with an open file descriptor (UNIX) SYNTAX #include <stdio.h> FILE *fp = fdopen(fd, modes); int fd; char *modes; DESCRIPTION fdopen associates an open file descriptor with a file pointer. || NOTE: Once fclose is used, the file pointer will also close the || file descriptor. Refer to the fopen manual page for a description || of available modes. Also, when you use fdopen the file will not be || truncated and if you specify mode a for append, the file || descriptor must have been opened with the O_APPEND flag. That is, || the mode string should be similar to the open flags that were used || to open the file descriptor. Refer to the file_pointer manual page || for general information INPUTS int fd; file descriptor to associated with a new file pointer char *modes; modes string, such as "r+". RESULTS FILE *fp; new file pointer or NULL if an error occurred SEE ALSO fopen, fread, fwrite, fgets, fputs dice/fdtofh dice/fdtofh FUNCTION return AmigaDOS file handle for file descriptor (AmigaDOS) SYNTAX #include <stdio.h> BPTR fh = fdtofh(fd); int fd; DESCRIPTION fdtofh returns the AmigaDOS file handle associated with a file descriptor or NULL if the file descriptor is illegal or simulated. You may then make AmigaDOS library calls using the file handle. INPUTS int fd; file descriptor RESULTS BPTR fh; associated file handle or NULL SEE ALSO close, creat, fcntl, ioctl, isatty, lseek, mkdir, open, read, rmdir, unlink, write EXAMPLE #include <stdio.h> main() { FILE * fh; write(1, "Quayle\n", 6); if( fh = fdtofh(1) ) /* Example Only! */ Write(fh, "Bait\n", 6); return(0); } dice/feof dice/feof FUNCTION test a file pointer for End Of File (ANSI) SYNTAX #include <stdio.h> int r = feof(fp); (MACRO) FILE *fp; DESCRIPTION feof returns the EOF status of a file pointer. The status is not changed by this macro. 0 is returned if no EOF condition exists, non-zero if an EOF condition exists (not necessarily 1 or -1, just non-zero). Use clearerr to clear the EOF condition. Note than fseek and rewind also clear an EOF condition. INPUTS FILE *fp; file pointer RESULTS int r; 0 if no EOF condition exists, != 0 if an EOF condition exists (not necessarily 1 or -1). SEE ALSO fopen, fclose, fread, fwrite, fgets, fputs, file_pointer dice/ferror dice/ferror FUNCTION return ERROR condition for file pointer (ANSI) SYNTAX #include <stdio.h> int r = ferror(fp); /* MACRO */ FILE *fp; DESCRIPTION ferror returns the ERROR status of a file pointer. The status is not changed by this macro. 0 is returned if no ERROR condition exists, non-zero if an ERROR condition exists (not necessarily 1 or -1, just non-zero). INPUTS FILE *fp; file pointer RESULTS int r; 0 if no ERROR condition exists, != 0 if an ERROR condition exists (not necessarily 1 or -1). SEE ALSO fopen, fclose, fread, fwrite, fgets, fputs, file_pointer dice/fexp dice/fexp FUNCTION return e to the power of the float quantity (UNIX) LIBRARY m.lib SYNTAX #include <math.h> float c = fexp(d); float d; DESCRIPTION fexp returns e to the power of the floating point quantity INPUTS float d; float floating point value RESULTS float c; result float floating point value SEE ALSO acos, asin, atan, cos, exp, fabs, log, log10, pow, sin, sqrt, tan, facos, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = exp(0.25); printf("exp 0.25 = %lf\n", a); printf("exp 0 = %lf\n", (double)exp(0) ); } { /* less accuracy */ float a = fexp(0.25); printf("exp 0.25 = %lf\n", (double)a); } return(0); } dice/ffabs dice/ffabs FUNCTION return the absolute value of a float (UNIX) LIBRARY m.lib SYNTAX #include <math.h> float c = ffabs(d); float d; DESCRIPTION ffabs returns the absolute value of a floating point quantity. INPUTS float d; float floating point value RESULTS int arg; control argument int r; result, error if less than 0. SEE ALSO acos, asin, atan, cos, exp, fabs, log, log10, pow, sin, sqrt, tan, facos, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = fabs(-0.25); printf("fabs -0.25 = %lf\n", a); /* 0.25 */ } { /* less accuracy */ float a = ffabs(-0.25); printf("fabs -0.25 = %lf\n", (double)a); } return(0); } dice/fflush dice/fflush FUNCTION flush buffers to file (ANSI) SYNTAX #include <stdio.h> int error = fflush(fp); FILE *fp; DESCRIPTION fflush writes out any buffered data out to the file descriptor associated with the file pointer. Normally a file is either unbuffered, line buffered, or fully buffered; fflush is useful in the latter two cases as is shown by the example. The function will return -1 if a write error occurred, 0 if no error occurred. || NOTE: Refer to the file_pointer manual page for general || information. INPUTS FILE *fp; file pointer RESULTS int error; 0 if no error, -1 on error. SEE ALSO fopen, fclose, fread, fwrite, fgets, fputs EXAMPLE /* * Since text to stdout is normally line buffered, * if we do not write out a newline '\n' then the * line is still buffered in memory and we have to * fflush() to write it out. */ #include <stdio.h> main() { char buf[256]; printf("Enter a number -"); fflush(stdout); fgets(buf, sizeof(buf), stdin); printf("Munch Munch..."); fflush(stdout); sleep(1); puts("Thanks!"); } dice/fgetc,getc dice/fgetc,getc FUNCTION fgetc: get a single character (ANSI) getc: get a single character from a file pointer (ANSI) SYNTAX #include <stdio.h> int c = fgetc(fp); int c = getc(fp); /* MACRO */ FILE *fp; DESCRIPTION getc and fgetc both read a single character from a file pointer. The value returned is actually an int because EOF (-1) must be differentiated from a 255. Each returns an integer 0-255 or EOF (-1) if an end of file occurs. || NOTE: Refer to the file_pointer manual page for general || information. INPUTS FILE *fp; file pointer RESULTS int c; character 0 to 255, or EOF (-1). SEE ALSO putc, fputc, fread, fwrite EXAMPLE /* * copy stdin to stdout using getc/putc. Normally * one uses fread/fwrite, but I'll save that for the * fread manual page. * Note that I output the initial message to stderr so * it does not get stuck into stdout in case the user * has redirected stdout. */ #include <stdio.h> main() { int c; fputs("Type a couple of lines, then ^\\ (EOF)\n", stderr); while ((c = getc(stdin)) != EOF) { putc(c, stdout); } return(0); } dice/fgetpos dice/fgetpos FUNCTION get current file position (ANSI) SYNTAX #include <stdio.h> int error = fgetpos(fp, &pos); fpos_t pos; DESCRIPTION fgetpos returns the current seek position and is roughly equivalent to ftell. fgetpos is a new ANSI call to better support C compilers that use 16 bit integers. DICE uses 32 bit integers so fgetpos is not so useful. fgetpos takes a file pointer and the address of a fpos_t type (a long). It fills the fpos_t variable with the current file position and returns 0 if all went well, non-zero if an error occurred. || NOTE: Refer to the file_pointer manual page for general || information. INPUTS FILE *fp; file pointer fpos_t *pos; pointer to an fpos_t type that the position is loaded into. RESULTS int error; 0 if no error, non-zero on error SEE ALSO ftell, rewind, fseek, rewind EXAMPLE /* ** Return the length of the file specified on the ** command line. */ #include <stdio.h> main(int ac, char*av[]) { FILE *fp; fpos_t off; if (ac == 1) { puts("Expected a filename argument"); exit(1); } fp = fopen(av[1], "r"); if (fp == NULL) { printf("Unable to open %s\n", av[1]); exit(5); } fseek(fp, 0L, SEEK_END); if (fgetpos(fp, &off)) { puts("Error getting file position"); exit(20); } fclose(fp); printf("File %s is %d bytes long\n", av[1], off); return(0); } dice/fgets dice/fgets FUNCTION get a line from a file pointer (ANSI) SYNTAX #include <stdio.h> char *ptr = fgets(buf, maxlen, fp); char *buf; int maxlen; FILE *fp; DESCRIPTION fgets gets a line from the specified file pointer, returning the first argument (buf) or NULL if an error or EOF occurs. fgets stores the line in buf, up to maxlen characters. This maximum includes a terminating newline '\n' and NULL '\0'. If more than maxlen-1 characters are in the line fgets will terminate operation and put a NULL as the last character (so the buffer will still be a valid string). It is common to become confused by these functions: gets, puts These functions strip newline on input, add newline on output. gets works on stdin, puts on stdout. fgets, fputs These functions leave newlines alone on input, don't add to the output. Any file pointer, including stdin and stdout may be specified. || NOTE: Refer to the file_pointer manual page for general || information. INPUTS char *buf; buffer int maxlen; maximum buffer size FILE *fp; file pointer RESULTS char *ptr; buf if all is well, or NULL if error or EOF SEE ALSO gets, puts, fputs, fread, getc, fgetc EXAMPLE #include <stdio.h> main() { unsigned char buf[128]; short i; printf("Enter a line - "); fflush(stdout); if (fgets(buf, sizeof(buf), stdin) == NULL) exit(1); printf("In Hex: "); for (i = 0; buf[i]; ++i) printf(" %02x", buf[i]); puts(""); return(0); } dice/fhprintf dice/fhprintf FUNCTION formatted printing to a DOS file handle (AmigaDOS) SYNTAX #include <stdio.h> int n = fhprintf(fh, ctl, ...); BPTR fh; const char *ctl; DESCRIPTION fhprintf provides a method of using DICE's pfmt lib to do formatted printing to a file handle instead of a stdio file pointer. Output is unbuffered and thus not very efficient, but the call can be extremely useful when debugging libraries and such. If you have just a few things to print, and want to save the space the entire stdio package takes, you could use this function and _main. INPUTS BPTR fh; DOS file handle const char *ctl; format string, see printf() RESULTS int n; number of characters output SEE ALSO printf, sprintf, vsprintf, fprintf, vfprintf, _main EXAMPLE void _main(int ac, char**av) { fhprintf(Output(), "The answer is %d!\n", 42); } dice/file_descriptor dice/file_descriptor FUNCTION file descriptor DESCRIPTION A file descriptor is the lowest portable access to the file system a C program may make. File descriptors are used with open, read, write, close, etc. A file descriptor is unbuffered (that is, every operation goes to the kernel and does not get buffered locally). || NOTE: Remember that a file descriptor is different from a stdio || file pointer (see the file_pointer manual page) and an AmigaDOS || file handle. dice/fileno dice/fileno FUNCTION return file descriptor given a file pointer (UNIX) SYNTAX #include <stdio.h> int fd = fileno(fp); /* MACRO */ FILE *fp; DESCRIPTION The fileno macro returns the file descriptor (open, close, read, write) associated with the file pointer (fopen, fclose, fread, fwrite). This is still not the AmigaDOS file handle; to get that you must use the fdtofh call. ## WARNING: If you use the file descriptor of a file pointer the file ## pointer will get its seek position confused. Additionally, there ## might be unflushed data in the file pointer's buffers that has not ## been written out to the file descriptor yet. There also might be ## unread input on the file pointer's input buffers already read from ## the file descriptor. || NOTE: Refer to the file_pointer manual page for general || information. INPUTS FILE *fp; file pointer RESULTS int fd; associated file descriptor SEE ALSO fdopen, fopen, fclose, open, close dice/file_pointer dice/file_pointer FUNCTION STDIO file_pointer (ANSI) DESCRIPTION A file pointer is the basis for stdio, a standard file management package available across all versions of C. If you stick to the standard functions, your program should work on any machine that can compile C. The specific Amiga implementation builds file pointers (type "FILE *") on top of file descriptors (type "int"; see the file_descriptor manual page). File pointers have a layer of buffering (good if you use many small reads and writes), while file descriptors pass requests directly to AmigaDOS. Note that a stdio file pointer is not a file descriptor nor is a AmigaDOS file handle. You may call only stdio routines (fopen, fclose, fread, fwrite, etc.) with file pointers. Some C implementations flush stdout whenever stdin is read. DICE does not do this. dice/fopen dice/fopen FUNCTION open a file and create a file pointer (ANSI) SYNTAX #include <stdio.h> FILE *fp = fopen(filename, modes) char *filename; char *modes; DESCRIPTION fopen is the grand master of stdio: it opens and possibly creates a file and returns a new file pointer for use by the program. The first argument is the file to open, the second is a string containing one or mode characters defined as follows: Mode : Usage =====+=============================================================== r : open for reading, the file must already exist -----+--------------------------------------------------------------- w : open for writing, the file is created if it does not exist, : truncated if it does -----+--------------------------------------------------------------- a : open for append, writes always append to the file. -----+--------------------------------------------------------------- a : the file starts out positioned at the end instead of at the : beginning. This mode also creates the file but only if it : does not already exist. -----+--------------------------------------------------------------- r+ : also allows writing to the file in addition to reading -----+--------------------------------------------------------------- w+ : also allows reading from the file -----+--------------------------------------------------------------- b : open for binary read/write, else the file is assumed to : contain text (this is ignored by DICE since there is no : difference on the Amiga). -----+--------------------------------------------------------------- All combinations except "rw" are allowed. One uses "r+" or "w+" instead of "rw". By the above description "r+" is used to update an existing file while "w+" is used to create a new file and then allow reads as well as writes to it. "wa" is equivalent to creating a new file and then appending to it. "r+a" is equivalent to appending to an already existing file. Other examples of valid modes combinations: "r+b", "w+b", "rb", "wb", "ab", "w", "r", "r+", "a", etc... || NOTE: Refer to the file_pointer manual page for general || information. INPUTS char *filename; file name to open char *modes; open modes string RESULTS FILE *fp; new file pointer SEE ALSO fdopen, fclose, open, close EXAMPLE #include <stdio.h> main() { FILE *fp; char * filename = "t:XX"; char * why = "I don't do windows\n"; fp = fopen(filename, "wb"); if( fp ) { fwrite(why, 1, strlen(why), fp); fwrite(why, strlen(why), 1, fp); fclose( fp ); } else printf("Can't open file %s\n", filename); return(0); } dice/fputc,putc dice/fputc,putc FUNCTION fputc: write a single character (ANSI) putc: write a single character (ANSI) SYNTAX #include <stdio.h> int c = fputc(c, fp); int c = putc(c, fp); /* MACRO */ FILE *fp; DESCRIPTION fputc writes a single character to a file pointer. If all goes well the character is returned, else EOF is returned. fputc is a function call while putc is a macro || NOTE: Refer to the file_pointer manual page for general || information. INPUTS int c; character to write FILE *fp; file pointer RESULTS int c; character written (same as first argument) or EOF if error. SEE ALSO getc, putc, fputc, fread, fwrite, puts, fputs, gets, fgets EXAMPLE /* * copy stdin to stdout using fgetc/fputc. Normally one * uses fread/fwrite, but I'll save that for the fread * manual page. note that I output the initial message * to stderr so it does not get stuck into stdout in * case the user has redirected stdout. */ #include <stdio.h> main() { int c; fputs("Type a couple of lines, then ^\\ (EOF)\n", stderr); while ((c = fgetc(stdin)) != EOF) { fputc(c, stdout); } return(0); } dice/fputs,puts dice/fputs,puts FUNCTION fputs: write a string to a file pointer (ANSI) puts: then write a string to stdout, appending newline (ANSI) SYNTAX #include <stdio.h> int error = fputs(s, fp); int error = puts(s); const char *s; FILE *fp; DESCRIPTION fputs writes a string to a file pointer all the way up to, but not including, the NULL. puts does the same thing but to stdout, and puts additionally writes a newline out. || NOTE: Refer to the file_pointer manual page for general || information. It is common to get confused between fputs and puts. Remember that puts adds a newline to the output while fputs does not. gets strips the newline from an input line while fgets does not. INPUTS char *s; string to write FILE *fp; file pointer RESULTS int error; 0 or positive if all went ok, else negative. Note that unlike printf() routines the numberr of chars written out is NOT returned. SEE ALSO getc, putc, fputc, fread, fwrite, gets, fgets EXAMPLE #include <stdio.h> main() { /* note newline */ fputs("This is a test of fputs\n", stdout); puts("This is a test of puts"); /* note lack of */ puts("That's it!"); return(0); } dice/fseek dice/fseek FUNCTION seek within a file pointer (ANSI) SYNTAX #include <stdio.h> int error = fseek(fp, offset, how); FILE *fp; long offset; int how; DESCRIPTION fseek changes the current seek position within a file. Offset is interpreted according to the how argument: : : =========+===+===================================================== SEEK_SET : 0 : skip to position relative to beginning of file ---------+---+----------------------------------------------------- SEEK_CUR : 1 : skip to position relative to current position in : : file ---------+---+----------------------------------------------------- SEEK_END : 2 : skip to position relative to end of file. ---------+---+----------------------------------------------------- So, for example, one may seek to the beginning of a file by fseek(fp, 0L, SEEK_SET);, to the end of the file by fseek(fp, 0L, SEEK_END);. Calling getc at this time would return an immediate EOF. You can skip characters in a file with something like fseek(fp, 5L, SEEK_CUR); which skips 5 characters. Note that when seeking relative to the end of the file, negative offsets are used. For example, to seek to the very last character in the file you would use fseek(fp, -1L, SEEK_END); fseek returns 0 on success, a negative number on ERROR. A common mistake is to expect fseek to return the new position of the file but this is not what is returned. Use ftell or fgetpos to determine the current offset into a file. || NOTE: Refer to the file_pointer manual page for general || information fseek flushes any buffered write data before seeking. INPUTS FILE *fp; file pointer to seek long offset; relative offset, depending on how int how; 0, 1, or 2 (absolute, relative, end- relative) RESULTS int error; Error code from operation SEE ALSO ftell, fgetpos, fsetpos, rewind EXAMPLE see fopen for an example dice/fread dice/fread FUNCTION read data from a file pointer (ANSI) SYNTAX #include <stdio.h> size_t robjs = fread(buf, objsize, nobjs, fp); void *buf; size_t objsize; size_t nobjs; FILE *fp; DESCRIPTION fread reads an arbitrary number of objects from a file pointer into the specified buffer and returns the actual number of objects read. If the return value robjs is not equal to nobjs then fread was unable to read the requested number of objects due to either a read error or an EOF condition. If the file is already completely exhausted fread simply returns 0. Having two size arguments, an object size and a number of objects, simplifies the reading of structure arrays off disk. || NOTE: To use fread to read an arbitrary number of bytes one || normally uses the form: r = fread(buf, 1, n, fp); that is, n || objects of size 1. fread will attempt to read objsize * nobjs || bytes into the specified buffer. INPUTS void *buf; buffer to load data into size_t objsize; size of one object size_t nobjs; number of objects to read FILE *fp; file pointer to read objects from RESULTS size_t robjs; number of objects actually read or 0 if EOF or ERROR. SEE ALSO fwrite, fopen, fclose, fseek, ftell, rewind EXAMPLE #include stdlib.h #include stdio.h #define NOBJS 15 typedef struct { short a, b, c, d; } MyObj; main() { FILE *fp; MyObj O; if (fp = fopen("T:fwrite_tmp", "r")) { short n; for (n = 0; n < NOBJS; ++n) { O.a = n; O.b = n * 2; O.c = n * 3; O.d = n * 4; if (fread(&O, sizeof(MyObj), 1, fp) != 1) { printf("read error, eof is %d\n",feof(fp)); exit(1); } else { printf("read something, O.a is %d\n",O.a); } } fclose(fp); } return(0); } dice/free dice/free FUNCTION free memory allocated by calloc, malloc, or strdup (ANSI) SYNTAX #include <stdlib.h> void free(ptr); void *ptr; DESCRIPTION free frees memory allocated by calloc, malloc, or strdup. || NOTE: Under ANSI C, it is legal to free(NULL). This is, however, a || bad idea to depend on. Usually a free of the NULL pointer || indicates a bug in the code. INPUTS void *ptr; pointer to memory to free SEE ALSO malloc, calloc, strdup EXAMPLE see calloc example dice/freopen dice/freopen FUNCTION reopen a new file using an existing file pointer, the existing file is closed before it is reused (ANSI) SYNTAX #include <stdio.h> FILE *fp = freopen(filename, modes, ofp) char *filename; char *modes; FILE *ofp; DESCRIPTION freopen works exactly like fopen but takes an additional argument, a file pointer to reuse. This file pointer, ofp, must reference a valid open file. freopen will close out ofp then reuse the descriptor to open the new file, returning ofp (fp == ofp) on success, NULL on failure. If the freopen fails NULL is returned and the original file pointer is still closed, but not freed so you may call freopen again with the same ofp, even though it has already been closed. Refer to the fopen manual page for information on the modes string. freopen is often used to change a program's stdin, stdout, or stderr though to be frank, using a separate file pointer is normally much more modular. ## WARNING: ANSI does not specify that the ofp can be used in a ## second freopen if the first freopen using ofp fails (returns ## NULL). Many implementations free the file pointer. This just might ## be the proper way of doing things but we don't know. We suggest ## you do not use DICE's feature in that respect as we might have to ## change it back to free ofp if the new file is unopenable. || NOTE: Refer to the file_pointer manual page for general || information INPUTS char *filename; file name to open char*modes; open modes string FILE *ofp; open file pointer to reuse RESULTS FILE *fp; same as ofp if the new open worked, NULL otherwise SEE ALSO fdopen, fopen, fclose, open, close EXAMPLE /* * re-open stdin to an Amiga console device */ #include <stdio.h> #include <assert.h> main() { char buf[256]; assert(freopen("CON:0/0/320/100/freopen-in", "r", stdin)); assert(freopen("CON:320/0/320/100/freopen-out", "w", stdout)); /* * set to line buffered */ setvbuf(stdin, NULL, _IOLBF, 0); setvbuf(stdout, NULL, _IOLBF, 0); puts("Type a (short) line in the second window"); gets(buf); fclose(stdin); fclose(stdout); fprintf(stderr, "Your line was: %s\n", buf); return(0); } dice/fsetpos dice/fsetpos FUNCTION set position within file pointer (nearly equivalent to fseek absolute) (ANSI) SYNTAX #include <stdio.h> int error = fsetpos(fp, &pos); FILE *fp; fpos_t pos; DESCRIPTION fsetpos is a nearly useless call that is essentially the same as fseek(fp, (long)pos, 0); fsetpos seeks within a file pointer to the absolute position specified by an fpos_t type. The address of an fpos_t object is passed to fsetpos. Normally one saves the current seek position into an fpos_t type using the fgetpos function, then seeks back using the fsetpos function. In this way the programmer need not make any direct reference to the contents of the fpos_t type. INPUTS FILE *fp; file pointer to seek fpos_t *pos; pointer to fpos_t type previously initialized by a fgetpos() call. RESULTS int error; 0 if no error, < 0 if error SEE ALSO ftell, fsetpos, fseek, rewind EXAMPLE /* * get a line, save current position, get rest of * file, go back to saved position, retrieve line * again and print again. */ #include <stdio.h> main(int ac, char*av[]) { FILE *fp; fpos_t save_pos; int count; char buf[256]; if (ac == 1) { puts("Expected textfile argument"); exit(1); } fp = fopen(av[1], "r"); if (fp == NULL) { printf("Unable to open %s\n", av[1]); exit(1); } for (count = 0; fgets(buf, sizeof(buf), fp); ++count) { if (count == 0) /* just before second line */ fgetpos(fp, &save_pos); fprintf(stdout, "%-3d: %s", count + 1, buf); } if (count < 2) { puts("not enough lines in file for example!"); exit(1); } puts("--end of file, now seeking back to line 2--"); fsetpos(fp, &save_pos); if (fgets(buf, sizeof(buf), fp) == NULL) { puts("error!"); exit(1); } fprintf(stdout, "%-3d: %s", 2, buf); fclose(fp); return(0); } dice/fstat dice/fstat FUNCTION stat a file descriptor (UNIX) SYNTAX #include <sys/stat.h> int error = fstat(fd, &stat_buf); struct stat stat_buf; DESCRIPTION fstat is a UNIX-compatible call that returns information pertaining to the file represented by an open file descriptor. See stat for information on the struct stat fields. || NOTE: fstat works just like stat except you provide a UNIX file || descriptor (not an AmigaDOS File Handle). || Under 2.0, ExamineFH is used. Under 1.3, the original path used || to open the file will be stat'd, which ends up scanning the || directory if the file was open for exclusive access. INPUTS int fd; file descriptor to stat struct stat *sbuf; address of stat structure that will be filled in RESULTS int error; 0 on success, < 0 on error SEE ALSO chdir EXAMPLE #include <stdio.h> #include <fcntl.h> #include <sys/stat.h> main(int ac, char**av) { int r, fd; struct stat stat_buf; if (ac == 1) { puts("Expected a file name"); exit(1); } fd = open(av[1], O_RDONLY ); if( fd ) { r = fstat(fd, &stat_buf); if (r < 0) printf("Can't stat fd=%d\n", fd); else { printf("File is %d bytes\n", stat_buf.st_size); printf("modified %s", ctime(&stat_buf.st_ctime)); } close(fd); } return(0); } dice/ftell dice/ftell FUNCTION return current position within file pointer (ANSI) SYNTAX #include <stdio.h> long pos = ftell(fp); FILE *fp; DESCRIPTION ftell returns the current absolute seek offset within a file pointer. INPUTS FILE *fp; file pointer retrieve seek position from RESULTS long pos; current absolute seek position in file SEE ALSO ftell, fgetpos, fsetpos, fseek, rewind EXAMPLE /* * get a line, save current position, get rest of file, * go backto saved position, retrieve line again and * print again. * like fsetpos() example but uses ftell()/fseek() * instead */ #include <stdio.h> main(int ac, char**av) { FILE *fp; long save_pos; int count; char buf[256]; if (ac == 1) { puts("Expected textfile argument"); exit(1); } fp = fopen(av[1], "r"); if (fp == NULL) { printf("Unable to open %s\n", av[1]); exit(1); } for (count = 0; fgets(buf, sizeof(buf), fp); ++count) { if (count == 0) /* just before second line */ save_pos = ftell(fp); fprintf(stdout, "%-3d: %s", count + 1, buf); } if (count < 2) { puts("not enough lines in file for example!"); exit(1); } puts("--end of file, now seeking back to line 2--"); fseek(fp, save_pos, SEEK_SET); if (fgets(buf, sizeof(buf), fp) == NULL) { puts("error!"); exit(1); } fprintf(stdout, "%-3d: %s", 2, buf); fclose(fp); return(0); } dice/fwrite dice/fwrite FUNCTION write data to a file pointer (ANSI) SYNTAX #include <stdio.h> size_t robjs = fwrite(buf, objsize, nobjs, fp); const void *buf; size_t objsize; size_t nobjs; FILE *fp; DESCRIPTION fwrite writes the specified number of objects to a file pointer from the specified buffer and returns the actual number of objects written or 0 or -1 depending on the error. If the return value robjs is not equal to nobjs then a write error occurred. Having two size arguments, an object size and number of objects, simplifies the reading of structure arrays off disk. || NOTE: To use fwrite to read an arbitrary number of bytes one || normally uses the form "r = fwrite(buf, 1, n, fp);", that is, n || objects of size 1. INPUTS void *buf; buffer to copy data from size_t objsize; size of one object size_t nobjs; number of objects to write FILE *fp; file pointer to read objects from RESULTS size_t robjs; number of objects actually written (0 or EOF on error) SEE ALSO fread, fopen, fclose, fseek, ftell, rewind dice/getchar dice/getchar FUNCTION get character from stdin (ANSI) SYNTAX #include <stdio.h> int c = getchar(); /* MACRO */ DESCRIPTION getchar returns the next available character on stdin or EOF if no more characters are available. getchar is equivalent to getc(stdin). || NOTE: Refer to the file_pointer manual page for general || information. INPUTS none RESULTS int c; character 0 to 255, or EOF (-1) returned from stdin SEE ALSO putc, putchar, fputc, fread, fwrite, getc EXAMPLE /* * copy stdin to stdout using getchar/putchar. Normally * one uses fread/fwrite, but I'll save that for the * fread manual page. * Note that I output the initial message to stderr * so it does not get stuck into stdout in case the * user has redirected stdout. * * See getc manual page for equivalent example using * getc/putc */ #include <stdio.h> main() { int c; fputs("Type a couple of lines, then ^\\ (EOF)\n", stderr); while ((c = getchar()) != EOF) { putchar(c); } return(0); } dice/getcwd dice/getcwd FUNCTION get current working directory (UNIX) SYNTAX #include <stdio.h> char *path = getcwd(buf, max); non-standard call DESCRIPTION getcwd gets the current working directory and puts it into the specified buffer buf. If buf is NULL it will be malloc'd automatically. The parameter buf is returned (or the malloc'd buffer if you passed NULL for buf). The parameter max specifies the maximum length of the path including the terminating NULL character. NULL is returned if any error occurs (such as malloc failing) INPUTS char *buf; buffer to place current directory path into or NULL if you want getcwd to allocate one int max; maximum size of buffer RESULTS char *path; returns allocated buffer if you passed NULL for buf, else returns the first argument. Returns NULL on error. SEE ALSO chdir EXAMPLE #include <stdio.h> char buf[512]; main(int ac, char**av) { getcwd(buf, sizeof(buf)); printf("Current directory is: %s\n", buf); return(0); } dice/GetDiceRexxPortSlot dice/GetDiceRexxPortSlot FUNCTION Determine an Application ARexx slot (DICE) SYNTAX #include <lib/rexx.h> slot = GetDiceRexxPortSlot(port, &nameptr); int slot; MsgPort *port; char *nameptr; DESCRIPTION GetDiceRexxPortSlot returns the ln_Name field of the specified port (i.e. the fully qualified port name) and extracts and returns the slot number. -1 is returned if the port name does not terminate with ".xx" where xx is a number. If a char ** pointer is passed as nameptr it will be initialized to point to the ln_Name field of the port. This call is normally used with port = NULL to obtain information about DICE's internally setup Rexx port. INPUTS struct MsgPort *port; message port structure to extract ln_Name and slot field from. You can pass NULL to extract the full name and slot number selected by DICE when automatic startup is used (i.e. your declaration of RexxHostName is assigned a non-NULL pointer). char **nameptr; The port name or NULL. If not NULL the pointer will be assigned the ln_Name field of the port. Normally used when port is passed as NULL to obtain the fully qualified rexx port name DICE has constructed for you in an automatic startup. RESULTS int slot; the slot number extracted from the port name or -1 if the port name is not in the proper format. SEE ALSO CreateGlobalDiceRexxPort, CreateDiceRexxPort, DeleteDiceRexxPort EXAMPLE See DICE ARexx Support in chapter dice/getenv dice/getenv FUNCTION get environment variable (ANSI) SYNTAX #include <stdlib.h> char *var = getenv(const char *name); DESCRIPTION getenv searches for and returns the ENV: environment variable requested. getenv will cache variables so that requesting the same variable repeatedly does not allocate a new memory buffer. getenv allocates a buffer for each variable returned, so you do not have to copy the return value from getenv. This memory is free'd on program exit. Do not attempt to free a getenv'd variable!! INPUTS char *name; Name of environment variable, on the Amiga this is not case sensitive. On UNIX systems it is. RESULTS char *var; Contents of environment variable or NULL if the variable could not be found. EXAMPLE #include <stdio.h> #include <stdlib.h> main(int ac, char**av) { char *dccopts = getenv("DCCOPTS"); if (dccopts) printf("DCCOPTS = %s\n", dccopts); else printf("You do not have a DCCOPTS environment\ variable!\n"); return(0); } dice/getfnl dice/getfnl FUNCTION get file name list: scan directory, return list of files that match the optional wildcard (DICE) SYNTAX #include <stdlib.h> int n = getfnl(pat, buf, bufsize, attr); const char *pat; char *buf; int bufsize; int attr; DESCRIPTION getfnl scans the specified anchored AmigaDOS pattern and fills the specified buffer (up to bufsize bytes) with file names separated by a NULL character (\0), ending the list with a double NULL (\0\0). getfnl returns the number of files/dirs in the buffer or -1 if there is not enough room The pattern pat is an AmigaDOS pattern such as "df0:#?.c". The parameter buf is a buffer of bufsize bytes. The parameter attr determines what kinds of files are valid: 0 for normal files only, 1 for files and directories || NOTE: getfnl exists for compatibility only; expand_args is a much || better function function to use if you want a list of files & || dirs. INPUTS const char *pat; pattern to scan for (anchored) char *buf; buffer to put results in int bufsize; size of buffer int attr; attribes (0 or 1) RESULTS int n; number of file names in buffer or -1 on error SEE ALSO strbpl, expand_args EXAMPLE #include <stdio.h> char Buf[4096]; main(int ac, char**av) { int n; if (ac != 2) { puts("Expected an anchored wildcard such as '#?'"); exit(1); } n = getfnl(av[1], Buf, sizeof(Buf), 1); { char *ptr = Buf; while (*ptr) { /* look for \0\0 */ puts(ptr); ptr += strlen(ptr) + 1; /* skip first \0 */ } } return(0); } dice/GetHead,GetTail,GetSucc,GetPred dice/GetHead,GetTail,GetSucc,GetPred FUNCTION Manipulate EXEC style lists (DICE) SYNTAX #include <lists.h> struct Node *node = GetHead(list); struct Node *node = GetTail(list); struct Node *node = GetSucc(oldNode); struct Node *node = GetPred(oldNode); const struct Node *oldNode; const struct List *list; DESCRIPTION These functions allow scanning of EXEC style lists (which are also useful for many programs having nothing to do with EXEC). GetHead returns the first node in a list or NULL if the list is empty; GetTail returns the last node in a list or NULL if the list is empty; GetSucc returns the next node in a list (given some intermediate node) or NULL when we reach the end of the list GetPred returns the previous node in a list before some intermediate node or NULL when we reach the beginning of the list || NOTE: These are DICE functions and do not exist outside of DICE, || though they could be easily written. INPUTS struct List *list; list to get head or tail node from struct Node *oldNode; node from which to get relative successor or predecessor from RESULTS struct Node *node; returned node or NULL EXAMPLE /* * A simple symbol create/delete/list program. * (Note: for a real symbol table you'd want * to use hash tables) */ #include <lists.h> /* non-standard header file */ #include <stdio.h> #include <stdlib.h> #include <string.h> typedef struct List List; typedef struct Node Node; List SymList; void AddSymbol(char *); void DelSymbol(char *); Node *FindSymbol(char *); main() { char buf[256]; char symBuf[256]; short notDone = 1; NewList(&SymList); puts("(return for help)"); while (notDone) { printf("Enter Command: "); fflush(stdout); if ( fgets(buf, sizeof(buf), stdin) == NULL) break; switch(buf[0]) { case 'a': if (sscanf(buf + 1,"%s",symBuf)== 1) AddSymbol(symBuf); break; case 'd': if (sscanf(buf + 1,"%s",symBuf)== 1) DelSymbol(symBuf); break; case 'l': { Node *node; for (node = GetHead(&SymList); node; node = GetSucc(node)) puts(node->ln_Name); } break; case 'q': notDone = 0; break; default: puts("<return> -help "); puts("a name-add symbol"); puts("d name-delete symbol"); puts("l -list symbols"); puts("q -quit"); break; } } puts("bye!"); return(0); } void AddSymbol(name) char *name; { Node *node; if (FindSymbol(name)) { puts("already exists!"); exit(1); } if (node = malloc(sizeof(Node))) { AddTail(&SymList, node); node->ln_Name = strdup(name); /* bad code, not checking */ /* for error result! */ } } void DelSymbol(name) char *name; { Node *node; if (node = FindSymbol(name)) { Remove(node); /* take out of list */ free(node->ln_Name); /* free name */ free(node); /* free node last */ puts("ok"); } else { puts("Couldn't find it!"); } } Node * FindSymbol(name) char *name; { Node *node; for (node = GetHead(&SymList); node; node = GetSucc(node)) { if (strcmp(node->ln_Name, name) == 0) return(node); } return(NULL); } dice/gets dice/gets FUNCTION get a line from stdin (ANSI) SYNTAX #include <stdio.h> char *ptr = gets(buf); char *buf; DESCRIPTION gets takes a line from stdin and places it into your buffer. A null (\0) is placed in the buffer instead of the newline (\n). While the function can be convenient, if your buffer is not large enough, you loose. See fgets for a more reasonable function. gets, puts These functions strip newline on input, add newline on output. gets works on stdin, puts on stdout. fgets, fputs These functions leave newlines alone on input, don't add to the output. Any file pointer, including stdin and stdout may be specified. || NOTE: Refer to the file_pointer manual page for general || information. INPUTS char *buf; buffer, must be able to maximum possible line RESULTS char *ptr; buf if all is well, or NULL if error or EOF SEE ALSO puts, fputs, fgets, fread, getc, fgetc EXAMPLE #include <stdio.h> main() { char buf[128]; printf("Enter a line - "); fflush(stdout); if (gets(buf) == NULL) // Enter a long line to crash exit(1); printf("Your line was: %s\n", buf); return(0); } dice/isalnum,isalpha,iscntrl,isdigit,isgraph,islower,isprint,ispunct,isspace,isupper,isxdigit FUNCTION Test a character for assorted attributes (ANSI) SYNTAX #include <ctype.h> int r = isxxxxx(c); int c; || NOTE: These are MACROS if you #include <ctype.h>, function calls || if you do not. DESCRIPTION These function return non-zero (true) if the test is true, and zero (false) if not. || NOTE: When a non-zero value is returned, this value might be || anything other than zero. It is not necessarily a 1. It is || guaranteed to fit in a short, however, and still remain || non-zero. || || Characters in the -1 to 255 range are valid inputs. Characters || less than -1 or larger than 255 are illegal and the results will || be random. If you are passing a CHAR, you must cast it to an || UNSIGNED CHAR first. EOF is a valid input, and always returns || false isalpha Returns non-zero if the character is a letter in the alphabet (a-z, A-Z). isalnum Returns non-zero if the character is alphanumeric (a-z, A-Z, 0-9). iscntrl Returns non-zero if the character is a control character (decimal 0 to 31). isdigit Returns non-zero if the character is a digit ('0' through '9'). isgraph Returns non-zero if the character is printable and not a space. isgraph is the same as isprint, but with the space character excluded from the printable set. islower Returns non-zero if the character is a lower case letter 'a' - 'z'. isprint Returns non-zero if the character is printable. isprint is the same as isgraph, but with the space character included in the printable set. ispunct Returns non-zero if the character is any sort of punctuation, including punctuation in the extended ASCII range. Basically, if it is not a control character, alpha or a digit, it is punctuation. isspace Returns non-zero if the character is any sort of white space. Included are space, shifted space, line feed (lf), form feed (ff), carriage return (cr), tab, and vertical tab. isupper Returns non-zero if the character is an upper case letter 'A' -'Z'. isxdigit Returns non-zero if the character is a valid hexadecimal digit '0' - '9', 'a' - 'f', or 'A' - 'F'. These macros use a lookup table. One table handles the eight most common functions. A second table handles ispunct, isxdigit and isprint. It saves space if you reference only one table. There is space in the second table if you wish to add your own tests (you'll have to recompile the library source code). INPUTS int c; character that we are checking RESULTS int r; 0 if the check failed, non-zero if the check is true SEE ALSO tolower, toupper #include <stdio.h> #include <ctype.h> main() { int c; for( c=0; c<256; c++) { if( (c & 31) == 0 ) /* 32 per line */ printf("\n%02x: ", c); if( isprint( c ) ) printf("%c", c ); /* character */ else printf("%c", 127 ); /* placeholder */ } printf("\n"); for( c=0; c<256; c++) { if( (c & 31) == 0 ) /* 32 per line */ printf("\n%02x: ", c); if( ispunct( c ) ) printf("x"); /* true */ else printf("-"); /* false */ } printf("\n"); return( 0 ); } dice/isatty dice/isatty FUNCTION Test if a a file descriptor is a TTY (UNIX) SYNTAX #include <ctype.h> int r = isatty(fd); int fd; DESCRIPTION isatty returns TRUE (1) if the file descriptor is associated with a console, FALSE (0) if not, or -1 if an error condition occurs (such as illegal file descriptor). || NOTE: The standard input (0), standard output (1), and standard || error (2) can all return different values for isatty depending on || how the program is redirected. A program whose standard in and || standard out is redirected may still have a standard error that is || connected to the console. Refer to the file_descriptor manual page || for general information. Unlike file pointers and file handles, || the file descriptor is checked for validity and will simply return || an error if illegal. INPUTS int fd; file descriptor RESULTS int r; result, 1 if a tty, 0 if not, or -1 if error SEE ALSO close, creat, fcntl, fdtofh, getfh, ioctl, lseek, mkdir, open, read, rmdir, unlink, write dice/ioctl dice/ioctl FUNCTION IO control on file descriptor (UNIX) SYNTAX #include <fcntl.h> int r = ioctl(fd, req, parg1, parg2); int fd; int req; int *parg1; int *parg2; DESCRIPTION ioctl executes an IO control on the file descriptor. Currently no IO controls are implemented. INPUTS int fd; file descriptor int req; request from <ioctl.h> int *parg1; address of argument #1 int *parg2; address of argument #2 RESULTS int r; result, error if < 0. SEE ALSO close, creat, fcntl, fdtofh, getfh, isatty, lseek, mkdir, open, read, rmdir, unlink, write dice/localtime dice/localtime FUNCTION convert time into broken down time (ANSI) SYNTAX #include <time.h> struct tm *tp = localtime(&t); time_t t; DESCRIPTION localtime takes the address of a time_t variable and breaks up the time into component parts, storing them in a static tm structure. The address of this structure is returned. Since the broken up time is stored into a static structure, the structure will get overwritten on the next call to localtime. The fields of the tm structure are: struct tm { int tm_sec; /* 0-59 */ int tm_min; /* 0-59 */ int tm_hour; /* 0-23 */ int tm_mday; /* 1-31 */ int tm_mon; /* 0-11 */ int tm_year; /* n+1900 */ int tm_wday; /* (sun)0-6*/ int tm_yday; /* 0-366 */ int tm_isdst; /* is daylight savings? */ /* (DICE does not implement the is daylight flag) */ }; INPUTS time_t *t; pointer to a time_t RESULTS struct tm *tp; pointer to a struct tm structure filled out according to the passed time. SEE ALSO time, asctime, strftime, ctime, clock EXAMPLE /* * Note that it is much easier to format time/date * strings with strftime(). */ #include <stdio.h> #include <time.h> main() { time_t t = time(NULL); struct tm *tp = localtime(&t); printf("The time is %02d:%02d:%02d\n", tp->tm_hour, tp->tm_min, tp->tm_sec); return(0); } dice/LockAddr,LockAddrB,TryLockAddr,TryLockAddrB,UnlockAddr,UnlockAddrB FUNCTION LockAddr: Gain Exclusive, Fast semaphore (bit 0) LockAddrB: Gain Exclusive, Fast semaphore (bit n 0-7) TryLockAddr: Non- Blocking version of LockAddr TryLockAddrB: Non-Blocking version of LockAddrB UnlockAddr: Release exclusive semaphore, bit 0 UnlockAddrB: Release exclusive semaphore, bit n 0-7 (DICE) SYNTAX void LockAddr(lck); void LockAddrB(bitno, lck); int r = TryLockAddr(lck); int r = TryLockAddrB(bitno, lck); void UnlockAddr(lck); void UnlockAddrB(bitno, lck); long lck[2]; DESCRIPTION These are custom DICE functions used for inter-task locking semaphores in programs that need such functions. These routines are somewhat faster than standard Amiga semaphore routines and take less memory, though at the cost of DICE specific. To use an inter-task lock one first initializes an lck array to 0's. The entry long lck[2]; is an array of two longwords that the lock routines will use to do their stuff. This array should be zero'd only once at program initialization time (the master task before any other tasks are created that use it). Each lck array may hold up to 8 locks, hence the LockAddrB calls. The non-B calls use lock #0 for simplicity. For simplicity we will only discuss non-B calls. To gain a lock you may call LockAddr with the address of the lck array (which, being an array, does not need the & in the call). This routine will not return until the lock can be obtained. You may also use TryLockAddr to attempt to gain a lock. The return value is: -1 if the command is unable to obtain the lock (that is, it is in use), 1 if the lock has been obtained. To release an obtained lock you call UnlockAddr(lck). ## WARNING: DO NOT RELEASE A LOCK YOU DO NOT HAVE! INPUTS long *lck; a pointer to two longwords, initially zero'd -int bitno; lock # ... up to 8 independent locks exist for each lck structure RESULTS int r; (TryLock only), -1 on failure, 1 on success. EXAMPLE /* * This program obtains a lock based at a public * message port and holds it for ten seconds before * releasing it. The public message port is left * in memory (but only exists once no matter how * many programs you run). * * To test locking, open up two or more CLI's and run * the program simultaneously (or as close as your * fingers can make it) two or more times. Only one * program will 'have' the lock at a time. * * we use AllocMem() so the port survives the program */ #include <exec/types.h> #include <exec/ports.h> #include <exec/memory.h> #include <stdio.h> #include <stdlib.h> #include <assert.h> typedef struct { struct MsgPort Port; long Lock[2]; } MyPort; extern void *FindPort(); extern void *CreatePort(); extern void *AllocMem(); MyPort *Port; short HaveLock; int brk() { if (HaveLock) UnlockAddr(Port->Lock); return(1); /* abort */ } main() { char *portName = "Lock-Test"; onbreak(brk); Forbid(); if ((Port = FindPort(portName)) == NULL) { MyPort *port; port = AllocMem(sizeof(MyPort) + strlen(portName) + 1, MEMF_PUBLIC | MEMF_CLEAR); assert(port); port->Port.mp_Node.ln_Name = (char *)(port + 1); port->Port.mp_Node.ln_Type = NT_MSGPORT; strcpy(port->Port.mp_Node.ln_Name, portName); AddPort(port); Port = port; } Permit(); puts("getting lock"); LockAddr(Port->Lock); HaveLock = 1; puts("Got the lock!, sleeping for 10 seconds"); sleep(10); UnlockAddr(Port->Lock); HaveLock = 0; puts("released lock"); return(0); } dice/log,flog dice/log,flog FUNCTION log: return the log of a double, base e (ANSI) flog: return the log a float, base e (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = log(b); double b; float c = flog(d); float d; DESCRIPTION The former command returns the log of the double quantity, base e; the latter returns the log of the float quantity, base e. INPUTS double b; double floating point value float d; float floating point value RESULTS double a; result double floating point value float c; result float floating point value SEE ALSO acos, asin, atan, cos, exp, fabs, log10, pow, sin, sqrt, tan facos, fasin dice/log10,flog10 dice/log10,flog10 FUNCTION log10: return the logarithm of a double, base 10 (ANSI) flog10: return the logarithm of a float, base 10 (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = log10(b); double b; float c = flog10(d); float d; DESCRIPTION log10 returns the log of a double quantity, base 10; flog10 returns the log of the floating point quantity, base 10. INPUTS double b; double floating point value float d; float floating point value RESULTS double a; result double floating point value float c; result float floating point value SEE ALSO acos, asin, atan, cos, exp, fabs, log, pow, sin, sqrt, tan facos, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = log10(0.25); printf("log10 0.25 = %lf\n", a); /* -0.6021 */ } { /* less accuracy */ float a = flog10(0.25); printf("log10 0.25 = %lf\n", (double)a); } return(0); } dice/lseek dice/lseek FUNCTION seek within a file descriptor (UNIX) SYNTAX #include <fcntl.h> long newpos = lseek(fd, offset, how) int fd; long offset; int how; DESCRIPTION lseek changes where the file descriptor points to within the open file. You may specify an offset relative to the beginning of the file, the current position in the file, or the end of the file: Val : Purpose ====+========================================================= 0 : absolute offset (relative to the beginning of the file) ----+--------------------------------------------------------- 1 : offset relative to the current position in the file ----+--------------------------------------------------------- 2 : offset relative to the end of the file ----+--------------------------------------------------------- Negative offsets may be specified when relative modes are used. The function lseek returns the new position in the file relative to the beginning of the file (i.e. an absolute offset). || NOTE: offsets are relative. So, for example, if you want to seek || to the fourth character from the end of the file you would || lseek(fd, -4L, 2);. Refer to the file_descriptor manual page for || general information. Unlike file pointers and file handles, the || file descriptor is checked for validity and will simply return an || error if illegal. INPUTS int fd; file descriptor long offset; offset relative to how int how; 0 = rel beginning, 1 = rel middle, 2 = rel end RESULTS int newpos; new position in file (absolute) or < 0 if error SEE ALSO close, creat, fcntl, fdtofh, getfh, ioctl, isatty, mkdir, open, read, rmdir, unlink, write EXAMPLE See open for an example. dice/main dice/main FUNCTION main program entry (ANSI) SYNTAX #include <anything.h> int main(int argc, char **argv) { /* your pride and joy goes here */ } DESCRIPTION The main routine is the entry point called after normal initialization of c.lib and the program environment is done by the startup module (c.o) and _main routine (in c.lib). Under ANSI C main is expected to return an integer exit code. You can no longer simply fall through without returning any value. Returning an exit code from your main routine is exactly the same as exiting with it. || NOTE: Any program run from the WORKBENCH uses a different access || point. Specifically, a program run from the WORKBENCH will run || wbmain instead of main. Please refer to the manual page for || wbmain for WORKBENCH operation. If you do not supply a wbmain a dummy wbmain will be supplied by the library which simply exits out of the program. INPUTS int argc; number of arguments char *argv; array pointer to arguments SEE ALSO wbmain, _main, exit, _exit EXAMPLE /* Print back out all given arguments */ #include <stdio.h> int main(int ac, char**av) { int i; for (i = 0; i < ac; ++i) { printf("Arg #%d = %s\n", i, av[i]); } return(0); } dice/_main dice/_main FUNCTION main program entry, bypass standard c.lib initialization (DICE) SYNTAX #include <the_world.h> void _main(int arglen, char *argptr) { /* your very special code goes here */ } DESCRIPTION The _main entry point is called by the startup module (c.o). Normally _main is part of c.lib and does stdio and other initialization before calling the user main routine. _main is responsible for opening the stderr channel as well. However, if you specify your own _main you will override the c.lib version. Normally you either fall through or _exit from _main. A programmable can use the _main entry point when the executable uses nothing but system library routines. That is, you make no calls to stdio functions such as puts, printf, etc., to low level IO routines such as open, close, read, etc., or malloc or any routine that uses malloc. Self contained routines such as strcpy may still be called, and, of course, you may open any libraries you wish and make library calls. Since the auto-library opening and closing is done by the startup module (c.o), "dos.library" will still be opened for you automatically if you make any DOS calls. Using the _main entry point usually results in a substantially smaller executable because stdio and other library routines referenced by the c.lib. _main and exit are never referenced and thus never become part of the executable. It is NOT SUGGESTED that beginning C programmers use the _main entry point. || NOTE: _main is called by the startup module whether the program || was run from the CLI or the WORKBENCH. You must detect which || yourself and also deal with the WORKBENCH message yourself. int argc; number of arguments char *argv; array pointer to arguments SEE ALSO _exit, main, exit EXAMPLE /* ** This program comes in at under 600 bytes. */ _main() { Write(Output(), "UG!\n", 4); _exit(0); } dice/malloc dice/malloc FUNCTION allocate memory, the memory is NOT automatically cleared (ANSI) SYNTAX #include <stdlib.h> void *ptr = malloc(bytes); size_t bytes; DESCRIPTION malloc allocates the specified number of bytes of memory. The returned pointer is longword aligned; malloc returns NULL if the memory could not be allocated. || NOTE: Unlike calloc, malloc does not zero the memory before it || returns. INPUTS size_t bytes; number of bytes to allocate RESULTS void *ptr; pointer to base of allocated memory. The memory is not zero'd. SEE ALSO calloc, strdup dice/memcmp dice/memcmp FUNCTION compare two memory buffers (ANSI) SYNTAX #include <string.h> int r = memcmp(s1, s2, bytes) void *s1; void *s2; size_t bytes; DESCRIPTION memcmp compares two memory buffers. A byte by byte unsigned comparison is done. When a comparison fails and the byte in s1 is less than the byte in s2 then -1 is returned. If the byte in s1 is greater than the byte in s2 then 1 is returned. If the count is exhausted and all comparisons succeed then 0 is returned indicating the two buffers are the same. INPUTS void *s1; pointer to first buffer void *s2; pointer to second buffer size_t bytes; size of each buffer RESULTS int r; -1 if buf s1 < buf s2, 0 if buf s1 == buf s2, 1 if buf s1 > buf s2. SEE ALSO memset, setmem, bzero, clrmem, bcopy, bcmp, movmem, memcpy, memmove EXAMPLE #include <stdlib.h> #include <assert.h> main() { unsigned char buf1[5] = {9, 10, 1, 12}; /* 1,729 */ unsigned char buf2[5] = {9, 10, 1, 12}; /* 1,729 */ int r; r = memcmp(buf1, buf2, 4); assert(r == 0); buf1[2] = 0; r = memcmp(buf1, buf2, 4); assert(r < 0); buf1[2] = 42; r = memcmp(buf1, buf2, 4); assert(r > 0); return(0); } dice/memcpy,memmove,movmem,bcopy dice/memcpy,memmove,movmem,bcopy FUNCTION memcopy: copy memory, ANSI, overlapped memory buffers illegal memmov: copy memory, ANSI, works with overlapped memory buffers movmem: copy memory, UNIX, works with overlapped memory buffers bcopy: copy memory, UNIX, works with overlapped memory buffers SYNTAX #include <string.h> void *ptr = memcpy(d, s, bytes); void *ptr = memmove(d, s, bytes); void *ptr = movmem(s, d, bytes); void *ptr = bcopy(s, d, bytes); void *d; void *s; size_t bytes; DESCRIPTION These functions copy memory from one region to another. Unlike string routines these functions do not stop the copy when a NULL is encountered. ## WARNING: Be careful about argument ordering. Some calls take the ## source buffer first and other calls take the destination buffer ## first. The ANSI committee opted for a destination, source ordering rather than the more logical source, destination ordering. Thus, many programmers will use the non-standard movmem call instead of the ANSI memmove call. The ANSI function 'memcpy' as defined by the ANSI standard cannot handle overlapped memory areas. The Amiga implementation can but you should remember this if you intend to port your code. || NOTE: DICE's memory move optimizes the copy using movem when || possible, yielding very fast memory copies for large buffers. The || UNIX bcopy call exists for compatibility purposes and should not || be used with new programs. INPUTS void *s; source buffer void *d; destination buffer RESULTS void *ptr; pointer to the destination buffer(d) SEE ALSO memset, setmem, bzero, clrmem, cmpmem, memcmp EXAMPLE /* * This example copies the entire buffer, not just * the part containing the string. Normally one just * uses string routines. */ #include <string.h> #include <assert.h> main() { char s[16]; char d[16]; void *p; strcpy(s, "This is a test"); p = movmem(s, d, sizeof(s)); assert(p == d); puts(d); strcpy(s, "Googolplex"); p = bcopy(s, d, sizeof(s)); assert(p == d); puts(d); strcpy(s, "EchoBeko"); p = memcpy(d, s, sizeof(s)); assert(p == d); puts(d); strcpy(s, "GakFuBar"); p = memmove(d, s, sizeof(s)); assert(p == d); puts(d); return(0); } dice/memset,setmem,clrmem,bzero dice/memset,setmem,clrmem,bzero FUNCTION memset: ANSI, set memory buffer to a byte value setmem: UNIX, set memory buffer to a byte value clrmem: DICE, zero out a memory buffer bzero: UNIX, zero out a memory buffer SYNTAX #include <string.h> void *ptr = memset(buf, c, n); void *ptr = setmem(buf, n, c); void *ptr = clrmem(buf, n); void *ptr = bzero(buf, n); void *buf; int c; size_t n; DESCRIPTION These functions fill a memory buffer with the specified character c. C is converted to an unsigned character by the fill routine before beginning the fill. N bytes are filled. ## WARNING: Again, watch out for argument ordering, especially for ## the ANSI memset call. The ANSI committee chose bizarre call ordering so there is another defacto standard call called setmem. The function bzero exists for UNIX compatibility, and clrmem is yet another call (this time introduced by DICE--sorry!). memset and setmem are the most portable calls. INPUTS void *buf; pointer to buffer to fill int c; character to copy into buffer (setmem, memset) size_t n; # of bytes to fill RESULTS void *ptr; pointer to buffer (== buf). SEE ALSO malloc, calloc, strdup, movmem, cmpmem EXAMPLE #include <string.h> #include <assert.h> #include <stdlib.h> main() { char buf[32]; char *b; b = setmem(buf, 32, 0); assert(b == buf); b = setmem(buf, 4, 'a'); b = memset(buf + 4, 'b' , 4); puts(buf); /* aaaabbbb */ return(0); } dice/mkdir dice/mkdir FUNCTION create a directory (UNIX) SYNTAX #include <stdio.h> int error = mkdir(dirname) char *dirname; DESCRIPTION mkdir creates a new directory. It returns 0 if successful, -1 if not (with errno set to an error code). INPUTS char *dirname; filename of directory to create RESULTS int r; 0 if no error, < 0 if error SEE ALSO close, creat, fcntl, fdtofh, getfh, ioctl, isatty, lseek, mkdir, open, read, rmdir, unlink, write EXAMPLE main() { int r; r = mkdir("T:tmpdir"); if (r == 0) puts("Created T:tmpdir successfully"); else puts("Unable to create directory T:tmpdir"); } dice/_mods,_modu dice/_mods,_modu FUNCTION signed/unsigned long modulus 32 (DICE) DESCRIPTION These are assembly functions that DICE uses whenever it needs to do a long modulus. The functions are not callable from C. INPUTS D0 32 bit signed/unsigned integer D1 32 bit signed/unsigned integer RESULTS D0 Remainder of D0 divided by D1 SEE ALSO _divs, _divu, _muls, _mulu dice/_muls,_mulu dice/_muls,_mulu FUNCTION signed/unsigned long multiply (DICE) DESCRIPTION These are assembly functions that DICE uses whenever it needs to do long multiplication. They are not callable from C. INPUTS D0 32 bit signed/unsigned integer D1 32 bit signed/unsigned integer RESULTS D0 D0 multiplied by D1 SEE ALSO _divs, _divu, _mods, _modu dice/onbreak dice/onbreak FUNCTION Set special ^C handler (AmigaDOS) SYNTAX typedef int (*fptr)(); fptr oldfunc = onbreak(newfunc); fptr newfunc; DESCRIPTION onbreak sets a special function to handle ^C. It takes a pointer to this function and returns a pointer to the previous onbreak function, if any. When ^C is hit, the special onbreak function is called before any other action. If the onbreak function returns a non-zero value, ^C aborts the program like it usually does. If the function returns 0, however, the ^C is completely ignored. INPUTS newfunc pointer to function or NULL RESULTS fptr oldfunc; pointer to previous onbreak function SEE ALSO atexit EXAMPLE /* * Note: The reentrancy check is needed because of both * the puts and the sleep() call. */ #include <stdio.h> #include <stdlib.h> int brk() { static short cnt = 0; /* check for reentrancy */ if (cnt) /* if not 0 then reentered! */ return(0); ++cnt; puts("Nah Nah, you can't break me!"); sleep(1); --cnt; return(0); } int main() { short i; onbreak(brk); puts("Hit ^C while I loop from 1 to 100."); sleep(2); for (i = 1; i <= 100; ++i) printf("Loop, counting, count = %d\n", i); return(0); } dice/open dice/open FUNCTION open a file (UNIX) SYNTAX #include <fcntl.h> int fd = open(name, modes); char *name; int modes; DESCRIPTION open opens a file of the specified name using the specified modes. The combinations yield different results as described below: O_RDONLY : open file for reading only ----------+---------------------------------------------------------- O_WRONLY : open file for writing only ----------+---------------------------------------------------------- O_RDWR : open file for reading and writing ----------+---------------------------------------------------------- O_NDELAY : open file non-blocking (not implemented) ----------+---------------------------------------------------------- O_APPEND : open file for writing only and force all writes to : append to the file regardless of the current seek : position. open is a lower-level construct than the more : standard fopen. ----------+---------------------------------------------------------- O_CREAT creates the file if it does not exist; O_TRUNC truncates the file if it does exist; O_EXCL is used only with O_CREAT and if the file already exists the open will fail; O_BINARY opens the file for binary reading and writing, vs text. This flag is ignored by DICE since there is no difference on the Amiga. However, on Messy-DOS systems, CR-LF must be converted to an LF when reading text files. open returns a descriptor (>= 0) or error (< 0) on failure. || NOTE: Refer to the file_descriptor manual page for general || information. Unlike file pointers and file handles, the file || descriptor is checked for validity and will simply return an error || if illegal. INPUTS char *name; filename to open long modes; modes to open the file with RESULTS int fd; A file descriptor if >= 0, an error if < 0. SEE ALSO close, creat, fcntl, fdtofh, fopen, ioctl, isatty, lseek, mkdir, read, rmdir, unlink, write EXAMPLE #include <fcntl.h> #include <assert.h> main() { int fd, r; fd = open("T:xx", O_WRONLY|O_CREAT|O_TRUNC); assert(fd >= 0); close(fd); fd = open("T:xx", O_CREAT|O_EXCL|O_TRUNC|O_WRONLY); assert(fd < 0); /* will fail, file already exists */ remove("T:xx"); fd = open("T:xx", O_CREAT|O_TRUNC|O_WRONLY); assert(fd >= 0); /* will work */ write(fd, "FuBar-", 6); lseek(fd, 0L, 0); /* seek back to start of file */ r = write(fd, "XxXxx", 5); assert(r == 5); close(fd); fd = open("T:xx", O_APPEND|O_WRONLY); assert(fd >= 0); write(fd, "FuBar\n", 6); close(fd); printf("type t:xx should return \"XxXXX-FuBar\"\n"); return(0); } dice/perror dice/perror FUNCTION output error message associated with errno and text to stderr (ANSI) SYNTAX #include <stdio.h> void perror(str); const char *str; DESCRIPTION perror outputs the specified string, a colon, and the error number and error message associated with the current value of errno to stderr, ending with a newline. Using perror is a common way to generate error messages due to IO failures. INPUTS char *str; string message to include in error output EXAMPLE #include <stdio.h> main() { FILE *fp = fopen("T:DoesNotExist", "r"); if( fp ) { puts("T:DoesNotExist is not supposed to exist!"); exit(1); } perror("fopen"); return(0); } dice/PlaceRexxCommand dice/PlaceRexxCommand FUNCTION Send a command to ARexx (DICE) SYNTAX #include <lib/rexx.h> rc = PlaceRexxCommand(port, str, &res, &ec) struct MsgPort *port; char *str; char *res; long ec; DESCRIPTION PlaceRexxCommand sends an ARexx command off to ARexx. (compare to PlaceRexxCommandDirect which talks to an application) The command is normally a script file to run. You must specify the ARexx port that is to act as the default host port for the command or NULL to use DICE's default port. The default extension for the script is always the RexxHostName variable. Note that if you specify NULL for the port to use DICE's default, then you must have previously setup DICE's default port. This occurs automatically if RexxHostName was declared non-NULL, or manually if you had called Create[Global]DiceRexxPort(NULL, "name"). You supply the command in str which is passed to ARexx as Arg0. Currently there is no support for additional arguments. DICE will run the command synchronously and return the result code. The result string pointer will be set to either NULL or a malloc()'d string. If not NULL you are responsible for free()ing the result string when you are through with it!! If you wish to ignore any result you may pass NULL for this argument. The ec longword will be set to an internal ARexx error code... if the returned result code is non-zero and ec == 1 then ARexx was unable to find the specified ARexx command. You may pass NULL for this argument if you do not care about the error code. It is possible that your program will receive ARexx commands while it is waiting for the command you have sent to be returned. DICE will automatically call DoRexxCommand() from within the PlaceRexxCommand() routine when this case occurs. ARexx will set the error-code ec, which is different from the result-code. ec is set to 1 if the script could not be found. ARexx normally returns a severity code of 5 for this case. If the return code is 0 then ec will be 0. INPUTS struct MsgPort *port; Message port for processing. Typically you pass NULL to use the default port. char *str; String to be passed to ARexx for execution char **res; Pointer to place to store result string from ARexx. NULL indicates no result is desired. long *ec; Pointer to place to store error code from ARexx. Set to 1 for script not found. NULL indicates no result code desired. RESULTS int rc; Return code from ARexx SEE ALSO DoRexxCommand, PlaceRexxCommandDirect, ProcessRexxCommands EXAMPLE See DICE ARexx Support in chapter dice/PlaceRexxCommandDirect dice/PlaceRexxCommandDirect FUNCTION Send an ARexx command to an Application (DICE) SYNTAX #include <lib/rexx.h> rc = PlaceRexxCommandDirect(port, apport,str, &res, &ec); struct MsgPort *port; char *apport; char *str; char *res; long ec; DESCRIPTION PlaceRexxCommandDirect sends an ARexx command to a specification application (compare to PlaceRexxCommand which talks to ARexx directly). The command is normally a script file to run. You must specify the ARexx port that is to act as the default host port for the command or NULL to use DICE's default port. The default extension for the script is always the RexxHostName variable. Note that if you specify NULL for the port to use DICE's default, then you must have previously setup DICE's default port. This occurs automatically if RexxHostName was declared non-NULL, or manually if you had called Create[Global]DiceRexxPort(NULL, "name"). You supply the command in str which is made Arg0. Currently there is no support for additional arguments. DICE will run the command synchronously and return the result code. The result string pointer will be set to either NULL or a malloc()'d string. If you wish to ignore any result you may pass NULL for this argument. || NOTE: If you do not pass NULL, you are responsible for free()ing || the result string when you are through with it! The ec longword will be set to an internal ARexx error code... if the returned result code is non-zero and ec == 1 then ARexx was unable to find the specified ARexx command. You may pass NULL for this argument if you do not care about the error code. It is possible that your program will receive ARexx commands while it is waiting for the command you have sent to be returned. DICE will automatically call DoRexxCommand() from within the PlaceRexxCommand() routine when this case occurs. ARexx will set the error-code ec, which is different from the result-code. ec is set to 1 if the script could not be found. ARexx normally returns a severity code of 5 for this case. If the return code is 0 then ec will be 0. INPUTS struct MsgPort *port; Message port for processing. Typically you pass NULL to use the default port. char *apport; Name of application to send commands to. char *str; String to be passed to ARexx for execution char **res; Pointer to place to store result string from ARexx. NULL indicates no result is desired. long *ec; Pointer to place to store error code from ARexx. Set to 1 for script not found. NULL indicates no result code desired. RESULTS int rc; Return code from ARexx SEE ALSO DoRexxCommand, PlaceRexxCommand, ProcessRexxCommands EXAMPLE See DICE ARexx Support in chapter dice/pow,fpow dice/pow,fpow FUNCTION pow: return one double to the power of another (ANSI) fpow: return one float to the power of another (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = pow(b, bp); double bp; double b; float c = flog(d, dp); float dp; float d; DESCRIPTION pow returns one double to the power of another; fpow returns one float to the power of another. INPUTS double b; double floating point value (base) double bp; double floating point value (exponent) float d; float floating point value (base) float dp; float floating point value (exponent) RESULTS double a; double floating point value float c; float floating point value SEE ALSO acos, asin, atan, cos, exp, fabs, log, log10, pow, sin, sqrt, tan facos, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = pow(0.25, 4.0); printf("pow 0.25 ^^ 4.0 = %lf\n", a); /* 0.0039 */ } { /* less accuracy */ float a = fpow(0.25, 4.0); printf("pow 0.25 ^^ 4.0 = %lf\n", (double)a); } return(0); } dice/printf,fprintf,sprintf,vprintf,vfprintf,vsprintf FUNCTION formatted output to stdout, file pointer, or buffer (ANSI) SYNTAX #include <stdio.h> #include <stdarg.h> /* for v[f/s]printf() only */ int n = printf(fmt, ...); int n = fprintf(fp, fmt, ...); int n = sprintf(buf, fmt, ...); int n = vprintf(fmt, argvect); int n = vfprintf(fp, fmt, argvect); int n = vsprintf(buf, fmt, argvect); FILE *fp; char *fmt; char *buf; va_list argvect; DESCRIPTION These functions offer formatted printing in various flavors. printf and vprintf output to stdout; fprintf and vfprintf output to a file pointer (fp); sprintf and vsprintf output to a character buffer. All routines return the number of characters written if successful, a negative number if not. Only sprintf and vsprintf are limited in terms of output size (it cannot exceed the buffer you give it). The common argument to all routines is the format specifier. The format specifier is scanned to determine how to handle the arguments to the call (or the argument list for vfprintf/vsprintf). Characters are copied to the output until a % is encountered. %% indicates a literal '%' character. Otherwise, the % is followed by a control sequence that tells printf how to output the corresponding argument. The quantity is output and the scan continues until the end of the format string. The % formats are interpreted as follows: %[flags][#[.#]][modifier]<conversion-specifier> Items in brackets are optional. After the %, zero or more flags may be specified. Then, an optional integer which represents the minimum field width for the object may also be specified. If an integer is specified it may be followed by a period and another integer that represents that precision with which a number is printed. Zero or more modifiers may then be specified followed by a mandatory conversion specifier. Either or both integers (#[.#]) may be specified as a '*', as in "%*d", specifying that the minimum field width and/or precision is specified as an integer in the argument that occurs before the conversion object. For example, printf("--%*d--\n", 10, 23); would print the number 23 right justified in a field 10 characters wide. Conversion Flags ---------------- Minus (-) Left justify text within the field. <space> This flag places a blank in front of positive signed numbers, and a minus in front of negative numbers. This option allows columns of positive and negative numbers to line up. Plus (+) Cause a plus sign to be placed before a positive result. A minus sign is always placed before a negative result. Pound (#) Format output according to the type of input. e, E, f, F always retains the decimal point. g, G always retains the decimal point, and trailing zeros are kept. x and X print '0x' and '0X' respectively before the number (except that this is not currently implemented by DICE). 0 Pad columns with zeros instead of spaces. Ignored if a precision is specified or if the '-' flag is specified. Modifiers --------- h Indicates the corresponding integer argument is a short or an unsigned short (stands for "half-size"). Affects scanf(), but since DICE uses 32 bit integers, has no effect on printf(). l Indicates the corresponding integer argument is a long or unsigned long. Also indicates floating point argument is a double (else is a float). Under DICE this flag is superfluous for integers, but for portability reasons you want to specify it when an argument is explicitly a long. Conversion Specifiers --------------------- c Output integer as a character. d Output a signed integer. e Output a double quantity in exponential form. The precision specifies the number of digits beyond the decimal point to print, ie: [-]d.dddddde+/-dd. E Upper case version of e. f Output a double quantity. The precision specifies the number of digits beyond the decimal point to print, ie: [-]d.dddddd g Output a double quantity using either the 'e' or 'f' form, depending on the exponent. G Output a double quantity using either the 'E' or 'f' form, depending on the exponent. i Same as 'd', but less portable. n The argument is a pointer to an integer which is used to set the integer to the bytes written out so far. This is especially useful with sprintf to determine where a particular part of the format begins in the output buffer. o The unsigned integer quantity is converted to ASCII-octal. p The pointer is printed (basically the hexadecimal address is printed). s The NULL-terminated string represented by the character pointer is printed. u The unsigned integer quantity is converted to ASCII-decimal. x The unsigned integer quantity is converted to ASCII-hex using '0'-'9', 'a'-'f'. X The unsigned integer quantity is converted to ASCII-hex using upper case 'A'-'F' instead of lower case. INPUTS FILE *fp; file pointer (fprintf, vfprintf) char *fmt; format string, e.g. "Answer is %d\n" char *buf; buffer (sprintf, vsprintf) va_list argvect; arg list (vprintf, vfprintf, vsprintf) RESULTS int n; Number of characters written if successful, a negative number if not. For sprintf and vsprintf the NULL character at the end of the string is NOT included in the count. SEE ALSO puts, fputs, fwrite EXAMPLE /* ** Example using most printf conversion specifiers. ** Compile with -lm for the math functions to operate. */ #include <stdio.h> #include <stdarg.h> void test_varargs(); /* Always use function prototypes */ main() { char buf[256]; int n, i; printf( "Normal: ab%c %03d %03o $%p Fu%s %u $%x $%8X $%08lX\n", 'c', 43, 11, buf, "Bar",32094,4095,4095,4095 ); printf( "Math: Double: %le Float: %lf Formatted Float: %2.2lf\n", 1.23E-2, 1.23E-2, 1.257 ); printf("%9s\n", "<-"); /* Specify 9 character field width */ printf("%*s\n", 9, "<-"); /* Indirect specification */ n = sprintf(buf, "Save %n%s", &i, "the whales"); puts(buf); printf("String is %d+1 bytes long," /* String Concatenation */ "with a %%n token at %d.\n", n, i); fprintf(stdout, "\nThis is a call to %s\n", "fprintf"); test_varargs("%d %d %d ", 1, 2, 3); return(0); } void test_varargs(ctl, ...) char *ctl; { va_list va; int n; va_start(va, ctl); n = vprintf(ctl, va); printf("<- %d chars written\n", n); va_end(va); } dice/ProcessRexxCommands dice/ProcessRexxCommands FUNCTION Handle incomming ARexx commands (DICE) SYNTAX #include <lib/rexx.h> ProcessRexxCommands(port) struct MsgPort *port; DESCRIPTION In order to process incomming ARexx commands you must call ProcessRexxCommands when you receive the signal RexxSigBit (signal mask is (1 << RexxSigBit)). Passing NULL to this routine will cause DICE to scan ALL KNOWN ARexx ports belonging to this program... that is, the master port and all created ports. DICE will call DoRexxCommand for each ARexx command received as well as weed out returned messages from any ARexx commands we have sent that are still in progress. If you wish, you can pass a specific message port to have DICE only process ARexx commands received on a specific port, but beware that your Wait on the signal bit has cleared the signal and you should be sure to process all message ports before calling Wait again, else risk leaving unprocessed ARexx messages queued in and then blocking in Wait. INPUTS struct MsgPort *port; Message port to process or NULL to process all ports. SEE ALSO DoRexxCommand, PlaceRexxCommand, PlaceRexxCommandDirect EXAMPLE See DICE ARexx Support in chapter dice/putchar dice/putchar FUNCTION output character to stdout (ANSI) SYNTAX #include <stdio.h> int r = putchar(c); /* MACRO */ DESCRIPTION putchar outputs a character to stdout, returning the output character unless an error occurred. If an error occurred then EOF is returned. || NOTE: Refer to the file_pointer manual page for general || information. INPUTS int c; character to output, 0 to 255 RESULTS int r; same as c unless error occurred in which case EOF. SEE ALSO putc, fputc, fread, fwrite, getc, getchar EXAMPLE /* * copy stdin to stdout using getchar/putchar. Normally * one uses fread/fwrite, but I'll save that for the * fread manual page. Note that I output the initial * message to stderr so it does not get stuck into stdout * in case the user has redirected stdout. * * See getc manual page for equivalent example using * getc/putc */ #include <stdio.h> main() { int c; fputs("Type a couple of lines, then ^\\ (EOF)\n", stderr); while ((c = getchar()) != EOF) { putchar(c); } return(0); } dice/qsort dice/qsort FUNCTION sort an array of objects (ANSI) SYNTAX #include <stdio.h> #include <stdlib.h> (void) qsort(array, numElem, elemSize, compare_func) void *array; size_t numElem; size_t elemSize; int (*comp_func)(const void *arg1, const void *arg2); DESCRIPTION qsort sorts numElem elements in an array based at array. Each element is elemSize bytes long. When a comparison is required, qsort calls the passed compare_func function pointer with a pointer to the two elements being sorted. DICE currently implements qsort with a simple merge sort algorithm, using relatively slow movmems to avoid having to allocate much additional storage. Very little stack is used. Traditional qsort employs a stack based quick-sort algorithm that might use a massive amount of stack. INPUTS void *array; pointer to base of array of objects size_t numElem; number of elements in the array size_t elemSize; size, in bytes, of each element int (*comp_func)() function pointer to compare function given pointers to two of the elements EXAMPLE #include <stdio.h> #include <stdlib.h> #define NUM_GENIUS 8 char *StrList[NUM_GENIUS] = { "Euler", "Einstein", "Pascal", "Zeno", "Godel", "Leibniz", "Euclid", "Von Neumann" }; my_comp(s1, s2) char **s1; char **s2; { return(strcmp(*s1, *s2)); } main() { short i; qsort(StrList, NUM_GENIUS, sizeof(char *), my_comp); for (i = 0; i < NUM_GENIUS; ++i) printf("%d %s\n", i, StrList[i]); return(0); } dice/raise dice/raise FUNCTION raise a signal (cause an 'interrupt' synchronously) (ANSI) SYNTAX int r = raise(signo); int signo; DESCRIPTION raise causes a signal to occur and the appropriate action to be taken. It returns 0 on success, -1 if the signo is invalid (outside the range of allowed signals). When you raise a signal, the signal is set back to its default vector before the handler is called. Thus, if you are allowing multiple signals to occur you MUST restore the signal vector with signal from your signal handler before it returns. INPUTS int signo; signal to cause RESULTS int r; 0 on success, -1 if signo is out of range. SEE ALSO signal EXAMPLE /* * prints the numbers 0 to 99, except only gets * to 50 because we 'cause' a ^C. */ #include <signal.h> main() { short i; for (i = 0; i < 100; ++i) { printf("i = %d\n", i); if (i == 50) raise(SIGINT); } return(0); } dice/rand dice/rand FUNCTION return pseudo-random number (ANSI) SYNTAX #include <stdio.h> #include <stdlib.h> int n = rand(void); (void) srand(seed) unsigned int seed; DESCRIPTION rand returns a random number as a positive integer ranging from 0 to RAND_MAX. RAND_MAX is defined in stdlib.h and is at least 32767. DICE implements it as 2147483647 == 0x7FFFFFFF. The initial seed used to generate the pseudo-random sequence is 1, but may be reinitialized to any number you desire using srand. rand is guaranteed to return the same sequence for the same seed. INPUTS none RESULTS int n; returned by rand(), this number will be a positive integer. SEE ALSO srand EXAMPLE #include <stdio.h> #include <stdlib.h> main(int ac, char**av) { short i; short j; if (ac == 2) { int seed = strtol(av[1], NULL, 0); srand(seed); printf("using seed = %d\n", seed); } else puts("using seed = 1"); for (i = 0; i < 10; ++i) { int n = rand(); printf("Random number: %08lx\t(%d)\n", n, n); } for (i = 0; i < 31; ++i) { int isone = 0; long mask = 1 << i; for (j = 0; j < 32767; ++j) { if (rand() & mask) ++isone; } printf("bit %d %5d:%-5d (deviation %d)\n", i, 32767 - isone, isone, 16384 -isone); } return(0); } dice/read dice/read FUNCTION read data from a file (UNIX) SYNTAX #include <fcntl.h> int r = read(fd, buf, bytes); int fd; void *buf; int bytes; DESCRIPTION read reads data from a file starting at the current seek position. read returns the number of bytes read or -1 if a read error occurs. With normal files, read will always return the number of bytes requested until the end of file is reached, in which case read may return fewer than the number of bytes requested. If at the end of a file, read will return 0. With devices read may or may not return the number of bytes requested depending on the device. || NOTE: Refer to the file_descriptor manual page for general || information Unlike file pointers and file handles, the file || descriptor is checked for validity and will simply return an error || if illegal. INPUTS int fd; file descriptor to read from void *buf; pointer to buffer to read data into int len; maximum number of bytes to read RESULTS int r; number of bytes actually read (could be less than len or 0), or < 0 if error. SEE ALSO close, creat, fcntl, fdtofh, ioctl, isatty, lseek, mkdir, open, read, rmdir, unlink, write EXAMPLE #include <fcntl.h> #include <assert.h> main() { int fd; int r; char buf[32]; fd = open("T:xx", O_WRONLY|O_CREAT|O_TRUNC); assert(fd >= 0); write(fd, "FuBar\n", 6); close(fd); fd = open("T:xx", O_RDONLY); assert(fd >= 0); r = read(fd, buf, sizeof(buf)); /* sizeof(buf)==32 */ close(fd); assert(r == 6); /* * note that the buffer is not terminated with * a NULL, but since we are using write() which * requires a length it does not matter */ write(1, buf, r); } dice/realloc dice/realloc FUNCTION reallocate memory allocated by calloc, malloc, or strdup (ANSI) SYNTAX #include <stdlib.h> void *newptr = realloc(oldptr, bytes) void *oldptr; size_t bytes; DESCRIPTION realloc reallocates a previously allocated buffer, making it larger or smaller. It returns a pointer to a new buffer which might be the same as the old buffer, but might not. Data in the original buffer is copied to the new buffer and the original buffer is freed. When extending a buffer with realloc note that the extended bytes (beyond the original buffer) will come up garbage. You may pass a NULL as the first argument to realloc which basically makes realloc a malloc. INPUTS void *oldptr; pointer to original allocated buffer size_t bytes; size of new buffer RESULTS void *newptr; pointer to new buffer SEE ALSO malloc, calloc, strdup EXAMPLE #include <string.h> #include <assert.h> #include <stdlib.h> main() { char *s; int len; s = strdup("This is a test"); assert(s); len = strlen(s); /* * Remember that len does not include the NULL * byte at the end of the string */ s = realloc(s, len + 8); /* make more room */ assert(s); /* * we can use strcat since in extending the * allocated string the NULL *was* copied along * with the string during the realloc. */ strcat(s, "xx"); puts(s); /* This is a testxx */ return(0); } dice/rega4 dice/rega4 FUNCTION return current contents of register A4 (DICE) SYNTAX char *basePtr = rega4(); DESCRIPTION rega4 is not geta4; rega4 simply returns the current contents of the A4 register when you need it. Note that DICE offsets the A4 register 32766 from the actual small-data base so as to be able to use the entire -32768 to 32767 range to access 64 kilobytes of small-data. Note that a rega4 call inside a subroutine qualified with __geta4 is guaranteed to return the data base pointer. Also, a rega4 call from any subroutine not called from an interrupt or a call back will return the proper data base pointer. ## WARNING: Programs which use this function will not be able to be ## made resident. dice/remove dice/remove FUNCTION delete a file (ANSI) SYNTAX #include <stdio.h> int error = remove(filename); const char *filename; DESCRIPTION remove deletes the specified file path returning 0 on success, a negative number on failure. On the Amiga, an error will occur if you try to delete a file currently opened by yourself or any other process. remove is an ANSI function. unlink does the same thing but is a UNIX-compatible function. INPUTS char *filename; filename to delete RESULTS int error; 0 on success, a negative number on failure SEE ALSO unlink EXAMPLE #include <stdio.h> main() { int error = remove("T:XXX"); if (error < 0) { perror("remove(\"T:XXX\") failed"); exit(1); } puts("T:XXX has been deleted"); return(0); } dice/rename dice/rename FUNCTION rename a file, or move a file from one directory to another on the same filesystem (ANSI) SYNTAX #include <stdio.h> int error = rename(origname, newname); const char *origname; const char *newname; DESCRIPTION rename renames a file. You may also use rename to move a file (and rename at the same time) to another directory on the same filesystem. rename returns 0 on success, a negative number on failure. INPUTS const char *origname; existing file const char *newname; new filename and/or path RESULTS int error; 0 on success, a negative number on failure SEE ALSO rewind EXAMPLE /* * create the file T:xxjunk and the directory * T:junkdir then move T:xxjunk into T:junkdir * and rename to T:yyjunk at the same time. * As is aptly demonstrated by this example, some * errors are not really errors. For example, * mkdir where the dir already exists is not usually * an error. */ #include <stdio.h> #include <assert.h> #include <errno.h> main() { FILE *fp; int error; error = mkdir("T:junkdir"); if (error < 0 && errno != EEXIST) perror("mkdir"); fp = fopen("T:xxjunk", "w"); if (fp == NULL) { perror("fopen"); exit(1); } fprintf(fp, "This was originally T:xxjunk!\n"); fclose(fp); error = rename("T:xxjunk", "T:junkdir/yyjunk"); if (error < 0) perror("Error renaming T:xxjunk"); else puts("rename succeeded, look in T:junkdir"); return(0); } dice/rewind dice/rewind FUNCTION seek filepointer to beginning of file (ANSI) SYNTAX #include <stdio.h> void rewind(fp); FILE *fp; DESCRIPTION rewind rewinds the file to the beginning, equivalent to fseek(fp, 0L, 0);. || NOTE: Refer to the file_pointer manual page for general || information. INPUTS FILE *fp; file pointer to rewind SEE ALSO fseek, fgetpos, fsetpos EXAMPLE /* print a file 3 times */ #include <stdio.h> main(int ac, char**av) { FILE *fp; int i; char buf[256]; if (ac == 1) { puts("Expected textfile argument"); exit(1); } fp = fopen(av[1], "r"); if (fp == NULL) { printf("Unable to open %s\n", av[1]); exit(1); } for (i = 1; i <= 3; ++i) { rewind(fp); printf("PRINTING #%d\n", i); while (fgets(buf, sizeof(buf), fp)) fputs(buf, stdout); } return(0); } dice/rmdir dice/rmdir FUNCTION delete a directory (UNIX) SYNTAX #include <stdio.h> int r = rmdir(dirname); char *dirname; DESCRIPTION rmdir deletes a directory. The directory must be empty for the deletion to work. On the Amiga this call is equivalent to remove or unlink. INPUTS char *dirname; name of directory to delete RESULTS int r; 0 if successful, non-zero if error SEE ALSO mkdir EXAMPLE #include <assert.h> main() { int r; r = mkdir("T:tmpdir"); assert(r == 0); r = rmdir("T:tmpdir"); assert(r == 0); } dice/scanf,fscanf,sscanf dice/scanf,fscanf,sscanf FUNCTION scan formatted text and convert to variables (ANSI) SYNTAX #include <stdio.h> int n = scanf(ctl, ...); /* Input: standard in */ int n = fscanf(fp, ctl, ...); /* Input: file pointer */ int n = sscanf(str,ctl, ...); /* Input: string buffer */ const char *ctl; FILE *fp; char *str; DESCRIPTION These functions scan the specified input file or buffer for fields matching those specified by the control field. Commands starting with % relate the scanned text to a list of pointers. The values the pointers point to are updated (say that three times fast). Other characters in the control field must match the scanned text exactly, except for white space characters, which match any length of white space in the scanned text. Control Field Commands ---------------------- The control field command format is as follows: %[*][nnn][h/l/L]<conversion-specifier> % All conversion specifiers start with %. Use %% to match a single % in the source text. * An optional * tells scanf to perform the conversion, but discard the result. Do not include a destination pointer for skiped conversions. nnn An optional decimal number is used for string conversion to specify a maximum field width. h The modifier h specifies the destination should be treated as a short integer rather, than an integer. The h conversion applies to d, i, n, o, u, x and X. l The modifier l specifies the destination should be treated as a long integer, rather than an integer. The l conversion applies to d, i, o, u, x and X. L When used with formats e, f or g, specifies the destination should be treated to a long double rather than a double. Conversion Specifiers --------------------- c With no field width specified, converts one character. With a field width, converts the number of characters specified by the field width into an array. The expected argument is a pointer to a character or array of characters. No white space is skipped. d Converts a decimal (base 10) number. The expected argument is a pointer to an integer. The l and h modifiers may be used to specify either a long or short integer result. e/f/g Scans a floating point number. If the l modifier is used, a long double pointer is expected (not implemented in DICE yet), else a double is expected. i Converts a number to an integer. The format should be equivalent to that expected by strtol with a base argument of 0 (automatic detection of format). n This command does not scan any text. It places into an integer the current count of processed characters. o An octal number is expected. The value is stored to an integer. p A pointer is expected, in the same format as the %p from printf. The value is stored into a pointer, passed as void ** (a pointer to any type of pointer). s Reads a string of non-white space characters and copies into the array specified by the argument. The argument must be of type char * and have enough space to handle any possible string plus a NULL terminator. x A hexadecimal (base 16) number is expected. The value is stored into an integer. This is equivalent to calling strtol with a base of 16. %% Match a single % in the input stream. [...] Scan a scanset. Scan the input stream and place the characters into a char * buffer until a character is read that does not match the scanset. If a scan set begins with ^ (as in [^abcd]) then all characters are allowed except those specified in the scanset. If a scanset begins as []abcd] or [^]abcd] then the ']' character is included in the scan set and the set is terminated by ']'. || NOTE: All scanf arguments are pointers. A common mistake is || to pass arguments directly; pointers are required. All || floating point arguments must be pointers to doubles. INPUTS char *ctl; format control string, containing % commands FILE *fp; file pointer for fscanf char *str; string pointer for sscanf ... pointers to variables ready to receive conversions. RESULTS int n; Number of conversions that occurred or -1 if no conversions could be made (this usually means EOF). The function may return less than the number of requested conversions. This value does not count any %* conversions. SEE ALSO sprintf, printf, fprintf, strtol EXAMPLE #include <stdio.h> main(int ac, char**av) { int n, integer; n = sscanf("Input: 132\n", "Input: %ld\n", &integer); printf("First test: n=%d integer=%d ", n, integer); short a[3] = {-1, -2, -3}; // Unscanned arguments are NOT int b[3] = {-4, -5, -6}; // cleared - they retain char buf1[11], buf2[11]; // former values! buf1[0]=buf2[0]=buf2[10] = 0; if (ac != 2) { puts("Expected string to format!"); exit(1); } n = sscanf(av[1],"%hd %ho %hi %*d %X %n%10s %10c -%d-", a+0,a+1,a+2, b+0,b+1,buf1,buf2,b+2); printf("Second test: %d elements\n", n); printf("a (shorts): %d %d %d\n", a[0], a[1], a[2]); printf("b (ints) : %d %d %d\n", b[0], b[1], b[2]); printf("buf1 : %s\nbuf2 : %s\n", buf1, buf2); return(0); } /* scanf "100 100 0x100 200 0x300 reduce reuse recycle!" ** First test: n=1 integer=132 Second test: 6 elements ** a (shorts): 100 64 256 ** b (ints) : 768 24 -6 ** buf1 : reduce ** buf2 : reuse recy */ dice/setbuf,setvbuf dice/setbuf,setvbuf FUNCTION change a file pointer's buffering (ANSI) SYNTAX #include <stdio.h> void setbuf(fp, buf); error = setvbuf(fp, buf, mode, size); FILE *fp; char *buf; int mode; size_t size; int error; DESCRIPTION setbuf changes the internal buffer used by stdio. The buffer you pass it must be BUFSIZ bytes in size. You can set a file pointer to unbuffered by passing NULL for your buffer. setvbuf supersedes this call and is, in general, a better function. Type type argument must be one of _IOFBF (Fully Buffered), _IOLBF (Line Buffered) or _IONBF (Non Buffered). For use with DICE it is best to supply a buffer size, but a NULL buf pointer. DICE will allocate buffers as they are needed. ## WARNING: If buffering is turned off for a file pointer ## representing a console device, the console device is set to ## unbuffered as well. If buffering is turned on for a file pointer ## representing a console device, the console device is set to ## buffered as well. || NOTE: Refer to the file_pointer manual page for general || information. INPUTS FILE *fp; file pointer to affect. char *buf; buffer for use by the file pointer, or NULL. int type; (setvbuf) type of buffering. size_t size; (setvbuf) requested buffer size or zero. int error; (setvbuf) error code (if size or type are invalid). EXAMPLE 1 #include <stdio.h> main() { FILE *fp; fp = fopen("CON:0/0/640/100/DICE Setbuf Test","w"); if(! fp ) exit( 10 ); fprintf(fp, "This will be buffered, "); sleep(2); setvbuf(fp, NULL, _IONBF, 0); fprintf(fp, "yet these will print immediately "); sleep(2); fprintf(fp, "(we are unbuffered)."); sleep(4); fprintf(fp, "\n"); setvbuf(fp, NULL, _IOLBF, 128); fprintf(fp, "Now back to buffered... "); sleep(2); fprintf(fp, "(See - you had to wait).\n"); sleep(8); fclose( fp ); return(0); } EXAMPLE 2 #include <stdio.h> #define BUFFER_SIZE 128 main() { int c; char buf[256]; setvbuf(stdin, NULL, _IONBF, 0); printf("Type a character: "); fflush(stdout); c = getchar(); printf("c = %d\n", c); setvbuf(stdin, NULL, _IOLBF, BUFFER_SIZE); printf("Type a line: "); fflush(stdout); fgets(buf, sizeof(buf), stdin); printf("You said : %s\n", buf); return(0); } dice/setjmp,longjmp dice/setjmp,longjmp FUNCTION setjmp: save procedure context for future long jump (ANSI) longjmp: jump to a previously saved procedure context (ANSI) SYNTAX #include <setjmp.h> int r = setjmp(enviro); (void) longjmp(enviro, rval) jmp_buf enviro; int rval; DESCRIPTION First, setjmp stores the current procedure context into an environment array whose type is jmp_buf. When called by a procedure it saves the environment and returns 0. Then when called, longjmp jumps to a previously saved environment causing execution to begin at the setjmp call that saved that environment. Yet instead of returning 0 the 'resumed' setjmp returns a return value set by the longjmp call. Jmp_buf is a typedef of an array, thus by passing a jmp_buf structure we really pass the address of it. setjmp and longjmp are fully compatible with dynamic stacks (-gs option to DCC). :: Beginner's Note: setjmp and longjmp should be used sparingly, if :: at all. They make code hard to understand, are rife with potential :: for adding bugs and are considered even uglier than the C goto :: statement. In the example below main is still stacked when the longjmp occurs and is thus valid. It would be illegal, for instance, to call a subroutine which does a setjmp and RETURNS to you, then longjmp back to that subroutine. The contents of the jmp_buf structure are private and may not be modified by the program. ## WARNING: You can only longjmp to a previously saved environment ## that has not been unstacked. WARNING: setjmp saves the current ## state of the registers, but not any registers that get modified ## between the setjmp and the longjmp! Thus, auto variables placed in registers (which is done so automatically under DICE) may contain 'old' values after a longjmp if they were modified after the setjmp. To prevent this such variables must, by ANSI convention, be made volatile. The volatile qualifier forces an auto variable to be placed on the stack instead of in a register. INPUTS jmp_buf enviro; environment structure int rval; return value (longjmp call) RESULTS (setjmp) int r; 0 when called directly, rval when environment restored by a longjmp SEE ALSO onbreak, signal EXAMPLE #include <stdio.h> #include <setjmp.h> jmp_buf x; int brk(void); void breakme(void); main() { int r; onbreak(brk); r = setjmp(x); // returns 0 when called by main puts("\nArnie sez: I'll be back..."); if (r == 0) for (;;) breakme(); printf("Broke and jumped, r = %d\n", r); return(0); } /* even though the onbreak call is supposed to return, ** we can longjmp out of it as well. */ int brk() { longjmp(x, 23); } void breakme() { puts("Break Me With ^C!"); } dice/signal dice/signal FUNCTION set a signal vector for a signal (ANSI) SYNTAX #include <signal.h> typedef void (*__sigfunc)(int); __sigfunc oldfunc = signal(signo, newfunc) int signo; __sigfunc newfunc; DESCRIPTION signal sets a signal vector function for a given signal number as defined in <signal.h> and returns the previously set function. Currently only SIGINT causes any semi-asynchronous action to occur. You may pass newfunc as your own signal function or one of: SIG_ERR error (exit program) SIG_DFL default (for break, normal operation) SIG_IGN ignore signal (for break, ^C is now ignored) when a signal occurs, the signal is set back to its default condition before the handler is called. Thus, if you are allowing multiple signals to occur you must restore the signal vector with signal from your signal handler before it returns. || NOTE: On the Amiga, signals are not truly asynchronous. ^C is || detected during stdio calls only. No other signal is || implemented though you CAN modify any signal vector 0 to 31 || and raise it with the raise call. Early versions of DICE, || including quite possibly this version, do not understand || complex type declarations containing procedural types. Thus, || you may have to get around the problem by building up a || complex procedural type with typedefs. Unlike onbreak, a || signal function returns no value. INPUTS int signo; signal to modify, usually SIGINT __sigfunc newfunc; signal function or SIG_ERR, SIG_DFL, SIG_IGN RESULTS __sigfunc oldfunc; previous signal function SEE ALSO raise EXAMPLE #include <signal.h> void brkfunc(int); main() { short i; puts("The following is unbreakable"); sleep(1); signal(SIGINT, SIG_IGN); for (i = 0; i < 100; ++i) printf("1 %d\n", i); puts("The following may be broken out of"); puts("with a cute message"); sleep(1); signal(SIGINT, brkfunc); for (i = 0; i < 100; ++i) printf("2 %d\n", i); puts("The following may be broken out of"); sleep(1); signal(SIGINT, SIG_DFL); for (i = 0; i < 100; ++i) printf("3 %d\n", i); puts("Hey! You never hit ^C! \ What kind of test is this!"); return(0); } void brkfunc(int signo) { printf("signo %d. Want cute? Get a kitten.\n", signo); exit(1); } dice/sin,fsin dice/sin,fsin FUNCTION sin: return sine of a double quantity (ANSI) fsin: return sine of a float quantity (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = sin(b); double b; float c = fsin(d); float d; DESCRIPTION sin returns the sine of a double quantity; fsin returns the sine of a floating point quantity. These functions use radian measure ("rad" on your calculator). INPUTS double b; double floating point value float d; float floating point value RESULTS double a; result double floating point value float c; result float floating point value SEE ALSO acos, asin, atan, cos, exp, fabs, log, log10, pow, sqrt, tan, facos, fasin EXAMPLE See cos for an example. dice/sleep dice/sleep FUNCTION sleep for a period of time (UNIX) SYNTAX #include <stdio.h> sleep(n); int n; DESCRIPTION The sleep function waits for a period of time specified in seconds. It can be interrupted by a ^C. || NOTE: The timekeeping of sleep is not very accurate. On the || Amiga, sleep is implemented with a loop of delay(50); calls. INPUTS int n; number of seconds to sleep EXAMPLE #include <stdio.h> main(int ac, char**av) { puts("Sleeping for 10 seconds"); sleep(10); puts("That was a good rest"); return(0); } dice/sqrt,fsqrt dice/sqrt,fsqrt FUNCTION sqrt: return the square root of a double (ANSI) fsqrt: return the square root of a float (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = sqrt(b); double b; float c = fsqrt(d); float d; DESCRIPTION sqrt returns the square root of a double quantity; fsqrt returns the square root of a floating point quantity. INPUTS double b; double floating point value float d; float floating point value RESULTS double a; double floating point value float c; float floating point value SEE ALSO acos, asin, atan, cos, exp, fabs, log, log10, pow, sin, tan, facos, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = sqrt(0.25); printf("sqrt 0.25 = %lf\n", a); /* 0.5000 */ } { /* less accuracy */ float a = fsqrt(0.25); printf("sqrt 0.25 = %lf\n", (double)a); } return(0); } dice/srand dice/srand FUNCTION set seed for pseudo-random number (ANSI) SYNTAX #include <stdio.h> #include <stdlib.h> (void) srand(seed) unsigned int seed; DESCRIPTION srand initializes the seed for function rand. INPUTS unsigned int seed; an unsigned integer used to seed the pseudo-random number generator via srand. SEE ALSO rand EXAMPLE See the "rand" manual page for an example dice/stack_abort dice/stack_abort FUNCTION exit point when dynamic stack allocation fails (DICE) SYNTAX void stack_abort(void) { /* .. your exit code .. */ abort(); } DESCRIPTION When dynamic stack allocation is enabled via the -gs option and such an allocation fails, stack_abort is called. If you do not specify a stack_abort routine, the c.lib stack_abort function will simply call abort. If you do specify a stack_abort routine, you have two choices: you can exit out of the program, or you can simply return from the subroutine which retries the allocation and calls stack_abort again if it fails (perhaps wait a bit in hopes memory has become available). The program has about 2KB of stack left at the time this function is called. Since a low memory condition exists when this function is called you should not do anything that might require additional allocations! SEE ALSO abort, exit dice/stat dice/stat FUNCTION stat a file by name (UNIX) SYNTAX #include <sys/stat.h> int error = stat(name, &stat_buf); const char *name; struct stat stat_buf; DESCRIPTION stat is a UNIX-compatible call that returns information pertaining to the file represented by its name. If 0 is returned, stat succeeded and the fields will be filled in as follows: st_mode Flags S_IFDIR if directory, S_IFREG if regular file, S_IREAD if readable, S_IWRITE if writable, S_IEXEC if executable. st_size Size of the file, in bytes. st_blksize Always returns 512 (for now). st_blocks A guess at the number of actual blocks the file takes up, including headers and side sectors. st_ctime Time the file was last modified. st_mtime Same as st_ctime. st_dev Physical device ID (do not try to interpret this field, but it does represent the DOS handler). st_ino inode ID (usually a file block number on the Amiga). || NOTE: On the Amiga one normally cannot directly examine a file || that is exclusively locked. If this case occurs, stat will || attempt to scan the parent directory for the file and if that || doesn't work, returns -1. INPUTS char *name; name of file to stat struct stat *sbuf; address of stat structure that will be filled in RESULTS int error; 0 on success, < 0 on error SEE ALSO chdir EXAMPLE #include <stdio.h> #include <fcntl.h> #include <sys/stat.h> main(int ac, char**av) { int r; struct stat stat_buf; if (ac == 1) { puts("Expected a test file name"); exit(1); } r = stat(av[1], &stat_buf); if (r < 0) printf("Can't stat %s\n", av[1]); else { printf("File is %d bytes long\n", stat_buf.st_size); printf("modified %s", ctime(&stat_buf.st_ctime)); } return(0); } dice/stdin,stdout,stderr,EOF dice/stdin,stdout,stderr,EOF FUNCTION stdin: standard input channel (file pointer - MACRO) stdout: standard output channel (file pointer - MACRO) stderr: standard error channel (file pointer - MACRO) EOF: special value representing End-Of-File SYNTAX #include <stdio.h> DESCRIPTION stdin is the name for the program's standard input stream, a "FILE *" (Pointer to structure FILE). This can be redirected via command line redirection when the program is run. stdout is a FILE * type that represents the program's standard output stream. This can also be redirected via command line redirection when the program is run. stderr is a FILE * type that represents the program's standard error stream. Currently stderr is opened by _main and represents the console device associated with the program regardless of standard redirections. EOF is special value, -1 in this implementation, that represents an end of file marker. Functions that return a single character actually return type int to allow EOF to be distinct from valid characters. Include the file stdio.h to use these definitions. These file pointers may be fclose'd or freopen'd at any time. The stdio macros getchar and putchar and stdio library routines gets and puts deal with stdin and stdout respectively while other library routines such as perror output to stderr. dice/stpchr dice/stpchr FUNCTION Search for a character in a string (UNIX) SYNTAX #include <string.h> char *ptr = stpchr(s, c) const char *s; int c; DESCRIPTION This searches for the character c within the string pointed to by s. The terminating NULL at the end of s is NOT included in the search. A pointer to the first occurrence of c in s is returned or NULL if c could not be found. c is converted to a char by stpchr before beginning the search. || NOTE: It is better to use the ANSI standard strchr and strrchr || functions. INPUTS char *s; pointer to string to search int c; character to search for RESULTS char *ptr; pointer to the first occurrence of the character c in s, or NULL if c could not be found in s. SEE ALSO strchr, strrchr EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { char *s = "this is a test"; char *ptr; ptr = stpchr(s, 'i'); assert(ptr == s + 2); puts(ptr); /* "is is a test" */ return(0); } dice/stpcpy dice/stpcpy FUNCTION copy a string returning a pointer to the end of the destination (UNIX) SYNTAX #include <string.h> char *ptr = stpcpy(d, s); char *d; char *s; DESCRIPTION This function copies the NULL terminated string pointed to by s to the buffer d. The NULL is copied. A pointer to the NULL character at the end of the copied string in d is returned. || NOTE: stpcpy is non-standard. While a stpcpy/stpcpy combination || is more efficient than a strcpy/strcat combination, strcpy and || strcat are standard functions and thus are guaranteed to exist in || all environments. INPUTS char *d; pointer to beginning of destination buffer char *s; pointer to beginning of source string RESULTS char *ptr; pointer to end of data copied to destination buffer SEE ALSO strcpy, strbpl EXAMPLE #include <stdio.h> #include <string.h> main() { char *buf1 = "Micky "; char *buf2 = "Moose"; char dest[32]; char *ptr; ptr = stpcpy(dest, buf1); stpcpy(ptr, buf2); puts(dest); /* Micky Moose */ return(0); } dice/strbpl dice/strbpl FUNCTION unpack a string-array buffer into an array of pointers (DICE) SYNTAX #include <string.h> int num = strbpl(av, max, sary) char **av; int max; const char *sary; DESCRIPTION strbpl unpacks a string-array into an array of string pointers. The string array is a series of NULL terminated strings strung together and terminated by a final NULL. A pointer to each string is placed in the array-of-pointers (av) with a final NULL entry assuming the number of strings does not exceed (max-1). INPUTS char **av; pointer to a preallocated array of pointers int max; the maximum number of entries in the above array char *sary; pointer to a packed string. RESULTS int num; number of pointers loaded into the av array not including the final NULL. If num == max then the av array was not large enough to fit all the strings or the final NULL. EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { char *sary = "this\0is\0a\0test\0\0"; char *av[16]; int n; #define arysize(x) (sizeof(x)/sizeof((x)[0])) n = strbpl(av, arysize(av), sary); assert(n == 4); /* n == 4 */ puts(av[0]); /* this */ puts(av[1]); /* is */ puts(av[2]); /* a */ puts(av[3]); /* test */ assert(av[4] == NULL); /* av[4] == NULL */ return(0); } dice/strcat dice/strcat FUNCTION concatenate a string to an existing string (ANSI) SYNTAX #include <string.h> char *d = strcat(d, s); char *d; const char *s; DESCRIPTION strcat scans the destination buffer for the NULL terminator and then appends the source string to the destination buffer (removing the NULL terminator and placing one at the end after the concatenation). A pointer to the beginning of the destination buffer is returned. INPUTS char *d; pointer to destination buffer which already contains a string (which could be just a \0). char *s; pointer to the NULL terminated source string RESULTS char *d; same as the first argument, a pointer to the destination buffer. SEE ALSO strncpy, strcpy, strncat EXAMPLE #include <stdio.h> #include <string.h> main() { char dest[80]; char *s1 = "I had an elegant proof also, "; char *s2 = "but the console window was too narrow..."; strcpy(dest, s1); puts( strcat(dest, s2) ); /* returns its first arg */ } dice/strchr dice/strchr FUNCTION search for a character in a string (ANSI) SYNTAX #include <string.h> char *ptr = strchr(s, c) const char *s; int c; DESCRIPTION This searches for the character c within the string pointed to by s. The terminating NULL at the end of s is included in the search. A pointer to the first occurrence of c in s is returned or NULL if c could not be found. C is converted to a char by strchr before beginning the search. || NOTE: While strchr(s, 0); may be used to find the end of the || string this is slow compared to using the construction: char *ptr || = s + strlen(s); /* ptr = end of string s */. INPUTS char *s; pointer to the string to search int c; character to search for. RESULTS char *ptr; pointer to the first occurrence of character c in s or NULL if c could not be found in s. SEE ALSO strrchr EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { char *s = "We feel incredibly agile"; char *ptr; ptr = strchr(s, 'i'); assert(ptr == s + 2); puts(ptr); /* "incredibly agile" */ return(0); } dice/strcmp dice/strcmp FUNCTION compare two strings (ANSI) SYNTAX #include <string.h> int r = strcmp(s1, s2); const char *s1; const char *s2; DESCRIPTION strcmp compares two strings, returning -1 if s1 < s2, 0 if s1 == s2 , and 1 if s1 > s2. || NOTE: strcmp converts the chars in the string to unsigned || quantities when comparing them. However, for portability you || should not strcmp strings containing negative characters (bit 7 || set) for anything other than checking the result against 0. Use || the memcmp routine instead. INPUTS char *s1; pointer to first string char *s2; pointer to second string RESULTS int r; -1, 0, or 1. SEE ALSO strncmp, stricmp EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { char *s1 = "abca"; char *s2 = "abcd"; char *s3 = "abcx"; char *s4 = "abcdx"; char *s5 = "abc"; char *x2 = "abcd"; int r; r = strcmp(s2, x2); /* string s2 same as string x2 */ assert(r == 0); r = strcmp(s2, s1); /* string s2 larger than string s1*/ assert(r > 0); r = strcmp(s2, s3); assert(r < 0); r = strcmp(s2, s4); assert(r < 0); r = strcmp(s2, s5); assert(r > 0); return(0); } dice/strcpy dice/strcpy FUNCTION copy a string returning a pointer to the beginning of the destination (ANSI) SYNTAX #include <string.h> char *ptr = strcpy(d, s); char *d; char *s; DESCRIPTION strcpy copies the NULL terminated string pointed to by s to the buffer d. The NULL is copied. The first argument is returned (a pointer to the buffer d). INPUTS char *d; pointer to beginning of destination buffer char *s; pointer to beginning of source string RESULTS char *ptr; same as the destination buffer pointer (d). SEE ALSO stpcpy EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> /* * Note that the stpcpy() example accomplishes the same * thing and is more efficient, but also requires the * use of a temporary pointer as well as cluttering the * source and being non-standard. * strcpy()/strcat() is more portable, though less * efficient. */ main() { char *buf1 = "saber"; char *buf2 = "tooth"; char dest[32]; strcpy(dest, buf1); strcat(dest, buf2); puts(dest); /* sabertooth */ return(0); } dice/strcspn dice/strcspn FUNCTION scan a string until a character is found that matches any character in a second string (ANSI) SYNTAX #include <string.h> int len = strcspn(s, toks) const char *s; const char *toks; DESCRIPTION With strcspn, the string s is scanned until a character is found that matches any character in the string toks. The number of characters skipped is returned. If no character in s matches any character in toks then the length of the string s is returned. strcspn is normally used to search for whitespace within a string. Note that in many cases strpbrk is more useful than strcspn. INPUTS char *s; pointer to string to scan char *toks; pointer to string containing characters to compare against RESULTS int len; # of characters skipped in s before a match was found. SEE ALSO strpbrk, strspn EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { int len; len = strcspn("hello this is a test", " \tabcd"); assert(len == 5); /* stopped at the first space */ len = strcspn("hello this is a test", " abl"); assert(len == 2); /* stopped at the first 'l' */ len = strcspn("hello", "abcd"); assert(len == 5); /* stopped at end of string 1 */ return(0); } dice/strdup dice/strdup FUNCTION duplicate a string using malloc (DICE) SYNTAX #include <string.h> char *s2 = strdup(s1); const char *s1; DESCRIPTION strdup allocates enough space to hold s1 including the terminating NULL and then copies s1 into this space, returning a pointer to the new string. NULL is returned if space could not be allocated due to low memory conditions. Note free may be used to free the returned string. The amount allocated is (strlen(s1) + 1). || NOTE: This is a non-standard function and may not exist in other C || environments. INPUTS char *s1; pointer to the string to duplicate RESULTS char *s2; pointer to malloc'd space containing a duplicate of the string s1 or NULL if space could not be malloc'd. SEE ALSO malloc, free, strcpy, strlen EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> /* * Modifying string constants (quoted strings) may * not be entirely portable. Normally one does not * use strdup() to accomplish the following function * but instead declares a char array statically * initialized with the string, such as: * char FuBar[] = { "This is a test" }; * Which can be modified in a portable fashion without * having to duplicate the string. */ main() { char *s1 = "this is a test"; char *s2; s2 = strdup(s1); s2[0] = 'x'; puts(s2); /* this is a test */ free(s2); s2 = strdup(s1); s2[1] = '0'; puts(s2); /* this is a test */ free(s2); return(0); } dice/strerror dice/strerror FUNCTION return error string associated with error code (ANSI) SYNTAX #include <string.h> const char *str = strerror(error); int error; DESCRIPTION strerror returns a read-only string associated with the specified error, usually taken from errno after some c.lib call fails. An unknown error will result in the string "unknown error." INPUTS int error; error code RESULTS char *str; error string SEE ALSO perror EXAMPLE #include <stdio.h> #include <string.h> #include <errno.h> #include <assert.h> main() { FILE *fi; fi = fopen("ThisFileDoesNotExist", "r"); assert(fi == NULL); puts(strerror(errno)); return(0); } dice/strftime dice/strftime FUNCTION convert broken down time into a string according to a format (ANSI) SYNTAX #include <time.h> size_t len = strftime(buf, max, fmt, tm) char *buf; size_t max; const char *fmt; const struct tm *tm; DESCRIPTION strftime formats a broken down time into a buffer according to a format string fmt. The fmt string looks like a the format for a printf except with different control definitions: %% A literal '%' character. %a The locale's abbreviated name for the day of week. %A The locale's full name for the day of week. %b The locale's abbr. name for the month. %B The locale's full name for the month. %c The locale's default representation for the date & time (ctime). %d The day of the month 01-31. %H The hour 00-23 (24 hour time). %I The hour 01-12 (12 hour time). %j The day in the year 001-366. %m The month 01-12. %M The minute 00-59. %p Indication of morning or afternoon. In the US: "AM" or "PM". %S The second 00-59. %U The week of the year 00-53, Sunday is the first day in a week. %w The day of the week 0-6, Sunday=0 (standard). %W The day of the week 0-6, monday=0. %x The locale's default representation for the date only. %X The locale's default representation for the time only. %y The year mod 100 (00-99). %Y The full year (e.g. 1990). %Z The name of the locale's time zone, nothing if unknown. ## WARNING: There must be at least max + 1 bytes in buf or you ## might unexpectedly overwrite memory. INPUTS char *buf; buffer to write formatted string into size_t max; maximum size of buffer - 1 char *fmt; format string struct tm *tm; broken down time RESULTS size_t len; length of formatted string in buffer or 0 if the maximum was exceeded. SEE ALSO time, localtime, asctime, ctime, clock EXAMPLE #include <stdio.h> #include <time.h> main() { time_t t = time(NULL); struct tm *tp = localtime(&t); char buf[256]; strftime(buf, sizeof(buf) - 1, "Now is %A %d %B %Y %X", tp); puts(buf); return(0); } dice/stricmp dice/stricmp FUNCTION compare two strings, case insensitive (UNIX) SYNTAX #include <string.h> int r = stricmp(s1, s2); const char *s1; const char *s2; DESCRIPTION stricmp compares two strings, returning: -1 if s1 < s2, 0 if s1 == s2, or 1 if s1 > s2. differs from strcmp in that case is ignored for alphabetic characters, i.e. a == A. || NOTE: NOTE= stricmp converts the chars in the string to unsigned || quantities when comparing them. However, for portability you || should not stricmp strings containing negative characters (bit 7 || set) for anything other than checking the result against 0. Use || the memcmp routine instead. INPUTS char *s1; pointer to first string char *s2; pointer to second string RESULTS int r; -1, 0, or 1. SEE ALSO strcmp, strncmp EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { char *s1 = "abCa"; char *s2 = "aBcD"; char *s3 = "aBCX"; char *s4 = "ABCdx"; char *s5 = "Abc"; char *x2 = "ABCD"; int r; r = stricmp(s2, x2); /* string s2 same as x2 */ assert(r == 0); r = stricmp(s2, s1); /* string s2 larger than s1 */ assert(r > 0); r = stricmp(s2, s3); assert(r < 0); r = stricmp(s2, s4); assert(r < 0); r = stricmp(s2, s5); assert(r > 0); return(0); } dice/strins dice/strins FUNCTION insert one string within another (DICE) SYNTAX #include <string.h> void strins(d, s); char *d; const char *s; DESCRIPTION strins inserts string s into d by shifting the string in d over strlen(s) spaces and then copying s into the newly made hold (except for the NULL, of course). This result is s inserted into d. || NOTE: There must be enough room in d to insert s; if d is an array || of 32 chars and contains a string of 8 chars you can insert || another string of, say, 10 chars, but not of 30 chars. strins is || not an ANSI standard function. INPUTS char *d; destination to insert in front of char *s; source string to insert SEE ALSO strcpy, strcat, strlen EXAMPLE #include <stdio.h> #include <string.h> main() { char buf[32]; strcpy(buf, "This is a test"); strins(buf + 5, "<gak!> "); puts(buf); /* This <gak!> is a test */ return(0); } dice/strlen dice/strlen FUNCTION returns length of a string (ANSI) SYNTAX #include <string.h> int len = strlen(s); const char *s; DESCRIPTION When this function is used, the length of the requested string is returned. The string is scanned until a NULL terminator is found and the number of characters (not including the NULL) is returned. :: Beginner's Note: The length returned by strlen does not include :: the NULL. It is common error to forget this fact and reserve one :: too few bytes of storage! INPUTS char *s; string to obtain length of RESULTS int len; length of string SEE ALSO strcpy, strcat EXAMPLE #include <stdio.h> #include <string.h> main(int ac, char **av) { if( ac 1 ) { printf("%s is %d byte(s) long\n", av[1], strlen( av[1] ) ); } else printf("Gimme, gimme, gimme!!\n"); } dice/strncat dice/strncat FUNCTION concatenate a string to an existing string up to a maximum number of characters (ANSI) SYNTAX #include <string.h> char *d = strncat(d, s, n); char *d; const char *s; int n; DESCRIPTION strncat scans the destination buffer for the NULL terminator and then appends the source string to the destination buffer (removing the NULL terminator and placing one at the end after the concatenation). However, only up to n characters is concatenated including the NULL. If the source string is exactly n characters long no NULL will be appended. If the source string is longer than n characters then only the first n characters of the source string will be appended (and no NULL will be). A pointer to the beginning of the destination buffer is returned. INPUTS char *d; pointer to destination buffer which already contains a string (which could be just a \0). char *s; pointer to the NULL terminated source string int n; maximum number of characters to concatenate RESULTS char *d; same as the first argument, a pointer to the destination buffer. SEE ALSO strncpy, strcpy, strcat EXAMPLE #include <stdio.h> #include <string.h> main() { char d[32]; char *p; char *s1 = "grid"; char *s2 = "lock"; strcpy( d, s1 ); p = strncat( d, s2, 10 ); puts( d ); /* gridlock */ strcpy( d,I s1 ); p = strncat( d, s2, 3 ); puts( d ); /* gridloc */ return(0); } dice/strncmp dice/strncmp FUNCTION compare two strings up to a maximum number of characters (ANSI) SYNTAX #include <string.h> int r = strncmp(s1, s2, n); const char *s1; const char *s2; int n; DESCRIPTION strncmp compares two strings, returning: -1 if s1 < s2, 0 if s1 == s2, or 1 if s1 > s2. strncmp works like strcmp but only up to n characters will be compared. If all characters compare when n is reached 0 is returned indicating that the strings matched. Fewer characters might be compared if either string terminates (w/ a NULL) before the maximum is reached or a compare fails (scan is stopped and -1 or 1 is returned immediately). || NOTE: strncmp converts the chars in the string to unsigned || quantities when comparing them. However, for portability you || should not strncmp strings containing negative characters (bit 7 || set) for anything other than checking the result against 0. Use || the memcmp routine instead. INPUTS char *s1; pointer to first string char * s2; pointer to second string int n; maximum number of characters to compare RESULTS int r; -1, 0, or 1. SEE ALSO stricmp EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { char *s1 = "abcaq"; char *s2 = "abcdr"; char *s3 = "abcxs"; char *s4 = "abcdxx"; char *s5 = "abc"; char *x2 = "abcdt"; int r; r = strncmp(s2, x2, 4); assert(r == 0); r = strncmp(s2, s1, 4); assert(r > 0); r = strncmp(s2, s3, 4); assert(r < 0); r = strncmp(s2, s4, 8); assert(r < 0); r = strncmp(s2, s5, 4); assert(r > 0); return(0); } dice/strncpy dice/strncpy FUNCTION copy a string returning a pointer to the beginning of the destination until NULL or the specified number of characters is reached (ANSI) SYNTAX #include <string.h> char *ptr = strncpy(d, s, n); char *d; const char *s; int n; DESCRIPTION strncpy copies the NULL terminated string pointed to by s to the buffer d. The NULL is normally copied. The first argument is returned (a pointer to the buffer d). The copy will also be terminated if the specified maximum is reached, in which case the NULL is NOT copied (which makes the function useless - but hey, it does make it standard). INPUTS char *d; pointer to beginning of destination buffer char *s; pointer to beginning of source string int len; maximum number of characters to copy RESULTS char *ptr; same as the destination buffer pointer (d). SEE ALSO stpcpy, strcpy EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { char *buf1 = "hello"; char *buf2 = "123"; char dest[32]; strncpy(dest, buf1, 8); strcat(dest, buf2); puts(dest); /* hello123 */ dest[2] = 23; strncpy(dest, buf1, 2); assert(dest[2] == 23); /* copy just two */ dest[2] = 0; /* we have to add the NULL */ puts(dest); /* he */ strcat(dest, buf2); /* he123 */ puts(dest); return(0); } dice/strnicmp dice/strnicmp FUNCTION compare two strings up to a maximum number of characters, case insensitive (UNIX) SYNTAX #include <string.h> int r = strnicmp(s1, s2, n); const char *s1; const char *s2; int n; DESCRIPTION strnicmp compares two strings, returning: -1, s1 < s2; 0, s1 == s2; 1, s1 > s2. strnicmp differs from strcmp in that case is ignored for alphabetic characters (i.e., a == A) and only up to n characters are compared. Refer to stricmp and strncmp for other examples. || NOTE: strnicmp converts the chars in the string to unsigned || quantities when comparing them. However, for portability you || should not strnicmp strings containing negative characters (bit 7 || set) for anything other than checking the result against 0. Use || the memcmp routine instead. INPUTS char *s1; pointer to first string char *s2; pointer to second string int n; maximum # of characters to compare RESULTS int r; -1, 0, or 1. SEE ALSO strcmp, strncmp, stricmp EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { char *s1 = "aBcAQ"; char *s2 = "abCDR"; char *s3 = "ABcXs"; char *s4 = "aBCDxX"; char *s5 = "aBC"; char *x2 = "AbCDt"; int r; r = strnicmp(s2, x2, 4); assert(r == 0); r = strnicmp(s2, s1, 4); assert(r > 0); r = strnicmp(s2, s3, 4); assert(r < 0); r = strnicmp(s2, s4, 8); assert(r < 0); r = strnicmp(s2, s5, 4); assert(r > 0); return(0); } dice/strpbrk dice/strpbrk FUNCTION search for specific characters in a string (ANSI) SYNTAX #include <string.h> char *ptr = strpbrk(s, toks) const char *s; char *toks; DESCRIPTION strpbrk searches the string s for any character in the string toks. For example, when searching for whitespace in s, toks would contain the space and tab character. If no character in s matches any character in toks then NULL is returned. INPUTS char *s; pointer to string to scan char *toks; pointer to string containing tokens to scan for RESULTS char *ptr; pointer to point in s where the character matches any character in toks, or NULL if s was exhausted. SEE ALSO strtok EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { char *s = "This \tis a test"; char *ptr; ptr = strpbrk(s, " \t"); assert(ptr == s + 4); ptr = strpbrk(ptr + 1, " \t"); assert(ptr == s + 5); ptr = strpbrk(ptr + 1, " \t"); assert(ptr == s + 6); ptr = strpbrk(ptr + 1, " \t"); assert(ptr == s + 9); ptr = strpbrk(ptr + 1, "xyz"); /* doesn't find 'm */ assert(ptr == NULL); return(0); } dice/strrchr dice/strrchr FUNCTION search for a character in a string, scan backwards (ANSI) SYNTAX #include <string.h> char *ptr = strrchr(s, c) const char *s; int c; DESCRIPTION strrchr searches for the character c within the string pointed to by s. The terminating NULL at the end of s is included in the search. The string is searched backwards. A pointer to the last occurrence of c in s is returned or NULL if c could not be found. C is converted to an 8 bit quantity by strrchr. || NOTE: The ANSI spec does not say anything about including the NULL || character in the search for strrchr and some implementation may || thus not implement this properly. INPUTS char *s; pointer to the string to search int c; character to search for RESULTS char *ptr; pointer to the last occurrence of character c in s or NULL if c could not be found in s. SEE ALSO strchr EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { char *s = "this is a test"; char *ptr; ptr = strrchr(s, 'i'); assert(ptr == s + 5); puts(ptr); /* "is a test" */ ptr = strrchr(s, 'x'); assert(ptr == NULL); return(0); } dice/strspn dice/strspn FUNCTION scan a string until a character is found that does not match some character in a second string (ANSI) SYNTAX #include <string.h> int len = strspn(s, toks) const char *s; const char *toks; DESCRIPTION The string s is scanned until a character is found that does not match any character in the string toks. The number of characters skipped is returned. If every character in s matches some character in toks then the length of the string s is returned. strspn is normally used to skip whitespace within a string. INPUTS char *s; pointer to string to scan char *toks; pointer to string containing characters to compare against RESULTS int len; # of characters skipped in s before a match could not be found SEE ALSO strpbrk, strcspn EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { int len; len = strspn(" \t \t\t abcde test", " \t "); assert(len == 7); /* stopped at the 'a' */ len = strspn("abcd efg", " "); assert(len == 0); /* stopped at the 'a' */ len = strspn(" \t\t ", " \t"); assert(len == 6); /* all match, len=strlen(str); */ return(0); } dice/strstr dice/strstr FUNCTION find sub-string within another string (ANSI) SYNTAX #include <string.h> char *ptr = strstr(s, sub); const char *s; const char *sub; DESCRIPTION The string s is scanned until the sub-string sub matches the string beginning at the current scan point, and a pointer to the sub-string within s is returned. If the sub-string could not be found NULL is returned. INPUTS char *s; pointer to string to scan char *toks; pointer to string containing characters to compare against RESULTS char *ptr; point in s where sub string was found or NULL if sub string could not be found. SEE ALSO strpbrk, strcspn EXAMPLE #include <stdio.h> #include <string.h> #include <assert.h> main() { char *s = "abcdefghijklmnopqrstuvwxyz"; char *ptr; ptr = strstr(s, "klm"); assert(ptr == s + 10); puts(ptr); /* klmnopqrstuvwxyz */ return(0); } dice/strtod dice/strtod FUNCTION convert string to fp double (ANSI) LIBRARY m.lib SYNTAX #include <string.h> double d = strtod(s, &tp); const char *s; char *tp; DESCRIPTION strtod converts a string to a floating point double. Initial whitespace is skipped. The format of the fp number in the string is then: {+/-/<nothing>}ddddd[.ddddd][E{+/-/<nothing>}dddd] Example fp strings: " +1.234E-3", "-1234", "6.5676E4", "214.2345" INPUTS char *s; pointer to string containing fp number char **tp; pointer to pointer, the pointer is modified to point to the end of the scanned fp number. RESULTS double d; resulting double EXAMPLE /* * compile -lm to include math library */ #include <stdio.h> #include <string.h> main() { double d; char *tp; d = strtod("1.2134 3.45E2", &tp); printf("1.2134 = %lf\n", d); /* 1.213400 */ d = strtod(tp, &tp); printf("3.45E2 = %lf\n", d); /* 345.000000 */ return(0); } dice/strtok dice/strtok FUNCTION break up a string into arguments (ANSI) SYNTAX #include <string.h> char *arg = strtok(s, toks) char *s; const char *toks; DESCRIPTION strtok breaks up a string into arguments. It determines the break point from the toks string which contains a set of whitespace characters (usually \t to mean space and tab). The first call to strtok should specify the string s and toks. Initial whitespace is skipped and the string is then scanned until the end of the first argument is found. The string is then modified: a NULL is placed at the end of the first argument and a pointer to the beginning of the first argument is returned. Further calls to strtok should pass a NULL for the string s, which tells strtok to continue scanning the original string (whose pointer was stored in a static char * within strtok). strtok returns arguments until the string is exhausted, in which case it returns NULL. The initial call to strtok can return NULL if the passed string s contains nothing but whitespace (as specified by toks). You can change the toks string at any time (i.e. pass a different toks string to strtok). ## WARNING: strtok modifies the source string and returns pointers ## into it. INPUTS char *s; pointer to string to parse char *toks; pointer to string containing whitespace characters (argument delimiters) RESULTS char *arg; pointer into s to next argument that is NULL terminated (s is modified). SEE ALSO strspn, strcspn EXAMPLE #include <stdio.h> #include <string.h> main() { char buf[32]; char *arg; const char *ws = " \t"; /* * 'This' 'is' 'a' 'test!' */ strcpy(buf, " This is \t \t a test!"); for (arg = strtok(buf, ws); arg; arg = strtok(NULL, ws)) { printf("arg = '%s'\n", arg); } return(0); } dice/strtol,strtoul dice/strtol,strtoul FUNCTION convert string to integer (ANSI) SYNTAX #include <string.h> long v = strtol(str, &tail, base); unsigned long v = strtoul(str, &tail, base); const char *str; char *tail; int base; DESCRIPTION strtol converts a string into an integer using the specified base 0-36. If a non-zero base is specified conversion is done using that base (hex numbers may still be preceded by '0x' or '0X'). If 0 is specified for the base then the base is determined from the first one or two characters of the number portion of the string: 0 octal 1-9 decimal 0x hex (0x or 0X) For bases larger than 10, alphabetic characters are used to represent digits. Either lower case or upper case letters may be used. strtol stores a pointer to the remainder of the string after the conversion. strtol ignores any whitespace at the beginning of the string and also handles an optional negative sign (which may precede the numerical portion of the string). If successful strtol returns the converted value as a long, 0 if it was unable to convert anything, and an undefined result if the converted value was out of range. || NOTE: strtol supersedes atoi and atol. INPUTS char *str; pointer to string to convert char **tail; *tail modified to point to just after last character converted int base; base of conversion or 0 for autoselect RESULTS long v; converted result, an integer, or 0 if no conversion could be done. SEE ALSO atoi, atol, strtod EXAMPLE #include <stdio.h> #include <string.h> main(int ac, char**av) { long v; char *tail; if (ac != 3) { puts("testprg <string> <base>"); puts("testprg 0123abc 0"); puts("testprg 0x1000 0"); puts("testprg 0123abc 16"); exit(1); } v = strtol(av[1], &tail, atoi(av[2])); printf("v = %d, tail = %s\n", v, tail); return(0); } dice/system dice/system FUNCTION call system shell with a command line (ANSI) SYNTAX #include <stdio.h> #include <stdlib.h> int r = system(buf); const char *buf; DESCRIPTION system calls the system shell with the specified command line, returning the exit code of the command or -1 if it was unable to run the command. || NOTE: FOR PROGRAMS COMPILED UNDER 1.3, even if run in 2.0 || environment, the system call will not return the exit code from || the command, but return -1 if could not be run, 0 if it could. || NOTE: FOR PROGRAMS COMPILED UNDER 2.0, system will use the 2.0 || calls and return a proper exit code when running under 2.0, and || will use execute if running under 1.3. INPUTS char *buf; command line to run, like a normal AmigaDOS CLI command line. RESULTS int r; return code EXAMPLE main() { int r; r = system("c:type s:startup-sequence"); printf("System returns %d\n", r); } dice/tan,ftan dice/tan,ftan FUNCTION tan: return tan of a double quantity (ANSI) ftan: return tan of a float quantity (ANSI) LIBRARY m.lib SYNTAX #include <math.h> double a = tan(b); double b; float c = ftan(d); float d; DESCRIPTION tan returns the tangent of a double quantity; ftan returns the tangent of a floating point quantity. INPUTS double b; double floating point value float d; float floating point value RESULTS double a; double floating point value float c; float floating point value SEE ALSO acos, asin, atan, cos, exp, fabs, log, log10, pow, sin, sqrt, tan, facos, fasin EXAMPLE /* * compile with the math library -lm */ #include <math.h> #include <stdio.h> main() { { double a = tan(0.25); printf("tan 0.25 = %lf\n", a); /* 0.2553 */ } { /* less accuracy */ float a = ftan(0.25); printf("tan 0.25 = %lf\n", (double)a); } return(0); } dice/time dice/time FUNCTION get current time (ANSI) SYNTAX #include <time.h> time_t t = time(NULL); or time(&t); time_t t; DESCRIPTION time returns the current time as a time_t and also copies it into a time_t if the address of said is passed as an argument. You may pass NULL as an argument in which case the time is only returned. The time is returned as seconds since some base date, time_t is normally an unsigned long. INPUTS time_t *t; pointer to a time_t or NULL RESULTS time_t t; a time_t SEE ALSO time, localtime, asctime, strftime, ctime, clock EXAMPLE #include <stdio.h> #include <time.h> main() { time_t t = time(NULL); printf("t = %u\n", t); return(0); } dice/tmpfile dice/tmpfile FUNCTION create a temporary file (ANSI) SYNTAX #include <stdio.h> FILE *fp = tmpfile(void); DESCRIPTION tmpfile creates a temporary file and returns a file pointer. The name of the file is not accessible. The file pointer is available or reading, writing, and seeking (as in rewind, fseek). The file is initially empty. This call may be used to create a temporary file that will automatically be removed when you fclose it. tmpfile returns a FILE pointer or NULL if it was unable to create the file. INPUTS none RESULTS FILE *fp; opened temporary file SEE ALSO tmpnam, fopen, fclose EXAMPLE #include <stdio.h> #include <assert.h> main() { FILE *fp = tmpfile(); char buf[256]; assert(fp); fputs("This is a test of\n" "a temporary file\n" "fubar bletch\n", fp); rewind(fp); while (fgets(buf, sizeof(buf), fp)) { fputs(buf, stdout); } fclose(fp); /* close and delete the file */ return(0); } dice/tmpnam dice/tmpnam FUNCTION create a unique, temporary file name (ANSI) SYNTAX #include <stdio.h> char *filename = tmpnam(buf); char *buf; DESCRIPTION tmpnam creates a unique temporary file name meant never to be seen by the user. The filename tmpnam creates will be no more than L_tmpnam bytes long (L_tmpnam is a macro in <stdio.h>), including the NULL so you can simply declare a buffer: char buf[L_tmpnam];. tmpnam returns the buffer into which it created the temporary file name. If you specify a non-NULL buffer it returns its first argument. If you pass NULL to tmpnam then tmpnam will use its down internal static buffer (overwriting any previous name that was stored in said buffer) and return a pointer to that. INPUTS char *buf; optional buffer of at least L_tmpnam bytes to hold the temporary file name or NULL to have tmpnam() use its own internal buffer. RESULTS char *ptr; pointer to buffer (buf if buf != NULL) SEE ALSO tmpfile EXAMPLE #include <stdio.h> #include <assert.h> main() { char buf[L_tmpnam]; char *ptr; ptr = tmpnam(NULL); puts(ptr); assert(tmpnam(buf) == buf); /* returns argument */ puts(buf); /* haven't overwritten it yet */ printf("%s (same as first)\n", ptr); assert(tmpnam(NULL) == ptr); /* that will overwrite it! */ puts(ptr); return(0); } dice/tolower,toupper dice/tolower,toupper FUNCTION convert a character into lower or upper case (ANSI) SYNTAX #include <ctype.h> int lc = tolower(c); int uc = toupper(c); int c; || NOTE: These are MACROS if you #include <ctype.h>, subroutine calls || if you do not. DESCRIPTION toupper converts a character from lower to upper case, while tolower does the reverse. Characters that are not of type upper or lower case (see isupper and islower) are left unchanged. || NOTE: Characters in the -1 to 255 range are valid inputs. || Characters less than -1 or larger than 255 are illegal and the || results will be random. If you are passing a CHAR, you must cast || it to an UNSIGNED CHAR first. EOF is a valid input an always || returns false (zero). INPUTS int c; character to be converted RESULTS int lc, uc; converted character SEE ALSO isalnum, isalpha, iscntrl, isdigit, isgraph, islower, isprint, ispunct, isspace, isupper, isxdigit EXAMPLE #include <stdio.h> #include <ctype.h> main() { int c; /* Print all 256 characters, showing conversions */ for( c=0; c<256; c++) { if( (c & 31) == 0 ) /* 32 per line */ printf("\n%02x: ", c); if( isprint( c ) ) /* if printable ... */ printf("%c", tolower( c ) ); else printf("%c", 127); /* if not-printable */ } printf("\n"); return( 0 ); } dice/ungetc dice/ungetc FUNCTION push a character back onto a file pointer's input stream (ANSI) SYNTAX #include <stdio.h> int r = ungetc(c, fp); int c; FILE *fp; DESCRIPTION ungetc pushes the specified character back onto the input stream, as if it had not been read. Only ONE character may be pushed back onto an input stream at a time. If all went well, the return value r is equal to c. Else EOF is returned if too many characters were pushed back. Some implementations of C allow multiple characters to be pushed back. The majority, including DICE, allows only one. ungetc is useful when, in scanning an input stream, you overshoot the 'last' character you wanted a particular routine to retrieve. This routine can push the character back onto the input stream with ungetc so another routine's getc (getchar, fread, fgetc, etc...) will get that character back. INPUTS int c; character to push back onto input stream FILE *fp; file pointer stream to push character on to. RESULTS int r; pushed character (c) if no error, EOF if error SEE ALSO getc, getchar, fread, fgetc EXAMPLE #include <stdio.h> #include <ctype.h> main() { void scan_number(); void scan_alpha(); puts("Enter nnnaaannn where n=digit a=alpha"); puts("Example: 1234abcd99"); printf("? "); fflush(stdout); scan_number(); puts("--"); scan_alpha(); puts("--"); scan_number(); return(0); } static void scan_number() { short c; for (c = getchar(); c >= '0' && c <= '9'; c = getchar()) { printf("digit: %c\n", c); } if (c != EOF) ungetc(c, stdin); } static void scan_alpha() { short c; for (c = getchar(); tolower(c) >= 'a' && tolower(c) <= 'z'; c =getchar()) { printf("alpha: %c\n", c); } if (c != EOF) ungetc(c, stdin); } dice/unlink dice/unlink FUNCTION delete a file (UNIX) SYNTAX #include <stdio.h> int r = unlink(filename); char *filename; DESCRIPTION unlink deletes a file, equivalent to remove. This call deletes a file from the filesystem. unlink exists for UNIX compatibility only. Use rmdir to delete a directory if you wish to maintain portability. INPUTS char *filename; name of file to delete RESULTS int r; 0 if successful, non-zero if error SEE ALSO close, creat, fcntl, fdtofh, ioctl, isatty, lseek, mkdir, open, read, rmdir, unlink, write EXAMPLE main() { int r; r = unlink("T:xx"); if (r == 0) puts("Deleted T:xx"); else puts("Unable to delete t:xx or it does not exist"); return(0); } dice/wbmain dice/wbmain FUNCTION main program entry when run from Workbench (DICE) SYNTAX #include <startup.h> int wbmain(struct WBStartup *wbs) { /* your main code goes here */ return(exitcode); } DESCRIPTION The wbmain routine is the entry point called after normal initialization of c.lib and the program environment is done by the startup module (c.o) and _main() routine (in c.lib). wbmain is called when the program is run from the workbench, main is called when the program is run from the CLI. The exit code is ignored. The standard workbench startup message is passed to wbmain, you can process or ignore this message as you like but should NOT ReplyMsg it. We repeat, do not ReplyMsg it. When you return from wbmain or exit out of the program the exit code will automatically deal with the message. SEE ALSO main EXAMPLE /* * If run from the workbench this program will create a * file T:XX instead of printing something on the * console (since there is no console in that case). */ #include <stdio.h> int main(int ac, char**av) { puts("This was run from a CLI"); return(0); } int wbmain(msg) void *msg; /* cheat to make the example less complex */ { FILE *fi = fopen("T:xx", "w"); fprintf(fi, "This was run from the WORKBENCH\n"); fclose(fi); } dice/write dice/write FUNCTION write data to a file (UNIX) SYNTAX #include <fcntl.h> int r = write(fd, buf, bytes); int fd; void *buf; int bytes; DESCRIPTION write writes data to a file, starting at the current seek position. It extends the file if necessary, or else writes over existing data. With normal files, write will always return the number of bytes requested and fewer only if an error occurs. With devices write may or may not return the number of bytes requested depending on the device, though usually it does. || NOTE: Refer to the file_descriptor manual page for general || information. Unlike file pointers and file handles, the file || descriptor is checked for validity and will simply return an error || if illegal. INPUTS int fd; file descriptor to write to void *buf; pointer to buffer to write data from int len; number of bytes to write RESULTS int r; number of bytes actually written, usually an error if r !=len. SEE ALSO close, creat, fcntl, fdtofh, ioctl, isatty, lseek, mkdir, open, read, rmdir, unlink EXAMPLE See open for an example dice/x.o dice/x.o FUNCTION autoinit terminating tags (DICE) LIBRARY x.o DESCRIPTION The X.O module is the normally the last object module specified when linking. DICE has a very unique and elegant system of creating automatic initialization and exit code. The X.O module terminates these special sections. Autoinit/exit sections work as follows: any object module may define a specially named section which will be linked, in sequence, with other module's sections of the same name. These sections contain only code and no RTS. The terminating module X.O adds a single RTS to each section, allowing the base of the section to be called by the startup/exit module (C.O). Execution propagates through all autoinit/exit routines before hitting the RTS placed in the section by X.O. DICE uses autoinit/exit sections to handle the following things: 1) Code to initialize initialized data containing references to other initialized data (i.e. int a, *b = &a;) when the code must be made residentable. This precludes the need for the startup code to handle Data-Data 32-bit relocations for resident code. 2) Code to open libraries whos base variables are referenced but never declared. _DOSBase and the various floating point libraries are automatically opened in this way whenever library calls to them are made. This precludes the need for DICE to have massive, complex, and many times unnecessary code in c.lib to handle these situations. 3) Code to close libraries that were opened by (2) on exit. 4) Entry points for the special __autoinit keyword. SEE ALSO c.o EXAMPLE dlink dlib:c.o myprog.o dlib:x.o -o myprog -v