The stdlib.h header file contains declarations for the following functions:
| abort() | abs()[1,3] | alloca()[1] | atexit() | atof() |
| atoi() | atol() | bsearch() | calloc() | cds()[1] |
| clearenv() | cs()[1] | csid() | div()[3] | exit() |
| fetch()[2] | fetchep()[2] | free() | getenv() | labs() |
| ldiv() | llabs() | lldiv() | __librel() | malloc() |
| mblen() | mbstowcs() | mbtowc() | __moservices() | qsort() |
| rand() | realloc() | release()[2] | rpmatch() | setenv() |
| srand() | strtod() | strtol() | strtoll() | strtoul() |
| strtoull() | system() | unatexit() | wcsid() | wcstombs() |
| wctomb() | strtod32()[4] | strtod64()[4] | strtod128()[4] |
_UNIX03_SOURCE
| unsetenv() |
[1] Built-in function.
[2] Not supported under C++ applications.
[3] Special Behavior for C++: For C++ applications, the functions abs() and div() are also overloaded for the type long.
[4] The __STDC_WANT_DEC_FP__ feature test macro is required to expose decimal floating-point functionality.
Two type definitions are added to stdlib.h for the Compare and Swap functions cs() and cds(). The structures defined are __cs_t and __cds_t.
The type size_t is declared in the header file. It is used for the type of the value returned by sizeof. The type wchar_t is declared and used for a wide character constant. For more information on the types size_t and wchar_t, see stddef.h.
The stdlib.h declares div_t and ldiv_t, which define the structure types that are returned by div() and ldiv().
If MB_CUR_MAX is set to 1, multibyte functions will behave as if all multibyte characters are one byte long; wide-character functions are not supported and full DBCS support is not provided. If MB_CUR_MAX is 4, all DBCS support provided by the library is enabled.