lib/libc/stdlib/putenv.c

   1 /*      $NetBSD: putenv.c,v 1.19 2010/11/14 18:11:43 tron Exp $ */
   2
   3 /*-
   4  * Copyright (c) 1988, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char sccsid[] = "@(#)putenv.c    8.2 (Berkeley) 3/27/94";
  36 #else
  37 __RCSID("$NetBSD: putenv.c,v 1.19 2010/11/14 18:11:43 tron Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include "namespace.h"
  42
  43 #include <assert.h>
  44 #include <errno.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47
  48 #include "env.h"
  49 #include "reentrant.h"
  50 #include "local.h"
  51
  52 #ifdef __weak_alias
  53 __weak_alias(putenv,_putenv)
  54 #endif
  55
  56 int
  57 putenv(char *str)
  58 {
  59         size_t l_name;
  60         int rv;
  61
  62         _DIAGASSERT(str != NULL);
  63
  64         l_name = __envvarnamelen(str, true);
  65         if (l_name == 0) {
  66                 errno = EINVAL;
  67                 return -1;
  68         }
  69
  70         rv = -1;
  71         if (__writelockenv()) {
  72                 ssize_t offset;
  73
  74                 offset = __getenvslot(str, l_name, true);
  75                 if (offset != -1) {
  76                         if (environ[offset] != NULL)
  77                                 __freeenvvar(environ[offset]);
  78                         environ[offset] = str;
  79
  80                         rv = 0;
  81                 }
  82
  83                 (void)__unlockenv();
  84         }
  85
  86         return rv;
  87 }