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/* Copyright (C) 1992, 1995, 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <errno.h>
#if _LIBC || HAVE_STDLIB_H
# include <stdlib.h>
#endif
#if _LIBC || HAVE_STRING_H
# include <string.h>
#endif
#if _LIBC || HAVE_UNISTD_H
# include <unistd.h>
#endif
#if _LIBC - 0 == 0
# define __environ environ
#endif
#if _LIBC - 0
/* This lock protects against simultaneous modifications of `environ'. */
# include <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
/* If this variable is not a null pointer we allocated the current
environment. */
static char **last_environ;
int
setenv (name, value, replace)
const char *name;
const char *value;
int replace;
{
register char **ep;
register size_t size;
const size_t namelen = strlen (name);
const size_t vallen = strlen (value) + 1;
LOCK;
size = 0;
if (__environ != NULL)
for (ep = __environ; *ep != NULL; ++ep)
if (!strncmp (*ep, name, namelen) && (*ep)[namelen] == '=')
break;
else
++size;
if (__environ == NULL || *ep == NULL)
{
char **new_environ;
if (__environ == last_environ && __environ != NULL)
/* We allocated this space; we can extend it. */
new_environ = (char **) realloc (last_environ,
(size + 2) * sizeof (char *));
else
new_environ = (char **) malloc ((size + 2) * sizeof (char *));
if (new_environ == NULL)
{
UNLOCK;
return -1;
}
new_environ[size] = malloc (namelen + 1 + vallen);
if (new_environ[size] == NULL)
{
free ((char *) new_environ);
__set_errno (ENOMEM);
UNLOCK;
return -1;
}
if (__environ != last_environ)
memcpy ((char *) new_environ, (char *) __environ,
size * sizeof (char *));
memcpy (new_environ[size], name, namelen);
new_environ[size][namelen] = '=';
memcpy (&new_environ[size][namelen + 1], value, vallen);
new_environ[size + 1] = NULL;
last_environ = __environ = new_environ;
}
else if (replace)
{
size_t len = strlen (*ep);
if (len + 1 < namelen + 1 + vallen)
{
/* The existing string is too short; malloc a new one. */
char *new = malloc (namelen + 1 + vallen);
if (new == NULL)
{
UNLOCK;
return -1;
}
*ep = new;
}
memcpy (*ep, name, namelen);
(*ep)[namelen] = '=';
memcpy (&(*ep)[namelen + 1], value, vallen);
}
UNLOCK;
return 0;
}
void
unsetenv (name)
const char *name;
{
const size_t len = strlen (name);
char **ep;
LOCK;
for (ep = __environ; *ep; ++ep)
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. */
}
UNLOCK;
}
/* The `clearenv' was planned to be added to POSIX.1 but probably
never made it. Nevertheless the POSIX.9 standard (POSIX bindings
for Fortran 77) requires this function. */
int
clearenv ()
{
LOCK;
if (__environ == last_environ && __environ != NULL)
{
/* We allocated this environment so we can free it. */
free (__environ);
last_environ = NULL;
}
/* Clear the environment pointer removes the whole environment. */
__environ = NULL;
UNLOCK;
return 0;
}
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