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
33 * $OpenBSD: setenv.c,v 1.4 2001/07/09 06:57:45 deraadt Exp $
44 * Returns pointer to value associated with name, if any, else NULL.
45 * Sets offset to be the offset of the name/value combination in the
46 * environmental array, for use by setenv(3) and unsetenv(3).
47 * Explicitly removes '=' in argument name.
49 * This routine *should* be a static; don't use it.
52 __findenv(name, offset)
53 register const char *name;
56 extern char **environ;
58 register const char *np;
59 register char **p, *cp;
61 if (name == NULL || environ == NULL)
63 for (np = name; *np && *np != '='; ++np)
66 for (p = environ; (cp = *p) != NULL; ++p) {
67 for (np = name, i = len; i && *cp; i--)
70 if (i == 0 && *cp++ == '=') {
71 *offset = p - environ;
80 * Set the value of the environmental variable "name" to be
81 * "value". If rewrite is set, replace any current value.
84 setenv(name, value, rewrite)
85 register const char *name;
86 register const char *value;
89 extern char **environ;
90 static int alloced; /* if allocated space before */
95 if (*value == '=') /* no `=' in value */
97 l_value = strlen(value);
98 if ((C = __findenv(name, &offset))) { /* find if already exists */
101 if (strlen(C) >= l_value) { /* old larger; copy over */
102 while ((*C++ = *value++))
106 } else { /* create new slot */
110 for (P = environ, cnt = 0; *P; ++P, ++cnt);
111 if (alloced) { /* just increase size */
112 P = (char **)realloc((void *)environ,
113 (size_t)(sizeof(char *) * (cnt + 2)));
118 else { /* get new space */
119 alloced = 1; /* copy old entries into it */
120 P = (char **)malloc((size_t)(sizeof(char *) *
124 memmove(P, environ, cnt * sizeof(char *));
127 environ[cnt + 1] = NULL;
130 for (C = (char *)name; *C && *C != '='; ++C); /* no `=' in name */
131 if (!(environ[offset] = /* name + `=' + value */
132 malloc((size_t)((int)(C - name) + l_value + 2))))
134 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
136 for (*C++ = '='; (*C++ = *value++); )
143 * Delete environmental variable "name".
149 extern char **environ;
154 while (__findenv(name, &offset)) /* if set multiple times */
155 for (P = &environ[offset];; ++P)
156 if (!(*P = *(P + 1)))
160 #endif /* HAVE_SETENV */