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-rw-r--r--src/lib/libc/stdlib/setenv.c122
1 files changed, 122 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 1.5 2002/12/10 22:44:13 mickey Exp $";
36#endif /* LIBC_SCCS and not lint */
37
38#include <stdlib.h>
39#include <string.h>
40
41char *__findenv(const char *name, int *offset);
42
43/*
44 * setenv --
45 * Set the value of the environmental variable "name" to be
46 * "value". If rewrite is set, replace any current value.
47 */
48int
49setenv(name, value, rewrite)
50 register const char *name;
51 register const char *value;
52 int rewrite;
53{
54 extern char **environ;
55 static int alloced; /* if allocated space before */
56 register char *C;
57 int l_value, offset;
58
59 if (*value == '=') /* no `=' in value */
60 ++value;
61 l_value = strlen(value);
62 if ((C = __findenv(name, &offset))) { /* find if already exists */
63 if (!rewrite)
64 return (0);
65 if (strlen(C) >= l_value) { /* old larger; copy over */
66 while ((*C++ = *value++))
67 ;
68 return (0);
69 }
70 } else { /* create new slot */
71 register int cnt;
72 register char **P;
73
74 for (P = environ, cnt = 0; *P; ++P, ++cnt);
75 if (alloced) { /* just increase size */
76 P = (char **)realloc((void *)environ,
77 (size_t)(sizeof(char *) * (cnt + 2)));
78 if (!P)
79 return (-1);
80 environ = P;
81 }
82 else { /* get new space */
83 alloced = 1; /* copy old entries into it */
84 P = (char **)malloc((size_t)(sizeof(char *) *
85 (cnt + 2)));
86 if (!P)
87 return (-1);
88 bcopy(environ, P, cnt * sizeof(char *));
89 environ = P;
90 }
91 environ[cnt + 1] = NULL;
92 offset = cnt;
93 }
94 for (C = (char *)name; *C && *C != '='; ++C); /* no `=' in name */
95 if (!(environ[offset] = /* name + `=' + value */
96 malloc((size_t)((int)(C - name) + l_value + 2))))
97 return (-1);
98 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
99 ;
100 for (*C++ = '='; (*C++ = *value++); )
101 ;
102 return (0);
103}
104
105/*
106 * unsetenv(name) --
107 * Delete environmental variable "name".
108 */
109void
110unsetenv(name)
111 const char *name;
112{
113 extern char **environ;
114 register char **P;
115 int offset;
116 char *__findenv();
117
118 while (__findenv(name, &offset)) /* if set multiple times */
119 for (P = &environ[offset];; ++P)
120 if (!(*P = *(P + 1)))
121 break;
122}