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-rw-r--r--libc/stdlib/setenv.c184
1 files changed, 126 insertions, 58 deletions
diff --git a/libc/stdlib/setenv.c b/libc/stdlib/setenv.c
index f7d597139..b17280562 100644
--- a/libc/stdlib/setenv.c
+++ b/libc/stdlib/setenv.c
@@ -1,76 +1,144 @@
-/* Copyright (C) 1995,1996 Robert de Bath <rdebath@cix.compulink.co.uk>
- * This file is part of the Linux-8086 C library and is distributed
- * under the GNU Library General Public License.
- */
-#include <string.h>
-#include <stdlib.h>
-#include <malloc.h>
+/* Copyright (C) 1992, 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
-extern char **environ;
+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.
-#define ADD_NUM 4
+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.
-int setenv(var, value, overwrite)
-const char *var;
-const char *value;
-int overwrite;
-{
- static char **mall_env = 0;
- static int extras = 0;
- char **p, **d;
- char *t;
- int len;
+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., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
- len = strlen(var);
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
- if (!environ) {
- environ = (char **) malloc(ADD_NUM * sizeof(char *));
- memset(environ, 0, sizeof(char *) * ADD_NUM);
+#if !defined(HAVE_GNU_LD) && !defined (__ELF__)
+#define __environ environ
+#endif
- extras = ADD_NUM;
- }
+#if defined(_REENTRENT) || defined(_THREAD_SAFE)
+# include <pthread.h>
- for (p = environ; *p; p++) {
- if (memcmp(var, *p, len) == 0 && (*p)[len] == '=') {
- if (!overwrite)
- return -1;
- /* Overwrite stuff */
- while ((p[0] = p[1]))
- p++;
- extras++;
- break;
- }
- }
+/* We need to initialize the mutex. For this we use a method provided
+ by pthread function 'pthread_once'. For this we need a once block. */
+static pthread_once__t _once_block = pthread_once_init;
+
+/* This is the mutex which protects the global environment of simultaneous
+ modifications. */
+static pthread_mutex_t _setenv_mutex;
+
+static void
+DEFUN_VOID(_init_setenv_mutex)
+{
+ pthread_mutex_init(&_setenv_mutex, pthread_mutexattr_default);
+}
- if (extras <= 0) { /* Need more space */
- d = malloc((p - environ + 1 + ADD_NUM) * sizeof(char *));
+# define LOCK() \
+ do { pthread_once(&_once_block, _init_setenv_mutex);
+ pthread_mutex_lock(&_setenv_mutex); } while (0)
+# define UNLOCK() pthread_mutex_unlock(&_setenv_mutex)
- if (d == 0)
- return -1;
+#else /* !_REENTRENT && !_THREAD_SAFE */
- memcpy((void *) d, (void *) environ,
+# define LOCK()
+# define UNLOCK()
- (p - environ + 1) * sizeof(char *));
- p = d + (p - environ);
- extras = ADD_NUM;
+#endif /* _REENTRENT || _THREAD_SAFE */
- if (mall_env)
- free(mall_env);
- environ = d;
- mall_env = d;
+int setenv(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);
+ int result = 0;
+
+ LOCK();
+
+ size = 0;
+ for (ep = __environ; *ep != NULL; ++ep)
+ if (!memcmp (*ep, name, namelen) && (*ep)[namelen] == '=')
+ break;
+ else
+ ++size;
+
+ if (*ep == NULL)
+ {
+ static char **last_environ = NULL;
+ char **new_environ = (char **) malloc((size + 2) * sizeof(char *));
+ if (new_environ == NULL)
+ {
+ result = -1;
+ goto do_return;
+ }
+ (void) memcpy((__ptr_t) new_environ, (__ptr_t) __environ, size * sizeof(char *));
+
+ new_environ[size] = malloc (namelen + 1 + vallen + 1);
+ if (new_environ[size] == NULL)
+ {
+ free (new_environ);
+ errno = ENOMEM;
+ result = -1;
+ goto do_return;
+ }
+ memcpy (new_environ[size], name, namelen);
+ new_environ[size][namelen] = '=';
+ memcpy (&new_environ[size][namelen + 1], value, vallen + 1);
+
+ new_environ[size + 1] = NULL;
+
+ if (last_environ != NULL)
+ free ((__ptr_t) last_environ);
+ last_environ = new_environ;
+ __environ = new_environ;
+ }
+ else if (replace)
+ {
+ size_t len = strlen (*ep);
+ if (len < namelen + 1 + vallen)
+ {
+ char *new = malloc (namelen + 1 + vallen + 1);
+ if (new == NULL)
+ {
+ result = -1;
+ goto do_return;
+ }
+ *ep = new;
+ memcpy (*ep, name, namelen);
+ (*ep)[namelen] = '=';
}
+ memcpy (&(*ep)[namelen + 1], value, vallen + 1);
+ }
- t = malloc(len + 1 + strlen(value) + 1);
- if (!t)
- return -1;
+do_return:
+ UNLOCK();
+ return result;
+}
+
+
+void unsetenv(const char *name)
+{
+ register char **ep;
+ register char **dp;
+ const size_t namelen = strlen (name);
- strcpy(t, var);
- strcat(t, "=");
- strcat(t, value);
+ LOCK();
- *p++ = (char *) t;
- *p = '\0';
- extras--;
+ for (dp = ep = __environ; *ep != NULL; ++ep)
+ if (memcmp (*ep, name, namelen) || (*ep)[namelen] != '=')
+ {
+ *dp = *ep;
+ ++dp;
+ }
+ *dp = NULL;
- return 0;
+ UNLOCK();
}