Command Line PHP with shell_exec works for root but not others

Question

I have a very simple script that is to test if running a shell_exec (or backtick operator) basically works:

#!/usr/bin/php5
<?php

echo "This is a PHP script\n";
echo `ls -l /home/stoysnet/`;

Unless I run this as root, it always gives me:

$ ./foo.php 
This is a PHP script

Warning: _shell_exec(): Permission Denied in /home/stoysnet/foo.php on line 5

I've tried running this via PHP in a few different ways, but I always get the same error. However, when I put the script into a subdirectory of /etc/ owned by root:root and executed as root it works.

What gives?

Update: Just to clarify:

• I am trying to run it as the stoysnet user via the command line. I am able to execute the command being passed to shell_exec via the same session.
• If I move the script to /etc/somedir/ and execute is as root, it works as expected.
• The script itself runs, just not the backtick operator or shell_exec part
• Execution permissions are set, and 777 doesn't work either.

Answer 1

Are you running this script as a different user than stoysnet? What happens when you do run ls -l /home/stoysnet as the same user that you're executing the PHP script as?

Seems like you need to run the script as a user who has permission to /home/stoysnet/.