The
<stdlib.h> header defines the following types and macros:
1.
NULL - an implementation-defined null pointer constant;
2.
size_t and
wchar_t - integer types described in
stddef(3);
3.
div_t,
ldiv_t, and
lldiv_t - structures that are returned by the
div(3),
ldiv(3), and
lldiv(3) functions, respectively;
4.
RAND_MAX - a macro which expands to an integer constant that is the maximum value returned by the
rand(3) function;
5.
MB_CUR_MAX - an integer expression of type size_t whose value is the maximum number of bytes in a character specified by the current locale; and
6.
EXIT_SUCCESS and
EXIT_FAILURE - macros which expand to integer constants suitable for use as an argument to the
exit(3) function.
The
<stdlib.h> header also prototypes several important functions such as
abort(3),
atoi(3),
bsearch(3),
free(3),
malloc(3), and
strtol(3).