stdlib.h File Reference

<stdlib.h>: POSIX extensions to the C standard library More...

#include <stddef.h>

Include dependency graph for posix_stdlib.h:

Go to the source code of this file.

Functions
int	getenv_r (const char *name, char *buf, size_t len)
	Get an environment variable into a caller-supplied buffer (BSD extension).
int	getsubopt (char **optionp, char *const *keylistp, char **valuep)
	Parse sub-options from a command-line argument string.
int	putenv (char *string)
	Add or change an environment variable (XSI extension).
int	setenv (const char *envname, const char *envval, int overwrite)
	Set the value of an environment variable.
int	unsetenv (const char *name)
	Remove an environment variable.
int	rand_r (unsigned int *seed)
	Generate a pseudo-random number (reentrant).
void	qsort_r (void *base, size_t nmemb, size_t size, int(*compar)(const void *a, const void *b, void *arg), void *arg)
	Sort an array with a comparison function that takes a context argument.

Detailed Description

<stdlib.h>: POSIX extensions to the C standard library

Provides POSIX and XSI extensions to the standard <stdlib.h> interface, including environment variable manipulation and sub-option parsing.

See also

POSIX.1-2017 <stdlib.h>

Definition in file stdlib.h.

Function Documentation

getenv_r()

int getenv_r	(	const char *	name,
		char *	buf,
		size_t	len
	)

Get an environment variable into a caller-supplied buffer (BSD extension).

Parameters

name	Name of the environment variable.
buf	Buffer to write the value into.
len	Size of buf.

Returns

0 on success, or a positive error number on failure (ENOENT if not set, ERANGE if buf is too small).