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mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-11-23 07:19:15 +00:00
emacs/lib/unsetenv.c
Paul Eggert 39c2fa3f4e Merge from gnulib and try to repair bad merge
This attempts to repair problems introduced by the bad merge
5491fd1098.  The easiest way for me
to fix the badly-merged gnulib files was to run
'admin/merge-gnulib', so I did that, which also imported the
following changes:
* build-aux/update-copyright, m4/gnulib.m4:
Update from gnulib, incorporating:
2015-01-15 time: port to MinGW32 3.21
2015-01-15 update-copyright: apply to self
2015-01-11 update-copyright: recognize groff's \(co marker
2015-01-27 22:24:47 -08:00

128 lines
2.8 KiB
C

/* Copyright (C) 1992, 1995-2002, 2005-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc
optimizes away the name == NULL test below. */
#define _GL_ARG_NONNULL(params)
#include <config.h>
/* Specification. */
#include <stdlib.h>
#include <errno.h>
#if !_LIBC
# define __set_errno(ev) ((errno) = (ev))
#endif
#include <string.h>
#include <unistd.h>
#if !_LIBC
# define __environ environ
#endif
#if _LIBC
/* This lock protects against simultaneous modifications of 'environ'. */
# 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
/* In the GNU C library we must keep the namespace clean. */
#ifdef _LIBC
# define unsetenv __unsetenv
#endif
#if _LIBC || !HAVE_UNSETENV
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] == '=')
{
/* Found it. Remove this pointer by moving later ones back. */
char **dp = ep;
do
dp[0] = dp[1];
while (*dp++);
/* Continue the loop in case NAME appears again. */
}
else
++ep;
UNLOCK;
return 0;
}
#ifdef _LIBC
# undef unsetenv
weak_alias (__unsetenv, unsetenv)
#endif
#else /* HAVE_UNSETENV */
# undef unsetenv
# if !HAVE_DECL_UNSETENV
# if VOID_UNSETENV
extern void unsetenv (const char *);
# else
extern int unsetenv (const char *);
# endif
# endif
/* Call the underlying unsetenv, in case there is hidden bookkeeping
that needs updating beyond just modifying environ. */
int
rpl_unsetenv (const char *name)
{
int result = 0;
if (!name || !*name || strchr (name, '='))
{
errno = EINVAL;
return -1;
}
while (getenv (name))
# if !VOID_UNSETENV
result =
# endif
unsetenv (name);
return result;
}
#endif /* HAVE_UNSETENV */