compat_unsetenv.c revision 1.1 
1/*	$NetBSD: compat_unsetenv.c,v 1.1 2005/09/13 01:44:09 christos Exp $	*/
2
3/*
4 * Copyright (c) 1987, 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[] = "from: @(#)setenv.c	8.1 (Berkeley) 6/4/93";
36#else
37__RCSID("$NetBSD: compat_unsetenv.c,v 1.1 2005/09/13 01:44:09 christos Exp $");
38#endif
39#endif /* LIBC_SCCS and not lint */
40
41#define __LIBC12_SOURCE__
42#include "namespace.h"
43
44#include <assert.h>
45#include <errno.h>
46#include <stdlib.h>
47#include <compat/include/stdlib.h>
48#include <string.h>
49#include "local.h"
50#include "reentrant.h"
51
52#ifdef __weak_alias
53__weak_alias(unsetenv,_unsetenv)
54#endif
55
56#ifdef _REENTRANT
57extern rwlock_t __environ_lock;
58#endif
59
60__warn_references(unsetenv,
61    "warning: reference to compatibility unsetenv();"
62    " include <stdlib.h> for correct reference")
63
64extern char **environ;
65
66/*
67 * unsetenv(name) --
68 *	Delete environmental variable "name".
69 */
70void
71unsetenv(const char *name)
72{
73	char **p;
74	int offset;
75
76	_DIAGASSERT(name != NULL);
77
78	rwlock_wrlock(&__environ_lock);
79	while (__findenv(name, &offset))	/* if set multiple times */
80		for (p = &environ[offset];; ++p)
81			if (!(*p = *(p + 1)))
82				break;
83	rwlock_unlock(&__environ_lock);
84}
85