PHP system() command doesn't to work on localhost

Question

I have this code:

<?php
system('shutdown -s');
?>

It works just fine, shuts down my localhost and everything. But this doesn't lock the computer:

<?php    
system('Rundll32.exe System32\User32.dll,LockWorkStation');
?>

Why doesn't it work?

Sorry, the code wasn't formatted correctly the first time for some reason. — Zachrip
– Zachrip, Commented Jul 4, 2012 at 0:34
Did you try your second command in a simple DOS prompt? (outside of PHP) — Jocelyn
– Jocelyn, Commented Jul 4, 2012 at 0:44
Does it work better using the full path to Rundll32.exe? On my computer it is "C:\WINNT\system32\Rundll32.exe", you'll have to check what is the correct path on your computer. Also maybe with forward slashes instead of backslashes... — Jocelyn
– Jocelyn, Commented Jul 4, 2012 at 1:06

Ignacio Vazquez-Abrams · Accepted Answer · 2012-07-04 16:11:16Z

1

The web server isn't running in the user session, and so has no ability to lock it.

answered Jul 4, 2012 at 16:11

804k160 gold badges1.4k silver badges1.4k bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Because the system can be shut down by anything with appropriate privileges; doing so doesn't require a user session.

Okay, do you have any other suggestions on how I could lock the computer?

Run a user daemon that performs the lock instead, and communicate with it using mailslots or the like.