getenv.c - vx32 - Local 9vx git repository for patches.
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---
getenv.c (2846B)
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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 #include <stdlib.h>
35 #include <stddef.h>
36 #include <string.h>
37
38 char *__findenv(const char *, int *);
39
40 /*
41 * __findenv --
42 * Returns pointer to value associated with name, if any, else NULL.
43 * Sets offset to be the offset of the name/value combination in the
44 * environmental array, for use by setenv(3) and unsetenv(3).
45 * Explicitly removes '=' in argument name.
46 */
47 char *
48 __findenv(const char *name, int *offset)
49 {
50 extern char **environ;
51 int len, i;
52 const char *np;
53 char **p, *cp;
54
55 if (name == NULL || environ == NULL)
56 return (NULL);
57 for (np = name; *np && *np != '='; ++np)
58 continue;
59 len = np - name;
60 for (p = environ; (cp = *p) != NULL; ++p) {
61 for (np = name, i = len; i && *cp; i--)
62 if (*cp++ != *np++)
63 break;
64 if (i == 0 && *cp++ == '=') {
65 *offset = p - environ;
66 return (cp);
67 }
68 }
69 return (NULL);
70 }
71
72 /*
73 * getenv --
74 * Returns ptr to value associated with name, if any, else NULL.
75 */
76 char *
77 getenv(name)
78 const char *name;
79 {
80 int offset;
81
82 return (__findenv(name, &offset));
83 }