2 * Copyright (c) 1987, 1993
3 * The Regents of the University of California. All rights reserved.
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15 * This product includes software developed by the University of
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33 * @(#)setenv.c 8.1 (Berkeley) 6/4/93
34 * $FreeBSD: src/lib/libc/stdlib/setenv.c,v 1.5.2.1 2000/09/20 19:46:03 brian Exp $
35 * $DragonFly: src/lib/libc/stdlib/setenv.c,v 1.4 2003/09/06 08:19:16 asmodai Exp $
42 char *__findenv (const char *, int *);
46 * Set the value of the environmental variable "name" to be
47 * "value". If rewrite is set, replace any current value.
50 setenv(name, value, rewrite)
55 extern char **environ;
56 static char **alloced; /* if allocated space before */
60 if (*value == '=') /* no `=' in value */
62 l_value = strlen(value);
63 if ((c = __findenv(name, &offset))) { /* find if already exists */
66 if (strlen(c) >= l_value) { /* old larger; copy over */
67 while ( (*c++ = *value++) );
70 } else { /* create new slot */
74 for (p = environ, cnt = 0; *p; ++p, ++cnt);
75 if (alloced == environ) { /* just increase size */
76 p = (char **)realloc((char *)environ,
77 (size_t)(sizeof(char *) * (cnt + 2)));
80 alloced = environ = p;
82 else { /* get new space */
83 /* copy old entries into it */
84 p = malloc((size_t)(sizeof(char *) * (cnt + 2)));
87 bcopy(environ, p, cnt * sizeof(char *));
88 alloced = environ = p;
90 environ[cnt + 1] = NULL;
93 for (c = (char *)name; *c && *c != '='; ++c); /* no `=' in name */
94 if (!(environ[offset] = /* name + `=' + value */
95 malloc((size_t)((int)(c - name) + l_value + 2))))
97 for (c = environ[offset]; (*c = *name++) && *c != '='; ++c);
98 for (*c++ = '='; (*c++ = *value++); );
104 * Delete environmental variable "name".
110 extern char **environ;
114 while (__findenv(name, &offset)) /* if set multiple times */
115 for (p = &environ[offset];; ++p)
116 if (!(*p = *(p + 1)))