1 /* $OpenBSD: setenv.c,v 1.9 2005/08/08 08:05:37 espie Exp $ */
3 * Copyright (c) 1987 Regents of the University of California.
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31 /* OPENBSD ORIGINAL: lib/libc/stdlib/setenv.c */
34 #if !defined(HAVE_SETENV) || !defined(HAVE_UNSETENV)
39 extern char **environ;
41 /* OpenSSH Portable: __findenv is from getenv.c rev 1.8, made static */
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.
50 __findenv(const char *name, size_t *offset)
52 extern char **environ;
57 if (name == NULL || environ == NULL)
59 for (np = name; *np && *np != '='; ++np)
62 for (p = environ; (cp = *p) != NULL; ++p) {
63 for (np = name, i = len; i && *cp; i--)
66 if (i == 0 && *cp++ == '=') {
67 *offset = p - environ;
77 * Set the value of the environmental variable "name" to be
78 * "value". If rewrite is set, replace any current value.
81 setenv(const char *name, const char *value, int rewrite)
83 static char **lastenv; /* last value of environ */
85 size_t l_value, offset;
87 if (*value == '=') /* no `=' in value */
89 l_value = strlen(value);
90 if ((C = __findenv(name, &offset))) { /* find if already exists */
93 if (strlen(C) >= l_value) { /* old larger; copy over */
94 while ((*C++ = *value++))
98 } else { /* create new slot */
102 for (P = environ; *P != NULL; P++)
105 P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
108 if (lastenv != environ)
109 memcpy(P, environ, cnt * sizeof(char *));
110 lastenv = environ = P;
112 environ[cnt + 1] = NULL;
114 for (C = (char *)name; *C && *C != '='; ++C)
115 ; /* no `=' in name */
116 if (!(environ[offset] = /* name + `=' + value */
117 malloc((size_t)((int)(C - name) + l_value + 2))))
119 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
121 for (*C++ = '='; (*C++ = *value++); )
125 #endif /* HAVE_SETENV */
127 #ifndef HAVE_UNSETENV
130 * Delete environmental variable "name".
133 unsetenv(const char *name)
138 while (__findenv(name, &offset)) /* if set multiple times */
139 for (P = &environ[offset];; ++P)
140 if (!(*P = *(P + 1)))
143 #endif /* HAVE_UNSETENV */
145 #endif /* !defined(HAVE_SETENV) || !defined(HAVE_UNSETENV) */