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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /sysdeps/generic/putenv.c
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initial import
Diffstat (limited to 'sysdeps/generic/putenv.c')
-rw-r--r--sysdeps/generic/putenv.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/sysdeps/generic/putenv.c b/sysdeps/generic/putenv.c
new file mode 100644
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+++ b/sysdeps/generic/putenv.c
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+/* Copyright (C) 1991, 1994 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., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <errno.h>
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#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
+
+#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
+
+#ifndef	HAVE_GNU_LD
+#define	__environ	environ
+#endif
+
+
+/* Put STRING, which is of the form "NAME=VALUE", in the environment.  */
+int
+putenv (string)
+     const char *string;
+{
+  const char *const name_end = strchr (string, '=');
+  register size_t size;
+  register char **ep;
+
+  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;
+	  }
+    }
+
+  size = 0;
+  for (ep = __environ; *ep != NULL; ++ep)
+    if (!strncmp (*ep, string, name_end - string) &&
+	(*ep)[name_end - string] == '=')
+      break;
+    else
+      ++size;
+
+  if (*ep == NULL)
+    {
+      static char **last_environ = NULL;
+      char **new_environ = (char **) malloc ((size + 2) * sizeof (char *));
+      if (new_environ == NULL)
+	return -1;
+      (void) memcpy ((void *) new_environ, (void *) __environ,
+		     size * sizeof (char *));
+      new_environ[size] = (char *) string;
+      new_environ[size + 1] = NULL;
+      if (last_environ != NULL)
+	free ((void *) last_environ);
+      last_environ = new_environ;
+      __environ = new_environ;
+    }
+  else
+    *ep = (char *) string;
+
+  return 0;
+}