shell_exec( ) function problem

[hsceeus]

i trying to use shell_exec on a unix-type platform and can't seem to get it to work. Can anyone help me with the shell_exec command problem? below is the coding of my:

<?php

$output=shell_exec('ll -lart');

echo "$output";
?>

suppose when i run this two line of php coding, there should be a output displayed. but no output displayed.
CAn somebody help me? please?

[omoutop]

are u using it in safe mode? If yes it wont work

[coopster]

Welcome to WebmasterWorld, hsceeus.

You can also turn up your error_reporting [php.net] during development to see any errors.