1 /* $NetBSD: getenv.c,v 1.37 2022/02/11 21:36:46 rillig 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
35 static char sccsid[] = "@(#)getenv.c 8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: getenv.c,v 1.37 2022/02/11 21:36:46 rillig 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 "local.h"
49
__weak_alias(getenv_r,_getenv_r)50 __weak_alias(getenv_r, _getenv_r)
51
52 /*
53 * getenv --
54 * Returns ptr to value associated with name, if any, else NULL.
55 * XXX: we cannot use getenv_r to implement this, because getenv()
56 * cannot use a shared buffer, because if it did, subsequent calls
57 * to getenv would trash previous results.
58 */
59 char *
60 getenv(const char *name)
61 {
62 size_t l_name;
63 char *result;
64
65 _DIAGASSERT(name != NULL);
66
67 l_name = __envvarnamelen(name, false);
68 if (l_name == 0)
69 return NULL;
70
71 result = NULL;
72 if (__readlockenv()) {
73 result = __findenvvar(name, l_name);
74 (void)__unlockenv();
75 }
76
77 return result;
78 }
79
80 int
getenv_r(const char * name,char * buf,size_t len)81 getenv_r(const char *name, char *buf, size_t len)
82 {
83 size_t l_name;
84 int rv;
85
86 _DIAGASSERT(name != NULL);
87
88 l_name = __envvarnamelen(name, false);
89 if (l_name == 0) {
90 errno = ENOENT;
91 return -1;
92 }
93
94 rv = -1;
95 if (__readlockenv()) {
96 const char *value;
97
98 value = __findenvvar(name, l_name);
99 if (value != NULL) {
100 if (strlcpy(buf, value, len) < len) {
101 rv = 0;
102 } else {
103 errno = ERANGE;
104 }
105 } else {
106 errno = ENOENT;
107 }
108 (void)__unlockenv();
109 }
110
111 return rv;
112 }
113