stdlib.h - standard library definitions

#include <stdlib.h>

Some of the functionality described on this reference page extends the ISO C standard. Applications shall define the appropriate feature test macro (see the System Interfaces volume of IEEE Std 1003.1-2001, Section 2.2, The Compilation Environment) to enable the visibility of these symbols in this header.

The <stdlib.h> header shall define the following macros:

EXIT_FAILURE

Unsuccessful termination for exit(); evaluates to a non-zero value.

EXIT_SUCCESS

Successful termination for exit(); evaluates to 0.

NULL

Null pointer.

{RAND_MAX}

Maximum value returned by rand(); at least 32767.

{MB_CUR_MAX}

Integer expression whose value is the maximum number of bytes in a character specified by the current locale.

The following data types shall be defined through typedef:

div_t

Structure type returned by the div() function.

ldiv_t

Structure type returned by the ldiv() function.

lldiv_t

Structure type returned by the lldiv() function.

size_t

As described in <stddef.h> .

wchar_t

As described in <stddef.h> .

In addition, the following symbolic names and macros shall be defined as in <sys/wait.h> , for use in decoding the return value from system():

WNOHANG

WUNTRACED

WEXITSTATUS

WIFEXITED

WIFSIGNALED

WIFSTOPPED

WSTOPSIG

WTERMSIG

The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.

void _Exit(int);

long a64l(const char *);

void abort(void); int abs(int); int atexit(void (*)(void)); double atof(const char *); int atoi(const char *); long atol(const char *); long long atoll(const char *); void *bsearch(const void *, const void *, size_t, size_t, int (*)(const void *, const void *)); void *calloc(size_t, size_t); div_t div(int, int);

double drand48(void); char *ecvt(double, int, int *restrict, int *restrict); (LEGACY ) double erand48(unsigned short[3]);

void exit(int);

char *fcvt(double, int, int *restrict, int *restrict); (LEGACY )

void free(void *);

char *gcvt(double, int, char *); (LEGACY )

char *getenv(const char *);

int getsubopt(char **, char *const *, char **); int grantpt(int); char *initstate(unsigned, char *, size_t); long jrand48(unsigned short[3]); char *l64a(long);

long labs(long);

void lcong48(unsigned short[7]);

ldiv_t ldiv(long, long); long long llabs(long long); lldiv_t lldiv(long long, long long);

long lrand48(void);

void *malloc(size_t); int mblen(const char *, size_t); size_t mbstowcs(wchar_t *restrict, const char *restrict, size_t); int mbtowc(wchar_t *restrict, const char *restrict, size_t);

char *mktemp(char *); (LEGACY ) int mkstemp(char *); long mrand48(void); long nrand48(unsigned short[3]);

int posix_memalign(void **, size_t, size_t);

int posix_openpt(int); char *ptsname(int); int putenv(char *);

void qsort(void *, size_t, size_t, int (*)(const void *, const void *)); int rand(void);

int rand_r(unsigned *);

long random(void);

void *realloc(void *, size_t);

char *realpath(const char *restrict, char *restrict); unsigned short seed48(unsigned short[3]);

int setenv(const char *, const char *, int);

void setkey(const char *); char *setstate(const char *);

void srand(unsigned);

void srand48(long); void srandom(unsigned);

double strtod(const char *restrict, char **restrict); float strtof(const char *restrict, char **restrict); long strtol(const char *restrict, char **restrict, int); long double strtold(const char *restrict, char **restrict); long long strtoll(const char *restrict, char **restrict, int); unsigned long strtoul(const char *restrict, char **restrict, int); unsigned long long strtoull(const char *restrict, char **restrict, int); int system(const char *);

int unlockpt(int);

int unsetenv(const char *);

size_t wcstombs(char *restrict, const wchar_t *restrict, size_t); int wctomb(char *, wchar_t);

Inclusion of the <stdlib.h> header may also make visible all symbols from <stddef.h>, <limits.h>, <math.h>, and <sys/wait.h>.

The following sections are informative.

None.

None.

None.

<limits.h> , <math.h> , <stddef.h> , <sys/types.h> , <sys/wait.h> , the System Interfaces volume of IEEE Std 1003.1-2001, _Exit(), a64l(), abort(), abs(), atexit(), atof(), atoi(), atol(), atoll(), bsearch(), calloc(), div(), drand48(), erand48(), exit(), free(), getenv(), getsubopt(), grantpt(), initstate(), jrand48(), l64a(), labs(), lcong48(), ldiv(), llabs(), lldiv(), lrand48(), malloc(), mblen(), mbstowcs(), mbtowc(), mkstemp(), mrand48(), nrand48(), posix_memalign(), ptsname(), putenv(), qsort(), rand(), realloc(), realpath(), setstate(), srand(), srand48(), srandom(), strtod(), strtof(), strtol(), strtold(), strtoll(), strtoul(), strtoull(), unlockpt(), wcstombs(), wctomb()

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .