/*
* unsetenv(name) --
* Delete environmental variable "name".
*/
int
unsetenv(const char *name)
{
size_t l_name;
ssize_t r_offset, w_offset;
_DIAGASSERT(name != NULL);
l_name = __envvarnamelen(name, false);
if (l_name == 0) {
errno = EINVAL;
return -1;
}
if (!__writelockenv())
return -1;
/* Search for the given name in the environment. */
r_offset = __getenvslot(name, l_name, false);
if (r_offset == -1) {
/* Not found. */
(void)__unlockenv();
return 0;
}
__freeenvvar(environ[r_offset]);
/*
* Remove all matches from the environment and free the associated
* memory if possible.
*/
w_offset = r_offset;
while (environ[++r_offset] != NULL) {
if (strncmp(environ[r_offset], name, l_name) != 0 ||
environ[r_offset][l_name] != '=') {
/* Not a match, keep this entry. */
environ[w_offset++] = environ[r_offset];
} else {
/* We found another match. */
__freeenvvar(environ[r_offset]);
}
}
/* Clear out remaining stale entries in the environment vector. */
do {
environ[w_offset++] = NULL;
} while (w_offset < r_offset);
(void)__unlockenv();
return 0;
}
int
putenv(char *str)
{
size_t l_name;
int rv;
_DIAGASSERT(str != NULL);
l_name = __envvarnamelen(str, true);
if (l_name == 0) {
errno = EINVAL;
return -1;
}
rv = -1;
if (__writelockenv()) {
ssize_t offset;
offset = __getenvslot(str, l_name, true);
if (offset != -1) {
if (environ[offset] != NULL)
__freeenvvar(environ[offset]);
environ[offset] = str;
rv = 0;
}
(void)__unlockenv();
}
return rv;
}