2 * Copyright (c) 1987, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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 * 4. 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.
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
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)setenv.c 8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
40 char *__findenv(const char *, int *);
44 * Set the value of the environmental variable "name" to be
45 * "value". If rewrite is set, replace any current value.
48 setenv(name, value, rewrite)
53 extern char **environ;
54 static char **alloced; /* if allocated space before */
58 if (*value == '=') /* no `=' in value */
60 l_value = strlen(value);
61 if ((c = __findenv(name, &offset))) { /* find if already exists */
64 if (strlen(c) >= l_value) { /* old larger; copy over */
65 while ( (*c++ = *value++) );
68 } else { /* create new slot */
72 for (p = environ, cnt = 0; *p; ++p, ++cnt);
73 if (alloced == environ) { /* just increase size */
74 p = (char **)realloc((char *)environ,
75 (size_t)(sizeof(char *) * (cnt + 2)));
78 alloced = environ = p;
80 else { /* get new space */
81 /* copy old entries into it */
82 p = malloc((size_t)(sizeof(char *) * (cnt + 2)));
85 bcopy(environ, p, cnt * sizeof(char *));
86 alloced = environ = p;
88 environ[cnt + 1] = NULL;
91 for (c = (char *)name; *c && *c != '='; ++c); /* no `=' in name */
92 if (!(environ[offset] = /* name + `=' + value */
93 malloc((size_t)((int)(c - name) + l_value + 2))))
95 for (c = environ[offset]; (*c = *name++) && *c != '='; ++c);
96 for (*c++ = '='; (*c++ = *value++); );
102 * Delete environmental variable "name".
108 extern char **environ;
112 while (__findenv(name, &offset)) /* if set multiple times */
113 for (p = &environ[offset];; ++p)
114 if (!(*p = *(p + 1)))