#include <stdlib.h>
The <stdlib.h> header shall define the following macros which shall expand to integer constant expressions:
The <stdlib.h> header shall define the following macro which shall expand to a positive integer expression with type size_t:
In the POSIX locale the value of {MB_CUR_MAX} shall be 1.
The <stdlib.h> header shall define NULL as described in <stddef.h>.
The <stdlib.h> header shall define the following data types through typedef:
In addition, the <stdlib.h> header shall define the following symbolic constants and macros as described in <sys/wait.h>:
WEXITSTATUS WIFEXITED WIFSIGNALED WIFSTOPPED WNOHANG WSTOPSIG WTERMSIG WUNTRACED
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);
double erand48(unsigned short [3]);
void exit(int);
void free(void *);
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 *mkdtemp(char *);
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(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.
The System Interfaces volume of POSIX.1-2017, Section 2.2, The Compilation Environment, _Exit(), a64l(), abort(), abs(), atexit(), atof(), atoi(), atol(), bsearch(), calloc(), div(), drand48(), exit(), free(), getenv(), getsubopt(), grantpt(), initstate(), labs(), ldiv(), malloc(), mblen(), mbstowcs(), mbtowc(), mkdtemp(), posix_memalign(), posix_openpt(), ptsname(), putenv(), qsort(), rand(), realloc(), realpath(), setenv(), setkey(), strtod(), strtol(), strtoul(), system(), unlockpt(), unsetenv(), wcstombs(), wctomb()
Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .