putenv.c revision 1.16 
1/*	$NetBSD: putenv.c,v 1.16 2010/10/05 02:23:38 enami 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
35static char sccsid[] = "@(#)putenv.c	8.2 (Berkeley) 3/27/94";
36#else
37__RCSID("$NetBSD: putenv.c,v 1.16 2010/10/05 02:23:38 enami 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#include "reentrant.h"
48#include "local.h"
49
50#ifdef __weak_alias
51__weak_alias(putenv,_putenv)
52#endif
53
54int
55putenv(char *str)
56{
57	char *p;
58	int offset;
59
60	_DIAGASSERT(str != NULL);
61
62	if (strchr(str, '=') == NULL)
63		return -1;
64
65	if (rwlock_wrlock(&__environ_lock) != 0)
66		return -1;
67
68	p = __findenv(str, &offset);
69
70	if (__allocenv(offset) == -1)
71		goto bad;
72
73	if (p != NULL && environ[offset] == __environ_malloced[offset]) {
74		free(__environ_malloced[offset]);
75		__environ_malloced[offset] = NULL;
76	}
77
78	environ[offset] = str;
79	rwlock_unlock(&__environ_lock);
80	return 0;
81bad:
82	rwlock_unlock(&__environ_lock);
83	return -1;
84}
85