compat_unsetenv.c revision 1.3 
1/*	$NetBSD: compat_unsetenv.c,v 1.3 2010/11/14 18:11:42 tron 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 1.3 2010/11/14 18:11:42 tron 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 <bitstring.h>
50#include "reentrant.h"
51#include "local.h"
52
53#ifdef __weak_alias
54__weak_alias(unsetenv,_unsetenv)
55#endif
56
57#include "env.h"
58
59__warn_references(unsetenv,
60    "warning: reference to compatibility unsetenv();"
61    " include <stdlib.h> for correct reference")
62
63/*
64 * unsetenv(name) --
65 *	Delete environmental variable "name".
66 */
67void
68unsetenv(const char *name)
69{
70	size_t l_name;
71
72	_DIAGASSERT(name != NULL);
73
74	l_name = strlen(name);
75	if (__writelockenv()) {
76		ssize_t offset;
77
78		while ((offset = __getenvslot(name, l_name, false)) != -1) {
79			char **p;
80			for (p = &environ[offset]; ; ++p) {
81				if ((*p = *(p + 1)) == NULL)
82					break;
83			}
84		}
85		(void)__unlockenv();
86	}
87}
88