#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <errno.h>
#if !_LIBC
# if !defined errno && !defined HAVE_ERRNO_DECL
extern int errno;
# endif
# define __set_errno(ev) ((errno) = (ev))
#endif
#include <stdlib.h>
#include <string.h>
#if _LIBC || HAVE_UNISTD_H
# include <unistd.h>
#endif
#if !_LIBC
# define __environ environ
# ifndef HAVE_ENVIRON_DECL
extern char **environ;
# endif
#endif
#if _LIBC
# include <bits/libc-lock.h>
__libc_lock_define_initialized (static, envlock)
# define LOCK __libc_lock_lock (envlock)
# define UNLOCK __libc_lock_unlock (envlock)
#else
# define LOCK
# define UNLOCK
#endif
#ifdef _LIBC
# define unsetenv __unsetenv
#endif
int
unsetenv (const char *name)
{
size_t len;
char **ep;
if (name == NULL || *name == '\0' || strchr (name, '=') != NULL)
{
__set_errno (EINVAL);
return -1;
}
len = strlen (name);
LOCK;
ep = __environ;
while (*ep != NULL)
if (!strncmp (*ep, name, len) && (*ep)[len] == '=')
{
char **dp = ep;
do
dp[0] = dp[1];
while (*dp++);
}
else
++ep;
UNLOCK;
return 0;
}
#ifdef _LIBC
# undef unsetenv
weak_alias (__unsetenv, unsetenv)
#endif