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1 /*
2 * Copyright (c) 1987, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)getenv.c 8.1 (Berkeley) 6/4/93";
36 #endif /* LIBC_SCCS and not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: src/lib/libc/stdlib/getenv.c,v 1.4 2002/03/21 22:48:41 obrien Exp $");
39
40 #include <stdlib.h>
41 #include <stddef.h>
42 #include <string.h>
43
44 inline char *__findenv(const char *, int *);
45
46 /*
47 * __findenv --
48 * Returns pointer to value associated with name, if any, else NULL.
49 * Sets offset to be the offset of the name/value combination in the
50 * environmental array, for use by setenv(3) and unsetenv(3).
51 * Explicitly removes '=' in argument name.
52 *
53 * This routine *should* be a static; don't use it.
54 */
55 inline char *
56 __findenv(name, offset)
57 const char *name;
58 int *offset;
59 {
60 extern char **environ;
61 int len, i;
62 const char *np;
63 char **p, *cp;
64
65 if (name == NULL || environ == NULL)
66 return (NULL);
67 for (np = name; *np && *np != '='; ++np)
68 continue;
69 len = np - name;
70 for (p = environ; (cp = *p) != NULL; ++p) {
71 for (np = name, i = len; i && *cp; i--)
72 if (*cp++ != *np++)
73 break;
74 if (i == 0 && *cp++ == '=') {
75 *offset = p - environ;
76 return (cp);
77 }
78 }
79 return (NULL);
80 }
81
82 /*
83 * getenv --
84 * Returns ptr to value associated with name, if any, else NULL.
85 */
86 char *
87 getenv(name)
88 const char *name;
89 {
90 int offset;
91
92 return (__findenv(name, &offset));
93 }