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mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-12-28 10:56:36 +00:00
emacs/lib/putenv.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

135 lines
3.2 KiB
C

/* Copyright (C) 1991, 1994, 1997-1998, 2000, 2003-2012 Free Software
Foundation, Inc.
NOTE: The canonical source of this file is maintained with the GNU C
Library. Bugs can be reported to bug-glibc@prep.ai.mit.edu.
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 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>
/* Specification. */
#include <stdlib.h>
#include <stddef.h>
/* Include errno.h *after* sys/types.h to work around header problems
on AIX 3.2.5. */
#include <errno.h>
#ifndef __set_errno
# define __set_errno(ev) ((errno) = (ev))
#endif
#include <string.h>
#include <unistd.h>
#if _LIBC
# if HAVE_GNU_LD
# define environ __environ
# else
extern char **environ;
# endif
#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
static 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;
}
/* Put STRING, which is of the form "NAME=VALUE", in the environment.
If STRING contains no '=', then remove STRING from the environment. */
int
putenv (char *string)
{
const char *const name_end = strchr (string, '=');
register size_t size;
register char **ep;
if (name_end == NULL)
{
/* Remove the variable from the environment. */
return _unsetenv (string);
}
size = 0;
for (ep = environ; *ep != NULL; ++ep)
if (!strncmp (*ep, string, name_end - string) &&
(*ep)[name_end - string] == '=')
break;
else
++size;
if (*ep == NULL)
{
static char **last_environ = NULL;
char **new_environ = (char **) malloc ((size + 2) * sizeof (char *));
if (new_environ == NULL)
return -1;
(void) memcpy ((void *) new_environ, (void *) environ,
size * sizeof (char *));
new_environ[size] = (char *) string;
new_environ[size + 1] = NULL;
free (last_environ);
last_environ = new_environ;
environ = new_environ;
}
else
*ep = string;
return 0;
}