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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>
- /* Experimentally off - libc_hidden_proto(memcpy) */
- /* Experimentally off - libc_hidden_proto(strchr) */
- /* Experimentally off - libc_hidden_proto(strlen) */
- /* Experimentally off - libc_hidden_proto(strncmp) */
- /* Experimentally off - libc_hidden_proto(strndup) */
- /* libc_hidden_proto(unsetenv) */
- #include <bits/uClibc_mutex.h>
- __UCLIBC_MUTEX_STATIC(mylock, PTHREAD_MUTEX_INITIALIZER);
- /* 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,
- char *combined, int replace) attribute_hidden;
- int __add_to_environ(const char *name, const char *value,
- char *combined, int replace)
- {
- register char **ep;
- register size_t size;
- /* name may come from putenv() and thus may contain "=VAL" part */
- const size_t namelen = strchrnul(name, '=') - name;
- const size_t vallen = value != NULL ? strlen(value) + 1 : 0;
- int rv = -1;
- __UCLIBC_MUTEX_LOCK(mylock);
- /* 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;
- ++size;
- }
- }
- if (ep == NULL || *ep == NULL) {
- /* Not found, add at the end */
- char **new_environ;
- /* We allocated this space; we can extend it. */
- new_environ = realloc(last_environ, (size + 2) * sizeof(char *));
- if (new_environ == NULL) {
- __set_errno(ENOMEM);
- goto DONE;
- }
- if (__environ != last_environ) {
- memcpy(new_environ, __environ, size * sizeof(char *));
- }
- last_environ = __environ = new_environ;
- if (combined != NULL) {
- /* If the whole "VAR=VAL" is given, add it. */
- /* We must not add the string to the search tree
- * since it belongs to the user.
- * [glibc comment, uclibc doesnt track ptrs] */
- new_environ[size] = combined;
- } else {
- /* Build new "VAR=VAL" string. */
- new_environ[size] = malloc(namelen + 1 + vallen);
- if (new_environ[size] == NULL) {
- __set_errno(ENOMEM);
- goto DONE;
- }
- memcpy(new_environ[size], name, namelen);
- new_environ[size][namelen] = '=';
- memcpy(&new_environ[size][namelen + 1], value, vallen);
- }
- new_environ[size + 1] = NULL;
- } else if (replace) {
- /* Build the name if needed. */
- if (combined == NULL) {
- combined = malloc(namelen + 1 + vallen);
- if (combined == NULL) {
- __set_errno(ENOMEM);
- goto DONE;
- }
- memcpy(combined, name, namelen);
- combined[namelen] = '=';
- memcpy(&combined[namelen + 1], value, vallen);
- }
- *ep = combined;
- }
- rv = 0;
- DONE:
- __UCLIBC_MUTEX_UNLOCK(mylock);
- return rv;
- }
- /* libc_hidden_proto(setenv) */
- int setenv(const char *name, const char *value, int replace)
- {
- return __add_to_environ(name, value, NULL, replace);
- }
- libc_hidden_def(setenv)
- /* libc_hidden_proto(unsetenv) */
- int unsetenv(const char *name)
- {
- const char *eq;
- size_t len;
- char **ep;
- if (name == NULL || *name == '\0'
- || *(eq = strchrnul(name, '=')) == '='
- ) {
- __set_errno(EINVAL);
- return -1;
- }
- len = eq - name; /* avoiding strlen this way */
- __UCLIBC_MUTEX_LOCK(mylock);
- ep = __environ;
- /* NB: clearenv(); unsetenv("foo"); should not segfault */
- if (ep) 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;
- }
- }
- __UCLIBC_MUTEX_UNLOCK(mylock);
- return 0;
- }
- libc_hidden_def(unsetenv)
- /* 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)
- {
- __UCLIBC_MUTEX_LOCK(mylock);
- /* If we allocated this environment we can free it.
- * If we did not allocate this environment, it's NULL already
- * and is safe to free(). */
- free(last_environ);
- last_environ = NULL;
- /* Clear the environment pointer removes the whole environment. */
- __environ = NULL;
- __UCLIBC_MUTEX_UNLOCK(mylock);
- return 0;
- }
- /* Put STRING, which is of the form "NAME=VALUE", in the environment. */
- int putenv(char *string)
- {
- if (strchr(string, '=') != NULL) {
- return __add_to_environ(string, NULL, string, 1);
- }
- return unsetenv(string);
- }
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