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-rw-r--r--src/lib/libc/stdlib/setenv.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/src/lib/libc/stdlib/setenv.c b/src/lib/libc/stdlib/setenv.c
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1/*
2 * Copyright (c) 1987 Regents of the University of California.
3 * 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)
35static char *rcsid = "$OpenBSD: setenv.c,v 1.3 1998/02/02 22:44:53 millert Exp $";
36#endif /* LIBC_SCCS and not lint */
37
38#include <stdlib.h>
39#include <string.h>
40
41/*
42 * setenv --
43 * Set the value of the environmental variable "name" to be
44 * "value". If rewrite is set, replace any current value.
45 */
46int
47setenv(name, value, rewrite)
48 register const char *name;
49 register const char *value;
50 int rewrite;
51{
52 extern char **environ;
53 static int alloced; /* if allocated space before */
54 register char *C;
55 int l_value, offset;
56 char *__findenv();
57
58 if (*value == '=') /* no `=' in value */
59 ++value;
60 l_value = strlen(value);
61 if ((C = __findenv(name, &offset))) { /* find if already exists */
62 if (!rewrite)
63 return (0);
64 if (strlen(C) >= l_value) { /* old larger; copy over */
65 while (*C++ = *value++);
66 return (0);
67 }
68 } else { /* create new slot */
69 register int cnt;
70 register char **P;
71
72 for (P = environ, cnt = 0; *P; ++P, ++cnt);
73 if (alloced) { /* just increase size */
74 P = (char **)realloc((void *)environ,
75 (size_t)(sizeof(char *) * (cnt + 2)));
76 if (!P)
77 return (-1);
78 environ = P;
79 }
80 else { /* get new space */
81 alloced = 1; /* copy old entries into it */
82 P = (char **)malloc((size_t)(sizeof(char *) *
83 (cnt + 2)));
84 if (!P)
85 return (-1);
86 bcopy(environ, P, cnt * sizeof(char *));
87 environ = P;
88 }
89 environ[cnt + 1] = NULL;
90 offset = cnt;
91 }
92 for (C = (char *)name; *C && *C != '='; ++C); /* no `=' in name */
93 if (!(environ[offset] = /* name + `=' + value */
94 malloc((size_t)((int)(C - name) + l_value + 2))))
95 return (-1);
96 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
97 ;
98 for (*C++ = '='; *C++ = *value++; )
99 ;
100 return (0);
101}
102
103/*
104 * unsetenv(name) --
105 * Delete environmental variable "name".
106 */
107void
108unsetenv(name)
109 const char *name;
110{
111 extern char **environ;
112 register char **P;
113 int offset;
114 char *__findenv();
115
116 while (__findenv(name, &offset)) /* if set multiple times */
117 for (P = &environ[offset];; ++P)
118 if (!(*P = *(P + 1)))
119 break;
120}