(PHP 4, PHP 5)
posix_setgid — Set the GID of the current process
$gid
)Set the real group ID of the current process. This is a privileged function and needs appropriate privileges (usually root) on the system to be able to perform this function. The appropriate order of function calls is posix_setgid() first, posix_setuid() last.
Note:
If the caller is a super user, this will also set the effective group id.
gid
The group id.
成功时返回 TRUE， 或者在失败时返回 FALSE。
Example #1 posix_setgid() example
This example will print out the effective group id, once it is changed.
<?php
echo 'My real group id is '.posix_getgid(); //20
posix_setgid(40);
echo 'My real group id is '.posix_getgid(); //40
echo 'My effective group id is '.posix_getegid(); //40
?>
jac (2011-05-26 10:26:24)
if you're going to use this along with posix_setuid, make sure you call posix_setgid first:
<?php
define (PROC_USER, 'john');
define (PROC_GRP, 'admins');
?>
following works:
<?php
$user = posix_getpwnam( PROC_USER );
$group = posix_getgrnam( PROC_GRP);
echo posix_getuid()."\n";
echo posix_getgid()."\n";
posix_setgid($group['gid']);
posix_setuid($user['uid']);
echo posix_getuid()."\n";
echo posix_getgid()."\n";
?>
following will not set gid
<?php
$user = posix_getpwnam( PROC_USER );
$group = posix_getgrnam( PROC_GRP);
echo posix_getuid()."\n";
echo posix_getgid()."\n";
posix_setuid($user['uid']);
posix_setgid($group['gid']);
echo posix_getuid()."\n";
echo posix_getgid()."\n";
?>