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 * 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.
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
34 #if defined(LIBC_SCCS) && !defined(lint)
36 static char sccsid[] = "@(#)setenv.c 8.1 (Berkeley) 6/4/93";
38 static const char rcsid[] = "$FreeBSD: src/lib/libc/stdlib/setenv.c,v 1.5.2.1 2000/09/20 19:46:03 brian Exp $";
39 #endif /* LIBC_SCCS and not lint */
45 char *__findenv __P((const char *, int *));
49 * Set the value of the environmental variable "name" to be
50 * "value". If rewrite is set, replace any current value.
53 setenv(name, value, rewrite)
54 register const char *name;
55 register const char *value;
58 extern char **environ;
59 static char **alloced; /* if allocated space before */
63 if (*value == '=') /* no `=' in value */
65 l_value = strlen(value);
66 if ((c = __findenv(name, &offset))) { /* find if already exists */
69 if (strlen(c) >= l_value) { /* old larger; copy over */
70 while ( (*c++ = *value++) );
73 } else { /* create new slot */
77 for (p = environ, cnt = 0; *p; ++p, ++cnt);
78 if (alloced == environ) { /* just increase size */
79 p = (char **)realloc((char *)environ,
80 (size_t)(sizeof(char *) * (cnt + 2)));
83 alloced = environ = p;
85 else { /* get new space */
86 /* copy old entries into it */
87 p = malloc((size_t)(sizeof(char *) * (cnt + 2)));
90 bcopy(environ, p, cnt * sizeof(char *));
91 alloced = environ = p;
93 environ[cnt + 1] = NULL;
96 for (c = (char *)name; *c && *c != '='; ++c); /* no `=' in name */
97 if (!(environ[offset] = /* name + `=' + value */
98 malloc((size_t)((int)(c - name) + l_value + 2))))
100 for (c = environ[offset]; (*c = *name++) && *c != '='; ++c);
101 for (*c++ = '='; (*c++ = *value++); );
107 * Delete environmental variable "name".
113 extern char **environ;
117 while (__findenv(name, &offset)) /* if set multiple times */
118 for (p = &environ[offset];; ++p)
119 if (!(*p = *(p + 1)))