posix_setgid

(PHP 4, PHP 5, PHP 7, PHP 8)

posix_setgid — Set the GID of the current process

说明

posix_setgid ( int $group_id ) : bool

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.

参数

group_id: The group id.

返回值

成功时返回 true，或者在失败时返回 false。

范例

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
?>

参见

posix_getgrgid() - Return info about a group by group id
posix_getgid() - Return the real group ID of the current process

User Contributed Notes

jac 26-May-2011 10:26


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";


?>