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-rw-r--r--src/lib/libc/stdlib/setenv.c106
1 files changed, 106 insertions, 0 deletions
diff --git a/src/lib/libc/stdlib/setenv.c b/src/lib/libc/stdlib/setenv.c
new file mode 100644
index 0000000000..ce0d3f9699
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+++ 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. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31static char *rcsid = "$OpenBSD: setenv.c,v 1.8 2005/03/30 18:51:49 pat Exp $";
32#endif /* LIBC_SCCS and not lint */
33
34#include <stdlib.h>
35#include <string.h>
36
37char *__findenv(const char *name, int *offset);
38
39extern char **environ;
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(const char *name, const char *value, int rewrite)
48{
49 static char **lastenv; /* last value of environ */
50 char *C;
51 int l_value, offset;
52
53 if (*value == '=') /* no `=' in value */
54 ++value;
55 l_value = strlen(value);
56 if ((C = __findenv(name, &offset))) { /* find if already exists */
57 if (!rewrite)
58 return (0);
59 if (strlen(C) >= l_value) { /* old larger; copy over */
60 while ((*C++ = *value++))
61 ;
62 return (0);
63 }
64 } else { /* create new slot */
65 size_t cnt;
66 char **P;
67
68 for (P = environ; *P != NULL; P++)
69 ;
70 cnt = P - environ;
71 P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
72 if (!P)
73 return (-1);
74 if (lastenv != environ)
75 memcpy(P, environ, cnt * sizeof(char *));
76 lastenv = environ = P;
77 offset = cnt;
78 environ[cnt + 1] = NULL;
79 }
80 for (C = (char *)name; *C && *C != '='; ++C)
81 ; /* no `=' in name */
82 if (!(environ[offset] = /* name + `=' + value */
83 malloc((size_t)((int)(C - name) + l_value + 2))))
84 return (-1);
85 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
86 ;
87 for (*C++ = '='; (*C++ = *value++); )
88 ;
89 return (0);
90}
91
92/*
93 * unsetenv(name) --
94 * Delete environmental variable "name".
95 */
96void
97unsetenv(const char *name)
98{
99 char **P;
100 int offset;
101
102 while (__findenv(name, &offset)) /* if set multiple times */
103 for (P = &environ[offset];; ++P)
104 if (!(*P = *(P + 1)))
105 break;
106}