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/* Copyright (C) 1992,95,96,97,98,99,2000,2001 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.
modified for uClibc by Erik Andersen <andersen@codepoet.org>
*/
#include <features.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef __UCLIBC_HAS_THREADS__
/* 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
/* If this variable is not a null pointer we allocated the current
environment. */
static char **last_environ;
/* This function is used by `setenv' and `putenv'. The difference between
the two functions is that for the former must create a new string which
is then placed in the environment, while the argument of `putenv'
must be used directly. This is all complicated by the fact that we try
to reuse values once generated for a `setenv' call since we can never
free the strings. */
int __add_to_environ (const char *name, const char *value,
const char *combined, int replace)
{
register char **ep;
register size_t size;
const size_t namelen = strlen (name);
const size_t vallen = value != NULL ? strlen (value) + 1 : 0;
LOCK;
/* We have to get the pointer now that we have the lock and not earlier
since another thread might have created a new environment. */
ep = __environ;
size = 0;
if (ep != NULL) {
for (; *ep != NULL; ++ep) {
if (!strncmp (*ep, name, namelen) && (*ep)[namelen] == '=')
break;
else
++size;
}
}
if (ep == NULL || *ep == NULL) {
char **new_environ;
/* We allocated this space; we can extend it. */
new_environ = (char **) realloc (last_environ,
(size + 2) * sizeof (char *));
if (new_environ == NULL) {
UNLOCK;
return -1;
}
/* If the whole entry is given add it. */
if (combined != NULL) {
/* We must not add the string to the search tree since it belongs
to the user. */
new_environ[size] = (char *) combined;
} else {
/* See whether the value is already known. */
new_environ[size] = (char *) malloc (namelen + 1 + vallen);
if (new_environ[size] == NULL) {
__set_errno (ENOMEM);
UNLOCK;
return -1;
}
memcpy (new_environ[size], name, namelen);
new_environ[size][namelen] = '=';
memcpy (&new_environ[size][namelen + 1], value, vallen);
}
if (__environ != last_environ) {
memcpy ((char *) new_environ, (char *) __environ,
size * sizeof (char *));
}
new_environ[size + 1] = NULL;
last_environ = __environ = new_environ;
} else if (replace) {
char *np;
/* Use the user string if given. */
if (combined != NULL) {
np = (char *) combined;
} else {
np = malloc (namelen + 1 + vallen);
if (np == NULL) {
UNLOCK;
return -1;
}
memcpy (np, name, namelen);
np[namelen] = '=';
memcpy (&np[namelen + 1], value, vallen);
}
*ep = np;
}
UNLOCK;
return 0;
}
int setenv (const char *name, const char *value, int replace)
{
return __add_to_environ (name, value, NULL, replace);
}
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;
}
/* 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 (void)
{
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;
}
/* Put STRING, which is of the form "NAME=VALUE", in the environment. */
int putenv (char *string)
{
int result;
const char *const name_end = strchr (string, '=');
if (name_end != NULL) {
char *name = strndup(string, name_end - string);
result = __add_to_environ (name, NULL, string, 1);
free(name);
return(result);
}
__unsetenv (string);
return 0;
}
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