X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fputenv.c;h=d0573c69f144b8b21c272e69b961b29d4461ad8a;hb=03400ebfaa064922caf3767d6641d7e1cdc8cd1b;hp=a7060506c974631e48b2d7cc1cfada361c095782;hpb=5d08444ebcbd08cd195e1d9f52937a862c92efaa;p=gnulib.git

diff --git a/lib/putenv.c b/lib/putenv.c
index a7060506c..d0573c69f 100644
--- a/lib/putenv.c
+++ b/lib/putenv.c
@@ -1,63 +1,98 @@
-/* Copyright (C) 1991, 1994 Free Software Foundation, Inc.
+/* Copyright (C) 1991, 1994, 1997-1998, 2000, 2003-2008
+   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.
 
-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 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 2, or (at your option) 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.
 
-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/>.  */
 
-You should have received a copy of the GNU General Public License
-along with this program; if not, write to the Free Software Foundation,
-Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+#include <config.h>
 
-#include <errno.h>
+/* Specification.  */
+#include <stdlib.h>
 
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
+#include <stddef.h>
 
-/* Define-away any (possibly conflicting) prototype of putenv.
-   Many systems omit the `const' attribute on the argument.  */
-#define putenv _sys_putenv
+/* 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
 
-#if defined (__GNU_LIBRARY__) || defined (HAVE_STDLIB_H)
 #include <stdlib.h>
-#endif
-#if defined (__GNU_LIBRARY__) || defined (HAVE_STRING_H)
 #include <string.h>
-#endif
-#if defined (__GNU_LIBRARY__) || defined (HAVE_UNISTD_H)
 #include <unistd.h>
-#endif
-
-#undef putenv
-
-#if !defined (__GNU_LIBRARY__) && !defined (HAVE_STRCHR)
-#define strchr index
-#endif
-#if !defined (__GNU_LIBRARY__) && !defined (HAVE_MEMCPY)
-#define memcpy(d,s,n) bcopy ((s), (d), (n))
-#endif
 
 #if HAVE_GNU_LD
-#define environ __environ
+# define environ __environ
 #else
 extern char **environ;
 #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.  */
+/* Put STRING, which is of the form "NAME=VALUE", in the environment.
+   If STRING contains no `=', then remove STRING from the environment.  */
 int
-putenv (string)
-     const char *string;
+putenv (char *string)
 {
   const char *const name_end = strchr (string, '=');
   register size_t size;
@@ -66,18 +101,7 @@ putenv (string)
   if (name_end == NULL)
     {
       /* Remove the variable from the environment.  */
-      size = strlen (string);
-      for (ep = environ; *ep != NULL; ++ep)
-	if (!strncmp (*ep, string, size) && (*ep)[size] == '=')
-	  {
-	    while (ep[1] != NULL)
-	      {
-		ep[0] = ep[1];
-		++ep;
-	      }
-	    *ep = NULL;
-	    return 0;
-	  }
+      return _unsetenv (string);
     }
 
   size = 0;
@@ -98,13 +122,12 @@ putenv (string)
 		     size * sizeof (char *));
       new_environ[size] = (char *) string;
       new_environ[size + 1] = NULL;
-      if (last_environ != NULL)
-	free ((void *) last_environ);
+      free (last_environ);
       last_environ = new_environ;
       environ = new_environ;
     }
   else
-    *ep = (char *) string;
+    *ep = string;
 
   return 0;
 }