2 * Copyright (c) 1987 Regents of the University of California.
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
37 #if defined(LIBC_SCCS) && !defined(lint)
38 static char *rcsid = "$OpenBSD: setenv.c,v 1.5 2002/12/10 22:44:13 mickey Exp $";
39 #endif /* LIBC_SCCS and not lint */
44 char *__findenv(const char *name, int *offset);
48 * Returns pointer to value associated with name, if any, else NULL.
49 * Sets offset to be the offset of the name/value combination in the
50 * environmental array, for use by setenv(3) and unsetenv(3).
51 * Explicitly removes '=' in argument name.
53 * This routine *should* be a static; don't use it.
56 __findenv(name, offset)
57 register const char *name;
60 extern char **environ;
62 register const char *np;
63 register char **p, *cp;
65 if (name == NULL || environ == NULL)
67 for (np = name; *np && *np != '='; ++np)
70 for (p = environ; (cp = *p) != NULL; ++p) {
71 for (np = name, i = len; i && *cp; i--)
74 if (i == 0 && *cp++ == '=') {
75 *offset = p - environ;
84 * Set the value of the environmental variable "name" to be
85 * "value". If rewrite is set, replace any current value.
88 setenv(name, value, rewrite)
89 register const char *name;
90 register const char *value;
93 extern char **environ;
94 static int alloced; /* if allocated space before */
98 if (*value == '=') /* no `=' in value */
100 l_value = strlen(value);
101 if ((C = __findenv(name, &offset))) { /* find if already exists */
104 if (strlen(C) >= l_value) { /* old larger; copy over */
105 while ((*C++ = *value++))
109 } else { /* create new slot */
113 for (P = environ, cnt = 0; *P; ++P, ++cnt);
114 if (alloced) { /* just increase size */
115 P = (char **)realloc((void *)environ,
116 (size_t)(sizeof(char *) * (cnt + 2)));
121 else { /* get new space */
122 alloced = 1; /* copy old entries into it */
123 P = (char **)malloc((size_t)(sizeof(char *) *
127 memmove(P, environ, cnt * sizeof(char *));
130 environ[cnt + 1] = NULL;
133 for (C = (char *)name; *C && *C != '='; ++C); /* no `=' in name */
134 if (!(environ[offset] = /* name + `=' + value */
135 malloc((size_t)((int)(C - name) + l_value + 2))))
137 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
139 for (*C++ = '='; (*C++ = *value++); )
146 * Delete environmental variable "name".
152 extern char **environ;
157 while (__findenv(name, &offset)) /* if set multiple times */
158 for (P = &environ[offset];; ++P)
159 if (!(*P = *(P + 1)))
163 #endif /* HAVE_SETENV */