Overview
KB
Technical FAQ
PHP Manual
CSS2 Manual
HTML Manual
JS Guide
JS Reference
PhpDock Manual
Nu-Coder Manual
PhpExpress Manual
PHP Joomla
Development
Learn PHP
 
<posix_setsidposix_strerror>
^POSIX FunctionsLast updated: Mon, 26 Oct 2026

posix_setuid

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

posix_setuid — Set the UID of the current process

Description

function posix_setuid(int $user_id): bool

Set the real user ID of the current process. This is a privileged function that needs appropriate privileges (usually root) on the system to be able to perform this function.

Parameters

user_id

The user id.

Return Values

Returns true on success or false on failure.

Examples

Example #1 posix_setuid() example

This example will show the current user id and then set it to a different value.

<?php
echo posix_getuid()."\n"; //10001
echo posix_geteuid()."\n"; //10001
posix_setuid(10000);
echo posix_getuid()."\n"; //10000
echo posix_geteuid()."\n"; //10000
?>

See Also


<posix_setsidposix_strerror>
^POSIX FunctionsLast updated: Mon, 26 Oct 2026