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emacs/lib/unsetenv.c
Paul Eggert 5745a7df2b Use putenv+unsetenv instead of modifying environ directly.
* admin/merge-gnulib (GNULIB_MODULES): Add putenv, unsetenv.
* lib/putenv.c, lib/unsetenv.c, m4/putenv.m4, m4/setenv.m4:
New files, copied automatically from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* src/alloc.c (xputenv): New function.
* src/dbusbind.c (Fdbus_init_bus):
* src/emacs.c (main):
* src/xterm.c (x_term_init):
Use xputenv instead of setenv or putenv, to detect memory exhaustion.
* src/editfns.c (initial_tz): Move static var decl up.
(tzvalbuf_in_environ): New static var.
(init_editfns):	Initialize these two static vars.
(Fencode_time): Don't assume arbitrary limit on EMACS_INT width.
Save old TZ value on stack, if it's small.
(Fencode_time, set_time_zone_rule): Don't modify 'environ' directly;
instead, use xputenv+unsetenv to set and restore TZ.
(environbuf): Remove static var.  All uses removed.
(Fset_time_zone_rule): Do not save TZ and environ;
no longer needed here.
(set_time_zone_rule_tz1, set_time_zone_rule_tz2) [LOCALTIME_CACHE]:
Move to inside set_time_zone_rule; they don't need file scope any more.
(set_time_zone_rule): Maintain the TZ=value string separately.
(syms_of_editfns): Don't initialize initial_tz;
init_editfns now does it.
* src/emacs.c (dump_tz) [HAVE_TZSET]: Now const.
* src/lisp.h (xputenv): New decl.

Fixes: debbugs:13070
2012-12-08 09:19:51 -08:00

127 lines
2.8 KiB
C

/* Copyright (C) 1992, 1995-2002, 2005-2012 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/>. */
#include <config.h>
/* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc
optimizes away the name == NULL test below. */
#define _GL_ARG_NONNULL(params)
/* 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 */