1/*	$NetBSD: getenv.c,v 1.34 2010/11/14 20:37:02 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[] = "@(#)getenv.c	8.1 (Berkeley) 6/4/93";
36#else
37__RCSID("$NetBSD: getenv.c,v 1.34 2010/11/14 20:37:02 tron Exp $");
38#endif
39#endif /* LIBC_SCCS and not lint */
40
41#include "namespace.h"
42#include <assert.h>
43#include <errno.h>
44#include <stdlib.h>
45#include <string.h>
46
47#include "env.h"
48#include "reentrant.h"
49#include "local.h"
50
51__weak_alias(getenv_r, _getenv_r)
52
53/*
54 * getenv --
55 *	Returns ptr to value associated with name, if any, else NULL.
56 *	XXX: we cannot use getenv_r to implement this, because getenv()
57 *	cannot use a shared buffer, because if it did, subsequent calls
58 *	to getenv would trash previous results.
59 */
60char *
61getenv(const char *name)
62{
63	size_t l_name;
64	char *result;
65
66	_DIAGASSERT(name != NULL);
67
68	l_name = __envvarnamelen(name, false);
69	if (l_name == 0)
70		return NULL;
71
72	result = NULL;
73	if (__readlockenv()) {
74		result = __findenvvar(name, l_name);
75		(void)__unlockenv();
76	}
77
78	return result;
79}
80
81int
82getenv_r(const char *name, char *buf, size_t len)
83{
84	size_t l_name;
85	int rv;
86
87	_DIAGASSERT(name != NULL);
88
89	l_name = __envvarnamelen(name, false);
90	if (l_name == 0) {
91		errno = ENOENT;
92		return -1;
93	}
94
95	rv = -1;
96	if (__readlockenv()) {
97		const char *value;
98
99		value = __findenvvar(name, l_name);
100		if (value != NULL) {
101			if (strlcpy(buf, value, len) < len) {
102				rv = 0;
103			} else {
104				errno = ERANGE;
105			}
106		} else {
107			errno = ENOENT;
108		}
109		(void)__unlockenv();
110	}
111
112	return rv;
113}
114