@DataBase "ANSI-C Keywords" @Author LouiSe @Node Main "ANSI-C Keywords" ANSI-C Keywords for searching by LouiSe '97 @EndNode @Node "rand()" rand()-Generate a random number Synopsis #include x = rand(void); int x; /* random number */ Portability Returns This function returns an integer value as noted above. See Also @{" drand48() " Link "drand48()"} , @{" srand() " Link "srand()"} @EndNode @Node "realloc()" realloc()-reallocate level 3 memory Synopsis #include nb = realloc(b,n); void *b; /* block pointer */ size_t n; /* number of bytes */ void *nb; /* new block pointer */ Portability Returns This function returns a null pointer if there is not enough space for the requested block. In this case, the original block b is unchanged. See Also @{" calloc() " Link "calloc()"} , @{" free() " Link "free()"} , @{" getmem() " Link "getmem()"} , @{" malloc() " Link "malloc()"} , @{" rlsmem() " Link "rlsmem()"} , @{" sbrk() " Link "sbrk()"} , @{" rbrk() " Link "rbrk()"} @EndNode @Node "remove()" remove()-remove a file Synopsis #include error = remove(name); int error; /* non-zero if error */ const char *name; /* file name */ Portability Returns If a non-zero value is returned, some type of error occurred, and additional information can be found in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. The most common errors occur when you try to remove a file that doesn't exist, that is marked as read-only, or is in use. See Also @{" errno " Link "errno"} , @{" _OSERR " Link "_OSERR"} , @{" unlink() " Link "unlink()"} @EndNode @Node "rename()" rename()-rename a file Synopsis #include error = rename(old,new); int error; /* 0 for success, nonzero for error */ const char *old; /* old file name */ const char *new; /* new file name */ Portability Returns If the function fails, it returns a nonzero integer and places additional error information into @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. If it is successful, it returns a 0. @EndNode @Node "rewind()" rewind()-Reset level 2 file position to first byte Synopsis #include void rewind(fp); FILE *fp; /* file pointer */ Portability See Also @{" errno " Link "errno"} , @{" fseek() " Link "fseek()"} , @{" fopen() " Link "fopen()"} , @{" _OSERR " Link "_OSERR"} , @{" lseek() " Link "lseek()"} , @{" tell() " Link "tell()"} @EndNode @Node "scanf()" scanf()-Formatted input conversions Synopsis #include n = scanf(fmt,arg1,arg2,...); int n; /* number of input items matched, or EOF */ const char *fmt; /* format string */ ---- *arg ; /* pointers to input data areas */ Portability Returns The function returns the number of assignments that were made. For example, a return value of three indicates that conversion results were assigned to arg1, arg2, and arg3. See Also @{" fscanf() " Link "fscanf()"} , @{" sscanf() " Link "sscanf()"} , @{" Formatted Input Specifiers " Link "Formatted Input Specifiers"} @EndNode @Node "modf()" modf()-Split floating point value Synopsis #include x = modf(y,p); double x; /* fractional part of y */ double y; /* number to be broken up */ double *p; /* integral part of y */ Portability Returns The function return value is the fractional part of y, and the integral part is placed in the double pointed to by p. See Also @{" fmod() " Link "fmod()"} @EndNode @Node "offsetof()" offsetof()-Get the byte offset of a structure member Synopsis #include size_t offsetof(type, element) Portability Returns This macro returns the byte offset of element, within the structure type. @EndNode @Node "onexit()" onexit()-Set an exit trap Synopsis #include success = onexit(func); int success; /* non-zero for success */ void (*func)(void); /* trap function pointer */ Portability Returns A zero is returned for success and a non-zero value is returned if an error is encountered. See Also @{" exit() " Link "exit()"} @EndNode @Node "perror()" perror()-Print error message Synopsis #include void perror(s); const char *s; /* message prefix */ Portability See Also @{" errno " Link "errno"} , @{" poserr() " Link "poserr()"} , @{" __sys_errlist " Link "__sys_errlist"} , @{" __sys_nerr " Link "__sys_nerr"} @EndNode @Node "pow()" pow()-raise a number to a power Synopsis #include r = pow(x,y); double r, x, y; Portability See Also @{" __matherr() " Link "__matherr()"} , @{" pow2() " Link "pow2()"} @EndNode @Node "printf()" printf()-Formatted print to stdout Synopsis #include length = printf(fmt,arg1,arg2,...); int length; /* number of characters generated */ const char *fmt; /* format string */ .... arg ; /* arguments */ Portability Returns This function returns the number of output characters generated. See Also @{" fprintf() " Link "fprintf()"} , @{" sprintf() " Link "sprintf()"} , @{" Formatted Output Specifiers " Link "Formatted Output Specifiers"} @EndNode @Node "putc()" putc()-Put a character to a level 2 file Synopsis #include r = putc(c,fp); int r; /* EOF or c */ int c; /* Character to be output */ FILE *fp; /* Level 2 file pointer */ Portability Returns If successful, this function returns the character to be output; otherwise, it returns EOF. For disk files, an EOF return usually means that the disk is full. However, this type of return can also occur if the device is write-protected or if a write error occurs. In any case, additional error information can be found in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. See Also @{" errno " Link "errno"} , @{" fopen() " Link "fopen()"} , @{" _OSERR " Link "_OSERR"} @EndNode @Node "putchar()" putchar()-Put a character to stdout Synopsis #include r = putchar(c); int r; /* EOF or c */ int c; /* Character to be output */ Portability Returns If successful, this function returns the character that was output; otherwise, it returns EOF. For disk files, an EOF return usually means that the disk is full. However, this type of return can also occur if the device is write-protected or if a write error occurs. In any case, additional error information can be found in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. See Also @{" errno " Link "errno"} , @{" fopen() " Link "fopen()"} , @{" _OSERR " Link "_OSERR"} @EndNode @Node "puts()" puts()-Put string to stdout Synopsis #include error = puts(s); int error; /*non-zero if error*/ const char *s; /*string pointer*/ Portability Returns If an error occurs, the return value is -1; otherwise, it is 0. Additional error information can be found in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. See Also @{" errno " Link "errno"}, @{" ferror() " Link "ferror()"} , @{" fopen() " Link "fopen()"} , @{" fputc() " Link "fputc()"} , @{" fputs() " Link "fputs()"} , @{" _OSERR " Link "_OSERR"} @EndNode @Node "qsort()" qsort()-Sort a data array Synopsis #include void qsort(a,n,size,cmp); void *a; /* data array pointer */ size_t n; /* number of elements in array */ size_t size; /* element size in bytes */ /* pointer to comparison function */ int (*cmp)(const void *, const void *); Portability See Also @{" dqsort() " Link "dqsort()"} , @{" fqsort() " Link "fqsort()"} , @{" lqsort() " Link "lqsort()"} , @{" sqsort() " Link "sqsort()"} , @{" tqsort() " Link "tqsort()"} @EndNode @Node "raise()" raise()-Generate a signal Synopsis #include ret = raise(sig); int ret; /* 0 if successful, nonzero if failed */ int sig; /* signal() to generate */ Portability Returns A non-zero return value indicates failure. See Also @{" signal() " Link "signal()"} , @{" __matherr() " Link "__matherr()"} , @{" onbreak() " Link "onbreak()"} , @{" _CXBRK() " Link "_CXBRK()"} , @{" _CXFERR() " Link "_CXFERR()"} @EndNode @Node "main()" main()-Your main or principal function Synopsis #include "workbench/startup.h" void main(argc,argv); int argc; /* argument count */ union { char *args[]; struct WBStartup *msg; } argv; /* argument vector */ Portability Returns When main() returns to its caller (normally _main.c), the program exits to AmigaDOS with a termination code of 0. If you want to pass a non-zero termination code back to AmigaDOS, use the @{" exit() " Link "exit()"} or @{" __exit() " Link "__exit()"} function. See Also @{" exit() " Link "exit()"} , @{" __exit() " Link "__exit()"} , @{" __main() " Link "__main()"} @{" __tinymain() " Link "__tinymain()"} @EndNode @Node "malloc()" malloc()-Allocate memory Synopsis #include b = malloc(n); void *b; /*block pointer */ size_t n; /*number of bytes */ Portability Returns A null pointer is returned if there is not enough space for the requested block. See Also @{" calloc() " Link "calloc()"} , @{" free() " Link "free()"} , @{" getmem() " Link "getmem()"} , @{" rbrk() " Link "rbrk()"} , @{" realloc() " Link "realloc()"} , @{" rlsmem() " Link "rlsmem()"} , @{" sbrk() " Link "sbrk()"} @EndNode @Node "mblen()" mblen()-Determine length of multibyte character Synopsis #include length = mblen(s, n); int length; /* length or state information */ const char *s; /* pointer to characters or NULL */ size_t n; /* maximum number of characters to look at */ Portability Returns This function returns the amount of storage needed to hold result string. See Also @{" mbstowcs() " Link "mbstowcs()"} , @{" mbtowc() " Link "mbtowc()"} @EndNode @Node "mbstowcs()" mbstowcs()-Convert multibyte string to wide character string Synopsis #include length = mbstowcs(pwcs, s, n); size_t length; /* length or state information */ wchar_t *pwcs; /* pointer to wide character string */ const char *s; /* pointer to characters or NULL */ size_t n; /* maximum number of characters to look at */ Portability Returns This function returns the length of the result string. See Also @{" mblen() " Link "mblen()"} , @{" mbtowc() " Link "mbtowc()"} @EndNode @Node "mbtowc()" mbtowc()-Maps a multibyte character to a wide character Synopsis #include length = mbtowc(pwc, s, n); int length; /* length or state information */ wchar_t *pwc; /* pointer to wide character */ const char *s; /* pointer to characters or NULL */ size_t n; /* maximum number of characters to look at */ Portability Returns This function returns the length of the multibyte character defined by the locale information. If s is NULL or if n is equal to zero, this function returns a zero. See Also @{" mblen() " Link "mblen()"} , @{" mbtowc() " Link "mbtowc()"} @EndNode @Node "memchr()" memchr()-Find a character in a memory block Synopsis #include s = memchr(a,c,n); void *s; /* pointer to character in block */ const void *a; /* block pointers */ int c; /* character value */ size_t n; /* number of bytes */ Portability Returns This function returns a pointer to the first occurrence of the specified character in the block, or a null pointer if the character is not found. @EndNode @Node "memcmp()" memcmp()-Compare two memory blocks Synopsis #include x = memcmp(a,b,n); int x; /* return value */ const void *a,*b; /* block pointers */ size_t n; /* number of bytes */ Portability Returns This function returns an integral value as follows: Return Meaning ------ ------- Negative First block sorts below second Zero First block equals second Positive First block sorts above second @EndNode @Node "memcpy()" memcpy()-Copy a memory block Synopsis #include s = memcpy(to,from,n); void *s; /* return pointer */ void *to; /* destination pointer */ const void *from; /* source pointer */ size_t n; /* number of bytes */ Portability Returns This function returns a pointer to the destination block. See Also @{" memccpy() " Link "memccpy()"} , @{" memmove() " Link "memmove()"} , @{" movmem() " Link "movmem()"} , @{" strcpy() " Link "strcpy()"} @EndNode @Node "memmove()" memmove()-Copy bytes in memory Synopsis #include p = memmove(dest, source, nbytes); void *p; /* same as dest */ void *dest; /* destination for moved bytes */ const void *source; /* source of bytes for move */ size_t nbytes; /* number of bytes to be transferred */ Portability Returns This function returns a pointer to the destination block. See Also @{" memcpy() " Link "memcpy()"} , @{" movmem() " Link "movmem()"} , @{" strcpy() " Link "strcpy()"} @EndNode @Node "memset()" memset()-Set a memory block to a value Synopsis #include s = memset(to,c,n); void *s; /* return pointer */ void *to; /* destination pointer */ size_t n; /* number of bytes */ int c; /* character value */ Portability Returns This function returns a pointer to the destination block. See Also @{" setmem() " Link "setmem()"} @EndNode @Node "mktime()" mktime()-Convert broken down time to time_t value Synopsis #include t = mktime(ts); time_t t; /* number of seconds since 1/1/70 */ struct tm *ts; /* broken down time structure */ Portability Returns This function returns the number of seconds since January 1, 1970. See Also @{" time() " Link "time()"} @EndNode @Node "isupper()" isupper()-Test if upper case character Synopsis #include t = isupper(c); int t; /* 0 if false, non-zero if true */ int c: /* character to test */ Portability Returns This function returns a non-zero value if c is an upper case letter, and a zero if not. See Also @{" __ctype " Link "__ctype"} @EndNode @Node "isxdigit()" isxdigit()-Test if hex digit character Synopsis #include t = isxdigit(c); int t; /* 0 if false, non-zero if true */ int c: /* character to test */ Portability Returns This function returns a non-zero value if c is a valid hexidecimal digit (including both upper and lower case A-F), and a zero if not. See Also @{" __ctype " Link "__ctype"} @EndNode @Node "labs()" labs()-Long integer absolute value Synopsis #include al = labs(l); long int al,l; Portability Returns This function returns a long integer holding the absolute value of the parameter. See Also @{" abs() " Link "abs()"} , @{" fabs() " Link "fabs()"} , @{" iabs() " Link "iabs()"} @EndNode @Node "ldexp()" ldexp()-Combine float value Synopsis #include v = ldexp(d,x); double v; /* value */ double d; /* fraction */ int x; /* exponent */ Portability Returns This function returns a double holding the result of the above equation. See Also @{" fmod() " Link "fmod()"} , @{" frexp() " Link "frexp()"} , @{" __matherr() " Link "__matherr()"} , @{" modf() " Link "modf()"} @EndNode @Node "ldiv()" ldiv()-Return long quotient and remainder for divide Synopsis #include res = ldiv(numer, denom); ldiv_t res; /* resulting quotient and remainder */ long int numer; /* numerator for the divide */ long int denom; /* denominator for the divide */ Portability Returns This function returns a structure containing both the quotient and remainder. The structure is defined in stdlib.h as follows: typedef struct { long int quot; long int rem; } ldiv_t; See Also @{" div() " Link "div()"} @EndNode @Node "localeconv()" localeconv()-Return info on locale formatting conventions Synopsis #include lcl = localeconv(void); struct lconv *lcl; /* Locale information structure */ Portability Returns This function returns a pointer to the @{" lconv " Link "lconv"} structure for the current locale. See Also @{" setlocale() " Link "setlocale()"} @EndNode @Node "localtime()" localtime()-Unpack local time Synopsis #include ut = localtime(t); struct tm *ut; const time_t *t; Portability See Also @{" asctime() " Link "asctime()"} , @{" ctime() " Link "ctime()"} , @{" gmtime() " Link "gmtime()"} , @{" time() " Link "time()"} @EndNode @Node "log()" log()-Natural logarithm function Synopsis #include r = log(x); double r, x; Portability Returns This function returns a double that contains the base E logarithm of the parameter. See Also @{" log10() " Link "log10()"} , @{" __matherr() " Link "__matherr()"} @EndNode @Node "log10()" log10()-Base 10 logarithm function Synopsis #include r = log10(x); double r, x; Portability Returns This function returns a double the base 10 logarithm of the parameter. See Also @{" log() " Link "log()"} , @{" __matherr() " Link "__matherr()"} @EndNode @Node "longjmp()" longjmp()-Perform long jump Synopsis #include void longjmp(save,value); jmp_buf save; /* address of save area */ int value; /* return value */ Portability See Also @{" exit() " Link "exit()"} , @{" setjmp() " Link "setjmp()"} @EndNode @Node "gets()" gets()-Get string from stdin Synopsis #include p = gets(buffer); char *p; /*buffer pointer or NULL */ char *buffer; /*buffer pointer */ Portability Returns This function returns the buffer argument unless an I/O error occurs, in which case a null pointer is returned, and @{" errno " Link "errno"} is set to describe the error. See Also @{" errno " Link "errno"} , @{" fopen() " Link "fopen()"} , @{" feof() " Link "feof()"} , @{" ferror() " Link "ferror()"} , @{" fgetc() " Link "fgetc()"} , @{" fgets() " Link "fgets()"} , @{" getc() " Link "getc()"} @EndNode @Node "gmtime()" gmtime()-Unpack Greenwich Mean Time (GMT) Synopsis #include ut = gmtime(t); struct tm *ut; const time_t *t; Portability See Also @{" asctime() " Link "asctime()"} , @{" ctime() " Link "ctime()"} , @{" localtime() " Link "localtime()"} , @{" time() " Link "time()"} @EndNode @Node "isalnum()" isalnum()-Test if alphanumeric character Synopsis #include t = isalnum(c); int t; /* 0 if false, non-zero if true */ int c: /* character to test */ Portability Returns This function returns a non-zero value if c is an alphanumeric character, zero if not. See Also @{" __ctype " Link "__ctype"} @EndNode @Node "islpha()" isalpha()-Test if alphabetic character Synopsis #include t = isalpha(c); int t; /* 0 if false, non-zero if true */ int c: /* character to test */ Portability Returns This function returns a non-zero value if c is an alphabetic character, and a zero if not. See Also @{" __ctype " Link "__ctype"} @EndNode @Node "iscntrl()" iscntrl()-Test if control character Synopsis #include t = iscntrl(c); int t; /* 0 if false, non-zero if true */ int c: /* character to test */ Portability Returns This function returns a non-zero value if c is a control character, and a zero if not. See Also @{" __ctype " Link "__ctype"} @EndNode @Node "isdigit()" isdigit()-Test if decimal digit character (0 to 9) Synopsis #include t = isdigit(c); int t; /* 0 if false, non-zero if true */ int c: /* character to test */ Portability Returns This function returns a non-zero value if c is a decimal digit, and a zero if not. See Also @{" __ctype " Link "__ctype"} @EndNode @Node "isgraph()" isgraph()-Test if graphic character (anything but space, ' ') Synopsis #include t = isgraph(c); int t; /* 0 if false, non-zero if true */ int c: /* character to test */ Portability Returns This function returns a non-zero value if c is anything other than a space character (' '), and a zero if it is a space. See Also @{" __ctype " Link "__ctype"} @EndNode @Node "islower()" islower()-Test if lower case character Synopsis #include t = islower(c); int t; /* 0 if false, non-zero if true */ int c: /* character to test */ Portability Returns This function returns a non-zero value if c is a lower case letter, and a zero if not. See Also @{" __ctype " Link "__ctype"} @EndNode @Node "isprint()" isprint()-Test if printable character Synopsis #include t = isprint(c); int t; /* 0 if false, non-zero if true */ int c: /* character to test */ Portability Returns This function returns a non-zero value if c is any printable character other than space, and a zero if c is a space or a non-printable character (such as a control character). See Also @{" __ctype " Link "__ctype"} @EndNode @Node "ispunct()" ispunct()-Test if punctuation character Synopsis #include t = ispunct(c); int t; /* 0 if false, non-zero if true */ int c: /* character to test */ Portability Returns This function returns a non-zero value if c is anything other than a space or an alphanumeric character, and a zero if it is a space or an alphanumeric character. See Also @{" __ctype " Link "__ctype"} @EndNode @Node "isspace()" isspace()-Test if space character Synopsis #include t = isspace(c); int t; /* 0 if false, non-zero if true */ int c: /* character to test */ Portability Returns This function returns a non-zero value if c is a C space character (including ' ', '\n', '\f', etc.), and a zero if not. See Also @{" __ctype " Link "__ctype"} @EndNode @Node "freopen()" freopen()-Reopen a level 2 file Synopsis #include fpr = freopen(name, mode, fp); FILE *fpr; /* file pointer after re-opening */ const char *name; /* file name */ const char *mode; /* access mode */ FILE *fp; /* current file pointer */ Portability Returns If successful, this function returns the file pointer. Check the return code for null; the same errors as defined for @{" fopen() " Link "fopen()"} may occur. Also, for complete portability, do not assume that fpr and fp are identical. Use fpr to access the reopened file, not fp. See Also @{" fopen() " Link "fopen()"} , @{" fdopen() " Link "fdopen()"} @EndNode @Node "frexp()" frexp()-Split float value Synopsis #include f = frexp(v,xp); double f; /* fraction */ double v; /* value */ int *xp; /* exponent pointer */ Portability Returns This function returns the mantissa as a double whose absolute value is greater than or equal to 0.5 and less than 1.0. The exponent is returned as an integer whose absolute value is less than 1024. If the value v is zero, both returned values will be zero. See Also @{" fmod() " Link "fmod()"} , @{" ldexp() " Link "ldexp()"} , @{" __matherr() " Link "__matherr()"} , @{" modf() " Link "modf()"} @EndNode @Node "fscanf()" fscanf()-Formatted input conversions Synopsis #include n = fscanf(fp,fmt,arg1,arg2,...); int n; /* number of input items matched, or EOF */ FILE *fp; /* file pointer (fscanf() only) */ const char *fmt; /* format string */ ---- *argx; /* pointers to input data areas */ Portability Returns The function returns the number of assignments that were made. For example, a return value of 3 indicates that conversion results were assigned to arg1, arg2, and arg3. See Also @{" scanf() " Link "scanf()"} , @{" sscanf() " Link "sscanf()"} , @{" Formatted Input Specifiers() " Link "Formatted Input Specifiers"} @EndNode @Node "fseek()" fseek()-Set level 2 file position Synopsis #include error = fseek(fp,rpos,mode); int error; /* non-zero if error */ FILE *fp; /* file pointer returned from fopen() */ long int rpos; /* relative file position */ int mode; /* seek mode */ Portability Returns A value of -1 is returned if an error occurs. @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"} contain additional error information. See Also @{" errno " Link "errno"} , @{" fopen() " Link "fopen()"} , @{" ftell() " Link "ftell()"} , @{" lseek() " Link "lseek()"} , @{" _OSERR " Link "_OSERR"} , @{" rewind() " Link "rewind()"} @EndNode @Node "fsetpos()" fsetpos()-Reposition a file Synopsis #include x = fsetpos(fp,pos); int x; FILE *fp; const fpos_t *pos; Portability Returns If successful, fsetpos() returns 0. If it fails, fsetpos() returns a nonzero value and stores an appropriate error code in @{" errno " Link "errno"}. See Also @{" fgetpos() " Link "fgetpos()"} , @{" fopen() " Link "fopen()"} , @{" fseek() " Link "fseek()"} , @{" ftell() " Link "ftell()"} , @{" lseek() " Link "lseek()"} @EndNode @Node "ftell()" ftell()-Get level 2 file position Synopsis #include apos = ftell(fp); long int apos; /* absolute file position */ FILE *fp; /* file pointer */ Portability Returns For ftell(), an error is indicated by a return value of -1L. @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"} contain additional error information. See Also @{" errno " Link "errno"} , @{" fopen() " Link "fopen()"} , @{" _OSERR " Link "_OSERR"} , @{" lseek() " Link "lseek()"} , @{" tell() " Link "tell()"} @EndNode @Node "fwrite()" fwrite()-write blocks to a level 2 file Synopsis #include a = fwrite(b,bsize,n,fp); size_t a; /* actual number of blocks */ const void *b; /* pointer to first block */ size_t bsize; /* size of block in bytes */ size_t n; /* maximum number of blocks */ FILE *fp; /* file pointer */ Portability Returns This function returns the number of complete blocks that were processed. See Also @{" fopen() " Link "fopen()"} , @{" fclose() " Link "fclose()"} , @{" ferror() " Link "ferror()"} , @{" feof() " Link "feof()"} , @{" fgetc() " Link "fgetc()"} , @{" fputc() " Link "fputc()"} , @{" fread() " Link "fread()"} , @{" fseek() " Link "fseek()"} @EndNode @Node "getc()" getc()-Get a character from a file Synopsis #include c = getc(fp); int c; /* return character or code */ FILE *fp; /* file pointer */ Portability Returns If successful, the next input character is returned. Otherwise, this function returns EOF, which is defined in . In the event of an EOF return, error information can be found in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. Most programmers treat any EOF return as an indication of end-of-file. However, if you want to distinguish errors from an end-of-file condition, you should reset @{" errno " Link "errno"} before calling the function and then analyze its contents when you receive an EOF return. See Also @{" errno " Link "errno"} , @{" fgetc() " Link "fgetc()"} , @{" fgetchar() " Link "fgetchar()"} , @{" fopen() " Link "fopen()"} , @{" getchar() " Link "getchar()"} , @{" _OSERR " Link "_OSERR"} @EndNode @Node "getchar()" getchar()-Get a character from stdin Synopsis #include c = getchar(void); int c; /* return character or code */ Portability Returns If successful, the next input character is returned. Otherwise, the function returns EOF, which is defined in . In the event of an EOF return, error information can be found in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. See Also @{" errno " Link "errno"} , @{" fgetc() " Link "fgetc()"} , @{" fgetchar() " Link "fgetchar()"} , @{" fopen() " Link "fopen()"} , @{" getch() " Link "getch()"} , @{" _OSERR " Link "_OSERR"} @EndNode @Node "getenv()" getenv()-Get environment variable Synopsis #include var = getenv(name); char *var; /*environment variable pointer or NULL */ const char *name; /*environment variable name */ Portability Returns NULL is returned if name cannot be located in the current environment. NULL is defined in stddef.h. See Also @{" free() " Link "free()"} , @{" malloc() " Link "malloc()"} , @{" putenv() " Link "putenv()"} @EndNode @Node "fgets()" fgets()-Get string from a level 2 file Synopsis #include p = fgets(buffer,length,fp); char *p; /* buffer pointer or NULL */ char *buffer; /* buffer pointer */ int length; /* buffer length in bytes */ FILE *fp; /* file pointer */ Portability Returns If the end-of-file is hit before any bytes are read, a NULL pointer is returned. If an I/O error occurs, a NULL pointer is returned and additional information is placed in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. If no I/O error occurs and at least one byte was read from the file, the buffer argument is returned. See Also @{" errno " Link "errno"} , @{" fopen() " Link "fopen()"} , @{" feof() " Link "feof()"} , @{" ferror() " Link "ferror()"} , @{" fgetc() " Link "fgetc()"} , @{" fread() " Link "fread()"} , @{" getc() " Link "getc()"} , @{" gets() " Link "gets()"} , @{" _OSERR " Link "_OSERR"} @EndNode @Node "floor()" floor()-Get floor of a real number Synopsis #include x = floor(y); double x,y; Portability Returns The result is a real number. See Also @{" ceil() " Link "ceil()"} @EndNode @Node "__fmask" __fmask-Default protection bits for opening a file Synopsis extern unsigned long __fmask; Description This external integer indicates the default protection for any file routines. This flag has no effect on AmigaDOS I/O routines such as @{" Open() " Link "dos/Open()"}. The default protection is read, write, and delete. Portability @{" SAS/C " Link "Glossary - SASC"} See Also @{" creat() " Link "creat()"} , @{" fopen() " Link "fopen()"} , @{" open() " Link "open()"} , AmigaDOS @{" Open() " Link "dos/Open()"} @EndNode @Node "fmod()" fmod()-Float modulus operations Synopsis #include x = fmod(y,z); double x,y,z; Portability Returns This function returns y if z is 0. Otherwise, it returns a value that has the same sign as y, is less than z, and satisfies the relationship: y = (i * z) + x i is an integer. See Also @{" modf() " Link "modf()"} @EndNode @Node "fopen()" fopen()-open a level 2 file Synopsis #include fp = fopen(name,"mode"); FILE *fp; /* file pointer */ const char *name; /* file name */ const char *mode; /* access mode string */ Portability Returns A null pointer is returned if the file cannot be opened. Consult @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"} for detailed error information. See Also @{" fclose() " Link "fclose()"} , @{" fdopen() " Link "fdopen()"} , @{" fgetc() " Link "fgetc()"} , @{" fgets() " Link "fgets()"} , @{" fputc() " Link "fputc()"} , @{" fputs() " Link "fputs()"} , @{" fread() " Link "fread()"} , @{" freopen() " Link "freopen()"} , @{" fwrite() " Link "fwrite()"} , @{" open() " Link "open()"} @EndNode @Node "fprintf()" fprintf()-Formatted print Synopsis #include length = fprintf(fp,fmt,arg1,arg2,...); int length; /* number of characters generated */ FILE *fp; /* file pointer */ const char *fmt; /* format string */ *arg; /* arguments */ Portability Returns This function returns the number of output characters generated. If an error occurs, fprintf() returns a negative value and places additional information in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. See Also @{" errno " Link "errno"} , @{" fscanf() " Link "fscanf()"} , @{" _OSERR " Link "_OSERR"} , @{" printf() " Link "printf()"} , @{" scanf() " Link "scanf()"} , @{" sprintf() " Link "sprintf()"} , @{" sscanf() " Link "sscanf()"} , @{" Formatted Input Specifiers " Link "Formatted Input Specifiers"} , @{" Formatted Output Specifiers " Link "Formatted Output Specifiers"} @EndNode @Node "fputc()" fputc()-Put a character to a level 2 file Synopsis #include r = fputc(c,fp); int r; /* EOF or c */ int c; /* character to be output */ FILE *fp; /* level 2 file pointer */ Portability Returns If successful, this function returns the character c; otherwise, it returns EOF. For disk files, an EOF return usually means that the disk is full. However, this type of return can also occur if the device is write-protected or if a write error occurs. In any case, additional error information can be found in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. See Also @{" errno " Link "errno"} , @{" fopen() " Link "fopen()"} , @{" fputchar() " Link "fputchar()"} , @{" _OSERR " Link "_OSERR"} , @{" putc() " Link "putc()"} , @{" putchar() " Link "putchar()"} @EndNode @Node "fputs()" fputs()-Put string to level 2 file Synopsis #include error = fputs(s,fp); int error; /* non-zero if error */ const char *s; /* string pointer */ FILE *fp; /* file pointer */ Portability Returns If an error occurs, the return value is EOF; otherwise, it is 0. Additional error information can be found in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. See Also @{" errno " Link "errno"} , @{" ferror() " Link "ferror()"} , @{" fopen() " Link "fopen()"} , @{" fputc() " Link "fputc()"} @{" _OSERR " Link "_OSERR"} , @{" puts() " Link "puts()"} @EndNode @Node "fread()" fread()-read and write blocks Synopsis #include a = fread(b,bsize,n,fp); size_t a; /* actual number of blocks */ void *b; /* pointer to first block */ size_t bsize; /* size of block in bytes */ size_t n; /* maximum number of blocks */ FILE *fp; /* file pointer */ Portability Returns This function returns the number of complete blocks that were read. See Also @{" fopen() " Link "fopen()"} , @{" fclose() " Link "fclose()"} , @{" ferror() " Link "ferror()"} , @{" feof() " Link "feof()"} , @{" fgetc() " Link "fgetc()"} , @{" fputc() " Link "fputc()"} , @{" fseek() " Link "fseek()"} , @{" fwrite() " Link "fwrite()"} @EndNode @Node "free()" free()-free memory Synopsis #include void free(b); void *b; /* block pointer */ Portability See Also @{" calloc() " Link "calloc()"} , @{" getmem() " Link "getmem()"} , @{" malloc() " Link "malloc()"} , @{" rbrk() " Link "rbrk()"} , @{" realloc() " Link "realloc()"} , @{" rlsmem() " Link "rlsmem()"} , @{" sbrk() " Link "sbrk()"} @EndNode @Node "difftime()" difftime()-Compute the difference of two times Synopsis #include x = difftime(time2,time1); double x; time_t time1, time2; Portability Returns difftime() returns the difference between two times, in seconds. See Also @{" time() " Link "time()"} @EndNode @Node "div()" div()-Compute quotient and remainder Synopsis #include x = div(y, z); div_t x; /* quotient and remainder */ int y; /* numerator */ int z; /* denominator */ Portability Returns div() returns a structure of type div_t, which contains both the quotient and remainder. The return value is such that numer = quot * denom + rem The sign of rem is the same as the sign of numer. See Also @{" ldiv() " Link "ldiv()"} @EndNode @Node "exit()" exit()-Terminate program execution Synopsis #include void exit(code); int code; Portability See Also @{" longjmp() " Link "longjmp()"} @EndNode @Node "exp()" exp()-exponential function Synopsis #include r = exp(x); double r, x; Portability Returns This function returns a double containing the calculated exponential. See Also @{" log() " Link "log()"}, @{" __matherr() " Link "__matherr()"} @EndNode @Node "fabs()" fabs()-Float/double absolute value Synopsis #include ad = fabs(d); double ad,d; Portability Returns This function returns a double containing the absolute value of the argument. See Also @{" abs() " Link "abs()"} , @{" iabs() " Link "iabs()"} , @{" labs() " Link "labs()"} @EndNode @Node "fclose()" fclose()-close a level 2 file Synopsis #include ret = fclose(fp); int ret; /* return code */ FILE *fp; /* file pointer for file to be closed */ Portability Returns If successful, fclose() returns 0. This function returns EOF to indicate an error. If EOF is returned, additional error information can be found in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. See Also @{" errno " Link "errno"} , @{" fopen() " Link "fopen()"} , @{" open() " Link "open()"} , @{" _OSERR " Link "_OSERR"} @EndNode @Node "feof()" feof()-Check for level 2 end-of-file Synopsis #include ret = feof(fp); int ret; /* non-zero if condition is true */ FILE *fp; /* file pointer */ Portability Returns This function returns non-zero value if the specified file pointer is at end-of-file. If not, this function returns a 0. See Also @{" ferror() " Link "ferror()"} @EndNOde @Node "ferror()" ferror()-Check for level 2 error Synopsis #include ret = ferror(fp); int ret; /* non-zero if condition is true */ FILE *fp; /* file pointer */ Portability Returns The return value is 0 if no error has been set. If an error indicator was set, a non-zero value is returned. See Also @{" clearerr() " Link "clearerr()"} , @{" feof() " Link "feof()"} @EndNode @Node "fflush()" fflush()-Flush level 2 output buffer Synopsis #include ret = fflush(fp); int ret; /* return code */ FILE *fp; /* file pointer */ Portability Returns If an error occurs, the return value is EOF. The appropriate error code is placed into @{" errno " Link "errno"}, and additional information is placed in @{" _OSERR " Link "_OSERR"}. See Also @{" errno " Link "errno"} , @{" fclose() " Link "fclose()"} , @{" fcloseall() " Link "fcloseall()"} , @{" flushall() " Link "flushall()"} , @{" fopen() " Link "fopen()"} , @{" _OSERR " Link "_OSERR"} @EndNode @Node "fgetpos()" fgetpos()-Get the current file position Synopsis #include x = fgetpos(f, pos); int x; FILE *f; fpos_t *pos; Portability Returns If successful, fgetpos() returns 0. If it fails, fgetpos() returns a nonzero value and stores an appropriate error code in @{" errno " Link "errno"}. See the description of @{" errno " Link "errno"} in Chapter 6 of the library reference for the list of possible values. See Also @{" fseek() " Link "fseek()"}, @{" fsetpos() " Link "fsetpos()"}, @{" ftell() " Link "ftell()"} , @{" lseek() " Link "lseek()"} @EndNode @Node "fgetc()" fgetc()-Get a character from a file Synopsis #include c = fgetc(fp); int c; /* return character or code */ FILE *fp; /* file pointer */ Portability Returns If successful, the next input character is returned. Otherwise, the function returns EOF, which is defined in . In the event of an EOF return, error information can be found in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. See Also @{" errno " Link "errno"} , @{" fgetchar() " Link "fgetchar()"} , @{" fputc() " Link "fputc()"} , @{" getc() " Link "getc()"} , @{" getch() " Link "getch()"} , @{" getchar() " Link "getchar()"} , @{" fopen() " Link "fopen()"} , @{" ungetc() " Link "ungetc()"} , @{" _OSERR " Link "_OSERR"} @EndNode @Node "abort()" abort()-abort the current process Synopsis #include void abort(void); Portability See Also @{" exit() " Link "exit()"} , @{" __exit() " Link "__exit()"} , @{" raise() " Link "raise()"} , @{" _XCEXIT() " Link "_XCEXIT()"} @EndNode @Node "abs()" abs()-absolute value Synopsis #include ax = abs(x); type x; type ax; Portability Returns The return value is the absolute value of the argument. See Also @{" fabs() " Link "fabs()"} , @{" iabs() " Link "iabs()"} , @{" labs() " Link "labs()"} @EndNode @Node "acos()" acos()-Arccosine function Synopsis #include r = acos(x); double r; /* result */ double x; /* angle */ Portability Returns This function returns the arccosine of the angle expressed in radians. See Also @{" __matherr() " Link "__matherr()"}, @{" cos() " Link "cos()"} @EndNode @Node "asctime()" asctime()-Generate ASCII time string Synopsis #include s = asctime(t); char *s; /*points to time string */ const struct tm *t; /*points to time structure */ Portability Returns This function returns an ASCII string of exactly 26 characters having the form: "DDD MMM dd hh:mm:ss YYYY\n\0" DDD is the day of the week, MMM is the month, dd is the day of the month, hh:mm:ss is the hour:minute:seconds, and YYYY is the year. An example is: "Wed Sep 04 15:13:22 1985\n\0" The time pointer returned by the function refers to a static data area that is shared by both @{" ctime() " Link "ctime()"} and asctime. See Also @{" ctime() " Link "ctime()"}, @{" gmtime() " Link "gmtime()"}, @{" localtime() " Link "localtime()"}, @{" strftime() " Link "strftime()"} @EndNode @Node "asin()" asin()-Arcsine function Synopsis #include r = asin(x); double r; /* result */ double x; /* angle */ Portability Returns This function returns the arcsine of the argument expressed in radians. See Also @{" __matherr() " Link "__matherr()"} , @{" sin() " Link "sin()"} @EndNode @Node "assert()" assert()-assert program validity Synopsis #include assert(x); __assert(x,file,line); int x; const char *file; /* source file name */ int *line; /* source line number */ Portability See Also @{" stcsma() " Link "stcsma()"} , @{" stcpma() " Link "stcpma()"} , @{" stcpm() " Link "stcpm()"} @EndNode @Node "atan()" atan()-Arctangent function Synopsis #include r = atan(x); double r; /* result */ double x; /* angle */ Portability Returns This function returns the arctangent of the argument expressed in radians. See Also @{" atan2() " Link "atan2()"} , @{" __matherr() " Link "__matherr()"} , @{" tan() " Link "tan()"} @EndNode @Node "atan2()" atan2()-Arctangent of x/y Synopsis #include r = atan2(x,y); double r; /* result; */ double x,y; /* angle */ Portability Returns This function returns the arctangent of the argument expressed in radians. See Also @{" atan() " Link "atan()"} , @{" __matherr() " Link "__matherr()"} , @{" tan() " Link "tan()"} @EndNode @Node "atexit()" atexit()-Set an exit trap Synopsis #include error = atexit(func); int error; /* non-zero for success */ void (*func)(void); /* trap function pointer */ Portability Returns A zero is returned for success and a non-zero value is returned if an error is encountered. See Also @{" exit() " Link "exit()"} @EndNode @Node "atof()" atof()-Convert ASCII to float Synopsis #include d = atof(p); double d; /* floating point result */ const char *p; /* input string pointer */ Portability Returns This function returns the double equivalent of the ASCII string. See Also @{" atoi() " Link "atoi()"} , @{" atol() " Link "atol()"} , @{" stcd_i() " Link "stcd_i()"} , @{" stcd_l() " Link "stcd_l()"} , @{" strtod() " Link "strtod()"} @EndNode @Node "atoi()" atoi()-Convert ASCII to integer Synopsis #include x = atoi(s); int x; const char *s; Portability Returns This function returns the integer equivalent of the ASCII string. See Also @{" atol() " Link "atol()"} , @{" atof() " Link "atof()"} , @{" stcd_i() " Link "stcd_i()"} , @{" stcd_l() " Link "stcd_l()"} , @{" strtod() " Link "strtod()"} , @{" strtol() " Link "strtol()"} @EndNode @Node "atol()" atol()-Convert ASCII to long integer Synopsis #include y = atol(s); long int y; const char *s; Portability Returns This function returns the long integer equivalent of the ASCII string. See Also @{" atoi() " Link "atoi()"} , @{" atof() " Link "atof()"} , @{" stcd_i() " Link "stcd_i()"} , @{" stcd_l() " Link "stcd_l()"} , @{" strtod() " Link "strtod()"} , @{" strtol() " Link "strtol()"} @EndNode @Node "bsearch()" bsearch()-Perform a binary search Synopsis #include void *bsearch(srch, array, n, size,cmp); const void *srch; /* object searched for */ const void *array; /* pointer to array to search */ size_t n; /* number of members of array */ size_t size; /* size of each element */ int (*cmp)(const void *, const void *)); /* pointer to comparison function */ Portability Returns bsearch() returns a pointer to the element that matches the search value. If no match can be found, NULL is returned. See Also @{" qsort() " Link "qsort()"} @EndNode @Node "calloc()" calloc()-Allocate level 3 memory allocation Synopsis #include b = calloc(nelt,esize); void *b; /* block pointer */ size_t nelt; /* number of elements */ size_t esize; /* element size */ Portability Returns A null pointer is returned if there is not enough space for the requested block. See Also @{" getmem() " Link "getmem()"} , @{" rlsmem() " Link "rlsmem()"} , @{" sbrk() " Link "sbrk()"} , @{" rbrk() " Link "rbrk()"} , @{" malloc() " Link "malloc()"} ,@{" realloc() " Link "realloc()"} ,@{" free() " Link "free()"} @EndNode @Node "ceil()" ceil()-Get floating point limits Synopsis #include x = ceil(y); double x,y; Portability Returns The result is a real number. See Also @{" floor() " Link "floor()"} @EndNode @Node "clearerr()" clearerr()-Clear level 2 I/O error flag Synopsis #include void clearerr(fp); FILE *fp; /* file pointer */ Portability See Also @{" clrerr() " Link "clrerr()"} , @{" ferror() " Link "ferror()"} @EndNode @Node "clock()" clock()-Measure program processor time Synopsis #include x = clock(void); clock_t x; Portability Returns clock() returns the number of seconds since the base time. If an accurate value cannot be returned, (clock_t)-1 is returned. See Also @{" time() " Link "time()"} , @{" system() " Link "system()"} @EndNode @Node "cos()" cos()-cosine function Synopsis #include r = cos(x); double r; /* result */ double x; /* angle */ Portability Returns This function returns the cosine of the argument. See Also @{" __matherr() " Link "__matherr()"} @EndNode @Node "cosh()" cosh()-Hyperbolic cosine function Synopsis #include r = cosh(x); double r; /* result */ double x; /* angle */ Portability Returns This function returns the hyperbolic cosine of the argument expressed in radians. See Also @{" exp() " Link "exp()"} , @{" __matherr() " Link "__matherr()"} @EndNode @Node "ctime()" ctime()-Convert time value to string Synopsis #include s = ctime(t); char *s; /* points to time string */ const time_t *t; /* points to time value */ Portability Returns This function returns an ASCII string of exactly 26 characters having the form: "DDD MMM dd hh:mm:ss YYYY\n\0" DDD is the day of the week, MMM is the month, dd is the day of the month, hh:mm:ss is the hour:minute:seconds, and YYYY is the year. An example is: "Wed Sep 04 15:13:22 1985\n\0" The time pointer returned by the function refers to a static data area that is shared by both ctime() and @{" asctime() " Link "asctime()"}. See Also @{" asctime() " Link "asctime()"} , @{" gmtime() " Link "gmtime()"} , @{" localtime() " Link "localtime()"} , @{" strftime() " Link "strftime()"} , @{" time() " Link "time()"} @EndNode @Node "ungetc()" ungetc()-Push input character back Synopsis #include r = ungetc(c, fp); int r; /* return character or code */ int c; /* character to be pushed back */ FILE *fp; /* file pointer */ Portability Returns Normally, ungetc() returns the character that was pushed back. However, if the end-of-file has been reached or if no characters have been read yet, the value EOF is returned. See Also @{" getc() " Link "getc()"} @EndNode @Node "va_arg()" va_arg()-access an argument from a varying-length argument list Synopsis #include (arg_type) va_arg(va_list ap, arg_type); Portability Returns This macro returns the value of the next argument in the list. The type is always the same as the second argument to va_arg(). See Also @{" va_start() " Link "va_start()"} , @{" va_end() " Link "va_end()"} @EndNode @Node "va_end()" va_end()-End varying-length argument list processing Synopsis #include void va_end(va_list ap); Portability See Also @{" va_start() " Link "va_start()"} , @{" va_arg() " Link "va_arg()"} @EndNode @Node "va_start()" va_start()-Begin varying-length argument list processing Synopsis #include void va_start(va_list ap, arg_name); Portability See Also @{" va_arg() " Link "va_arg()"} , @{" va_end() " Link "va_end()"} @EndNode @Node "vfprintf()" vfprintf()-Varargs formatted write to a file Synopsis #include #include n = vfprintf(fp, ctl, args); int n; /* number of characters written */ /* or -1 for error */ FILE *fp; /* file to be written to */ const char *ctl; /* control string specifying formatting */ va_list args; /* items to be formatted */ Portability Returns This function returns the number of characters written or, in the case of an error, a -1. See Also @{" fprintf() " Link "fprintf()"} , @{" printf() " Link "printf()"} , @{" sprintf() " Link "sprintf()"} , @{" Formatted Output Specifiers " Link "Formatted Output Specifiers"} @EndNode @Node "vprintf()" vprintf()-Varargs formatted write to standard output Synopsis #include #include x = vprintf(ctl, args); int x; /* number of characters written */ /* or -1 for error */ const char *ctl; /* control string specifying formatting */ va_list args; /* items to be formatted */ Portability Returns This function returns the number of characters written or, in the case of an error, a -1. See Also @{" fprintf() " Link "fprintf()"} , @{" printf() " Link "printf()"} , @{" sprintf() " Link "sprintf()"} , @{" Formatted Output Specifiers " Link "Formatted Output Specifiers"} @EndNode @Node "vsprintf()" vsprintf()-Varargs formatted write to string Synopsis #include #include x = vsprintf(buf, ctl, args); int x; /* number of characters placed in the */ /* output buffer */ char *buf; /* String for resulting image */ const char *ctl; /* control string specifying formatting */ va_list args; /* items to be formatted */ Portability Returns This function returns the number of characters placed in the output buffer (excluding the terminating null byte). See Also @{" fprintf() " Link "fprintf()"} , @{" printf() " Link "printf()"} , @{" sprintf() " Link "sprintf()"} , @{" Formatted Output Specifiers " Link "Formatted Output Specifiers"} @EndNode @Node "wcstombs()" wcstombs()-Convert a wide-character string to a multibyte string Synopsis #include length = wcstombs(s, pwcs, n); size_t length; /* length or state information */ char *s; /* pointer to characters */ const wchar_t *pwcs; /* pointer to wide-character string */ size_t n; /* maximum number of characters to look at */ Portability See Also @{" wctomb() " Link "wctomb()"} , @{" mblen() " Link "mblen()"} @EndNode @Node "wctomb()" wctomb()-Map wide character to multibyte character Synopsis #include length = wctomb(s, wc); int length; /* length or state information */ char *s; /* pointer to characters or NULL */ wchar_t wc; /* wide character */ Portability See Also @{" wcstombs() " Link "wcstombs()"} , @{" mblen() " Link "mblen()"} @EndNode @Node "Formatted Input Specifiers" Specifier Meaning --------- ------- d,i signed integer o octal unsigned integer u unsigned integer x hexadecimal unsigned integer e,f,g floating point s any string of non-whitespace characters [ any non-empty sequence of characters from specified set; can optionally include leading ^ to specify NOT in set c any character p pointer value n number of characters read from input % exact match for percent (%) character NOTE: Input whitespace characters are skipped, unless the specification contains a [, c, or n specifier. See Also @{" fscanf() " Link "fscanf()"} , @{" scanf() " Link "scanf()"} , @{" sscanf() " Link "sscanf()"} @EndNode @Node "Formatted Output Specifiers" Specifier Meaning --------- ------- d,i 'int' argument is converted to a signed decimal string o 'unsigned int' argument is converted to octal string u 'unsigned int' argument is converted to decimal string x 'unsigned int' argument is converted to lowercase hexadecimal string X 'unsigned int' argument is converted to uppercase hexadecimal string f 'double' argument is converted to a decimal string e,E,g,G 'double' argument is converted to a decimal string using scientific notation c 'int' argument is converted to an unsigned char s argument is a pointer to a NULL terminated array of character type (C-style string) p argument is printed as a pointer, using lowercase hexadecimal characters P argument is printed as a pointer, using uppercase hexadecimal characters n argument is a pointer to an integer into which will be written the number of characters output so far % a percent sign (%) will be written See Also @{" fprintf() " Link "fprintf()"} , @{" printf() " Link "printf()"} , @{" sprintf() " Link "sprintf()"} , @{" vfprintf() " Link "vfprintf()"} @{" vprintf() " Link "vprintf()"} , @{" vsprintf() " Link "vsprintf()"} @EndNode @Node "Glossary" @{" SAS/C " Link "Glossary - SASC"} @{" UNIX " Link "Glossary - UNIX"} @{" XENIX " Link "Glossary - XENIX"} @EndNode @Node "Glossary - ANSI" American National Standards Institute. Functions with this portability X3J11/90-013. @EndNode @Node "strncat()" strncat()-Concatenate strings, length limited Synopsis #include p = strncat(to,from,n); char *p; /* same as destination string pointer */ char *to; /* destination string pointer */ const char *from; /* source string pointer */ size_t n; /* maximum source length */ Portability Returns This function returns a pointer that is the same as the first argument. See Also @{" stpcpy() " Link "stpcpy()"} , @{" strcat() " Link "strcat()"} @EndNode @Node "strncmp()" strncmp()-Compare strings, length-limited Synopsis #include x = strncmp(a,b,n); int x; /* comparison result */ const char *a,*b; /* strings being compared */ size_t n; Portability Returns This function returns a 0 if both strings are equal. If s1 is logically less than s2, the return value is less than 0. If s1 is logically greater than s2, the return value is greater than 0. See Also @{" strcmp() " Link "strcmp()"} , @{" strcmpi() " Link "strcmpi()"} , @{" stricmp() " Link "stricmp()"} , @{" strnicmp() " Link "strnicmp()"} @EndNode @Node "strncpy()" strncpy()-Copy string, length-limited Synopsis #include p = strncpy(to,from,n); char *p; /* same as destination pointer */ char *to; /* destination pointer */ const char *from; /* source pointer */ size_t n; /* maximum source length */ Portability Returns This function returns a pointer that is the same as the destination pointer. See Also @{" stccpy() " Link "stccpy()"} , @{" stpcpy() " Link "stpcpy()"} , @{" strcpy() " Link "strcpy()"} @EndNode @Node "strpbrk()" strpbrk()-Find break character in string Synopsis #include p = strpbrk(s,b); char *p; /* points to break character in s */ const char *s; /* string to be scanned */ const char *b; /* break characters */ Portability Returns If no character from b is found in s, a null pointer is returned. Otherwise, p is a pointer to the first break character. See Also @{" stpbrk() " Link "stpbrk()"} , @{" strspn() " Link "strspn()"} , @{" strcspn() " Link "strcspn()"} @EndNode @Node "strrchr()" strrchr()-Locate the last occurrence of a character in a string Synopsis #include p = strrchr(s,c); char *p; /* updated string pointer */ const char *s; /* input string pointer */ int c; /* character to be located */ Portability See Also @{" stpchr() " Link "stpchr()"} , @{" stpchrn() " Link "stpchrn()"} , @{" strchr() " Link "strchr()"} @EndNode @Node "strspn()" strspn()-Measure span of characters in set Synopsis #include length = strspn(s,b); size_t length; /* span length in bytes */ const char *s; /* points to string being scanned */ const char *b; /* points to character set string */ Portability See Also @{" stcis() " Link "stcis()"} , @{" stcisn() " Link "stcisn()"} , @{" strcspn() " Link "strcspn()"} @EndNode @Node "strstr()" strstr()-Locate a substring inside of a string Synopsis #include p = strstr(s1, s2); char *p; /* pointer to substring in string.*/ const char *s1; /* string to search in. */ const char *s2; /* substring to search for. */ Portability Returns This function returns a pointer to substring s2 within s1. If it cannot find the substring, it returns a null pointer. See Also @{" strrchr() " Link "strrchr()"} , @{" strchr() " Link "strchr()"} , @{" strmid() " Link "strmid()"} @EndNode @Node "strtod()" strtod()-Convert string to double Synopsis #include d = strtod(nptr, endptr); double d; /* converted number */ const char *nptr; /* string to convert */ char **endptr; /* pointer to end of string */ Portability Returns This function returns the converted double. If it is unable to perform conversion on the input source string, it returns a value of 0. For values too large or too small to fit in a double, it returns a value than is plus or minus HUGE_VAL and sets @{" errno " Link "errno"} to ERANGE. In the case of an underflow, it returns zero, and @{" errno " Link "errno"} is set to ERANGE. See Also @{" errno " Link "errno"} , @{" scanf() " Link "scanf()"} @EndNode @Node "strtok()" strtok()-Get a token Synopsis #include t = strtok(s,b); char *t; /* token pointer */ char *s; /* input string pointer or NULL */ const char *b; /* break character string pointer */ Portability Returns A null pointer is returned when there are no more tokens. See Also @{" stptok() " Link "stptok()"} , @{" strcspn() " Link "strcspn()"} , @{" strspn() " Link "strspn()"} @EndNode @Node "strtol()" strtol()-Convert string to long integer Synopsis #include r = strtol(p,np,base); long int r; /* result */ const char *p; /* string pointer */ char **np; /* returns updated string pointer */ int base; /* conversion base */ Portability Returns This function returns the converted value. If it cannot do the conversion, it returns a zero. If the converted value would have been too large or small to fit in a long, it returns LONG_MAX or LONG_MIN and sets @{" errno " Link "errno"} to ERANGE. See Also @{" errno " Link "errno"}, @{" strtoul() " Link "strtoul()"} @EndNode @Node "strtoul()" strtoul()-Convert string to unsigned long integer Synopsis #include r = strtoul(p,np,base); unsigned long int r; /* result */ const char *p; /* string pointer */ char **np; /* returns updated string pointer */ int base; /* conversion base */ Portability Returns This function returns the converted value. If it cannot do the conversion, it returns a zero. If the converted value would have been too large to fit in an unsigned long, it returns ULONG_MAX and sets @{" errno " Link "errno"} to ERANGE. See Also @{" errno " Link "errno"}, @{" strtol() " Link "strtol()"} @EndNode @Node "strxfrm()" strxfrm()-Transform a string Synopsis #include len = strxfrm(s1, s2, n); size_t len; /* length of transformed string */ char *s1; /* pointer to transformed string */ const char *s2; /* string to transform */ size_t n; /* max() characters in transformed string */ Portability Returns This function returns the length of the transformed string (excluding the null termination character). If a value is greater than n, then the transformation could not fit in the output array, and the contents of the output array is indeterminate. See Also @{" setlocale() " Link "setlocale()"} , @{" strcoll() " Link "strcoll()"} @EndNode @Node "_STRICT_ANSI" Synopsis #define _STRICT_ANSI Portibility @{" SAS/C " Link "Glossary - SASC"} Description an underscore followed by a capital letter, or an underscore followed by another underscore. Defining this symbol will prevent the definition of any symbols from standard. @EndNode @Node "system()" system()-Call system command processor Synopsis #include error = system(cmd); int error; /* non-zero if error */ const char *cmd; /* command string */ Portability Returns If the command processor cannot be invoked, a value of -1 is returned, and additional error information can be found in @{" errno " Link "errno"} and @{" _OSERR " Link "_OSERR"}. Otherwise, the function returns the value passed back by the command processor. See Also @{" errno " Link "errno"} , @{" _OSERR " Link "_OSERR"} @EndNode @Node "tan()" tan()-tangent function Synopsis #include r = tan(x); double r; /* result */ double x; /* angle */ Portability See Also @{" __matherr() " Link "__matherr()"} @EndNode @Node "tanh()" tanh()-Hyperbolic tangent function Synopsis #include r = tanh(x); double r; /* result */ double x; /* angle */ Portability See Also @{" __matherr() " Link "__matherr()"} @EndNode @Node "time()" time()-Get system time in seconds Synopsis #include timeval = time(timeptr); time_t timeval; /* time value */ time_t *timeptr; /* pointer to time value storage */ Portability See Also @{" asctime() " Link "asctime()"} , @{" ctime() " Link "ctime()"} , @{" gmtime() " Link "gmtime()"} , @{" localtime() " Link "localtime()"} , @{" __tzset() " Link "__tzset()"} @EndNode @Node "tmpfile()" tmpfile()-open a temporary file stream Synopsis #include fp = tmpfile(void); FILE *fp; /* pointer to temporary file stream */ Portability Returns This function returns a file handle for a file that can be read or written. When this file is closed, it is automatically deleted. See Also @{" open() " Link "open()"} , @{" close() " Link "close()"} , @{" tmpnam() " Link "tmpnam()"} @EndNode @Node "tmpnam()" tmpnam()-create a temporary file name Synopsis #include name = tmpnam(b); char *name; /* pointer to temporary file name */ char *b; /* pointer to name buffer or NULL */ Portability Returns This function returns a pointer to a temporary file name. See Also @{" tmpfile() " Link "tmpfile()"} @EndNode @Node "tolower()" tolower()-Convert character to lowercase Synopsis #include cc = tolower(c); int cc; /* converted character */ int c; /* character to convert */ Portability See Also @{" __ctype " Link "__ctype"} , @{" islower() " Link "islower()"} , @{" strlwr() " Link "strlwr()"} @EndNode @Node "toupper()" toupper()-Convert character to uppercase Synopsis #include cc = toupper(c); int cc; /* converted character */ int c; /* character to convert */ Portability See Also @{" __ctype " Link "__ctype"} , @{" isupper() " Link "isupper()"} , @{" strupr() " Link "strupr()"} @EndNode @Node "setbuf()" setbuf()-Set buffer mode for a level 2 file Synopsis #include void setbuf(fp,buff); FILE *fp; /* file pointer */ const char *buff; /* buffer pointer */ Portability See Also @{" fopen() " Link "fopen()"} , @{" setnbf() " Link "setnbf()"} , @{" setvbuf() " Link "setvbuf()"} @EndNode @Node "setjmp()" setjmp()-Set long jump parameters Synopsis #include ret = setjmp(save); int ret; /* return code */ jmp_buf save; /* address of save area */ Portability Returns A return code of 0 indicates that this is the initial call to save the stack. A non-zero return code indicates that @{" longjmp() " Link "longjmp()"} has been executed. See Also @{" longjmp() " Link "longjmp()"} @EndNode @Node "setlocale()" setlocale()-Set locale information for program Synopsis #include ret = setlocale(category, locale); char *ret; /* Pointer to the selected locale portion */ int category; /* Names the portion of the locale to be */ /* selected */ const char *locale; /* Identifies the type of environment */ Portability Returns If it finds the selected environment, this function returns a pointer to a string associated with the requested category. If it cannot find the environment, it returns a null, and the program's locale is not changed. This string is considered read-only and is valid until the next call to this function. See Also @{" readlocale() " Link "readlocale()"} , @{" localeconv() " Link "localeconv()"} @EndNode @Node "setvbuf()" setvbuf()-Set variable buffer for level 2 file Synopsis #include error = setvbuf(fp,buff,type,size); int error; /* 0 if successful */ FILE *fp; /* file pointer */ const char *buff; /* buffer pointer */ int type; /* type of buffering */ size_t size; /* buffer size in bytes */ Portability Returns This function returns a non-zero error code if type or size is invalid. See Also @{" fopen() " Link "fopen()"} , @{" setbuf() " Link "setbuf()"} , @{" setnbf() " Link "setnbf()"} @EndNode @Node "signal()" signal()-Establish event traps Synopsis #include oldfun = signal(sig,newfun); void (*oldfun)(int); /* old trap function */ int sig; /* signal() number */ void (*newfun)(int); /* new trap function */ Portability Returns If the trap can be established, the signal() function returns a pointer to the previous handler function. Otherwise, it returns SIG_ERR and places error information in @{" errno " Link "errno"}. @EndNode @Node "sin()" sin()-sine function Synopsis #include r = sin(x); double r; /* result */ double x; /* angle */ Portability See Also @{" cos() " Link "cos()"} , @{" cosh() " Link "cosh()"} , @{" __matherr() " Link "__matherr()"} , @{" sinh() " Link "sinh()"} @EndNode @Node "sinh()" sinh()-Hyperbolic sine function Synopsis #include r = sinh(x); double r; /* result */ double x; /* angle */ Portability See Also @{" cos() " Link "cos()"} , @{" cosh() " Link "cosh()"} , @{" __matherr() " Link "__matherr()"} , @{" sin() " Link "sin()"} @EndNode @Node "sprintf()" sprintf()-Formatted print to a string Synopsis #include length = sprintf(s,fmt,arg1,arg2,...); int length; /* number of characters generated */ char *s; /* pointer to a character string */ const char *fmt; /* format string */ arg /* arguments */ Portability Returns This function returns the number of output characters generated. This number does not include the terminating null byte. See Also @{" fprintf() " Link "fprintf()"} , @{" printf() " Link "printf()"} , @{" Formatted Output Specifiers " Link "Formatted Output Specifiers"} @EndNode @Node "sqrt()" sqrt()-Square root function Synopsis #include r = sqrt(x); double r, x; Portability See Also @{" __matherr() " Link "__matherr()"} , @{" pow() " Link "pow()"} , @{" pow2() " Link "pow2()"} @EndNode @Node "srand()" srand()-Set seed for rand() function Synopsis #include void srand(seed); unsigned int seed; /* random number seed */ Portability See Also @{" drand48() " Link "drand48()"} , @{" erand48() " Link "erand48()"} , @{" lrand48() " Link "lrand48()"} , @{" nrand48() " Link "nrand48()"} , @{" jrand48() " Link "jrand48()"} , @{" rand() " Link "rand()"} , @{" srand48() " Link "srand48()"} @EndNode @Node "sscanf()" sscanf()-Formatted input conversions Synopsis #include n = sscanf(ss,fmt,arg1,arg2,...); int n; /* number of input items matched, or EOF */ const char *ss; /* input string (sscanf() only) */ const char *fmt; /* format string */ ---- *arg[]; /* pointers to input data areas */ Portability Returns This function returns the number of assignments that were made. For example, a return value of three indicates that conversion results were assigned to arg1, arg2, and arg3. See Also @{" fscanf() " Link "fscanf()"} , @{" scanf() " Link "scanf()"} , @{" Formatted Input Specifiers " Link "Formatted Input Specifiers"} @EndNode @Node "stpcpy()" stpcpy()-Copy one string to another Synopsis #include np = stpcpy(to,from); char *np; /* points to end of destination string */ char *to; /* destination pointer */ const char *from; /* source pointer */ Portability @{" SAS/C " Link "Glossary - SASC"} Returns This function returns a pointer to the end of the destination string, which is useful when you are building a string up from several pieces. function returns a pointer to the null byte after the to string. See Also @{" stccpy() " Link "stccpy()"} , @{" strcpy() " Link "strcpy()"} , @{" strncpy() " Link "strncpy()"} @EndNode @Node "strcat()" strcat()-Concatenate strings Synopsis #include p = strcat(to,from); char *p; /* same as destination string pointer */ char *to; /* destination string pointer */ const char *from; /* source string pointer */ Portability Returns This function returns a pointer that is the same as the first argument. See Also @{" strncat() " Link "strncat()"} , @{" stpcpy() " Link "stpcpy()"} @EndNode @Node "strchr()" strchr()-Find character in string Synopsis #include p = strchr(s,c); char *p; /* updated string pointer */ const char *s; /* input string pointer */ int c; /* character to be located */ Portability Returns A null pointer is returned if the input string is empty or if the specified character is not found. Otherwise, this function returns a pointer to the first matching character in s. See Also @{" strchr() " Link "strchr()"} , @{" stpchrn() " Link "stpchrn()"} , @{" strrchr() " Link "strrchr()"} @EndNode @Node "strcmp()" strcmp()-Compare strings Synopsis #include x = strcmp(a,b); int x; /* comparison result */ const char *a,*b; /* strings being compared */ Portability Returns The sign of the return value indicates the relative collating sequence of the strings, as indicated above. See Also @{" strcmpi() " Link "strcmpi()"} , @{" stricmp() " Link "stricmp()"} , @{" strncmp() " Link "strncmp()"} , @{" strnicmp() " Link "strnicmp()"} @EndNode @Node "strcoll()" strcoll()-Compare strings based on locale Synopsis #include res = strcoll(s1, s2); int res; /* result of comparison */ const char *s1,*s2; /* strings to compare */ Portability Returns This function returns a 0 if both strings are equal. If s1 is logically less than s2, the return value is less than 0. If s1 is logically greater than s2, the return value is greater than 0. See Also @{" setlocale() " Link "setlocale()"} @EndNode @Node "strcpy()" strcpy()-Copy one string to another Synopsis #include p = strcpy(to,from); char *p; /* same as destination pointer */ char *to; /* destination pointer */ const char *from; /* source pointer */ Portability Returns This function returns a pointer that is the same as the destination pointer. See Also @{" stccpy() " Link "stccpy()"} , @{" stpcpy() " Link "stpcpy()"} , @{" strncpy() " Link "strncpy()"} @EndNode @Node "strcspn()" strcspn()-Measure span of characters not in set Synopsis #include length = strcspn(s,b); size_t length; /* span length in bytes */ const char *s; /* points to string being scanned */ const char *b; /* points to character set string */ Portability Returns This function returns the number of bytes that are not in the specified character set. The scan always stops when the null terminator byte is reached. See Also @{" stcis() " Link "stcis()"} , @{" stcisn() " Link "stcisn()"} , @{" strspn() " Link "strspn()"} @EndNode @Node "strerror()" strerror()-Print text for a given error number Synopsis #include p = strerror(error); char *p; /* Pointer to text string */ int error; /* Error number */ Portability Returns This function returns a pointer to the text of the corresponding error message. If it could not find the error, it returns a null. The string is valid until the next call to strerror() and must not be modified by the caller. See Also @{" errno " Link "errno"} @EndNode @Node "strftime()" strftime()-Format time string Synopsis #include ret = strftime(s, max()size, format, timeptr); size_t ret; /* number of characters in */ /* formatted string */ char *s; /* string to place characters in */ size_t max()size; /* maximum string size */ const char *format; /* format instructions for string */ const struct tm *timeptr; /* broken-down time() information */ Portability Returns This function returns the number of characters placed into the string pointed to by s, not including the terminating null character. Otherwise, it returns a zero, and the contents of s are indeterminate. See Also @{" asctime() " Link "asctime()"} , @{" gmtime() " Link "gmtime()"} , @{" localtime() " Link "localtime()"} , @{" setlocale() " Link "setlocale()"} @EndNode @Node "strlen()" strlen()-Measure length of a string Synopsis #include length = strlen(s); size_t length; /* number of bytes in s (before null) */ const char *s; Portability Returns This function returns the number of bytes in string before the terminating null byte. See Also @{" stclen() " Link "stclen()"} @EndNode