stdlib.h(0p) — Linux manual page


stdlib.h(0P)            POSIX Programmer's Manual           stdlib.h(0P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.

NAME         top

       stdlib.h — standard library definitions

SYNOPSIS         top

       #include <stdlib.h>

DESCRIPTION         top

       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 POSIX.1‐2017, 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 which
       shall expand to integer constant expressions:

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

                   Successful termination for exit(); evaluates to 0.

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

       The <stdlib.h> header shall define the following macro which
       shall expand to a positive integer expression with type size_t:

                   Maximum number of bytes in a character specified by
                   the current locale (category LC_CTYPE).

       In the POSIX locale the value of {MB_CUR_MAX} shall be 1.

       The <stdlib.h> header shall define NULL as described in

       The <stdlib.h> header shall define the following data types
       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 <stdlib.h> header shall define the following
       symbolic constants and macros as described in <sys/wait.h>:


       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.



RATIONALE         top




SEE ALSO         top

       limits.h(0p), math.h(0p), stddef.h(0p), sys_types.h(0p),

       The System Interfaces volume of POSIX.1‐2017, Section 2.2, The
       Compilation Environment, _Exit(3p), a64l(3p), abort(3p), abs(3p),
       atexit(3p), atof(3p), atoi(3p), atol(3p), bsearch(3p),
       calloc(3p), div(3p), drand48(3p), exit(3p), free(3p), getenv(3p),
       getsubopt(3p), grantpt(3p), initstate(3p), labs(3p), ldiv(3p),
       malloc(3p), mblen(3p), mbstowcs(3p), mbtowc(3p), mkdtemp(3p),
       posix_memalign(3p), posix_openpt(3p), ptsname(3p), putenv(3p),
       qsort(3p), rand(3p), realloc(3p), realpath(3p), setenv(3p),
       setkey(3p), strtod(3p), strtol(3p), strtoul(3p), system(3p),
       unlockpt(3p), unsetenv(3p), wcstombs(3p), wctomb(3p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 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 .

       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 .

IEEE/The Open Group               2017                      stdlib.h(0P)

Pages that refer to this page: float.h(0p)wchar.h(0p)wctype.h(0p)a64l(3p)abort(3p)abs(3p)atexit(3p)atof(3p)atoi(3p)atol(3p)bsearch(3p)calloc(3p)div(3p)drand48(3p)exit(3p)_Exit(3p)free(3p)getenv(3p)getsubopt(3p)grantpt(3p)initstate(3p)labs(3p)ldiv(3p)malloc(3p)mblen(3p)mbstowcs(3p)mbtowc(3p)mkdtemp(3p)posix_memalign(3p)posix_openpt(3p)ptsname(3p)putenv(3p)qsort(3p)rand(3p)realloc(3p)realpath(3p)setenv(3p)setkey(3p)strtod(3p)strtol(3p)strtoul(3p)system(3p)unlockpt(3p)unsetenv(3p)wcstombs(3p)wctomb(3p)