exec(), passthru(), system() etc.

<?php


echo '<pre>';
exec('ls -la', $result);
print_r($result);
echo '<hr/>';


$result = passthru('ls -la');
echo '<hr/>';


$result = system('ls -la');
echo '<hr/>';


echo $result = `ls -la`;
echo '<hr/>';


print_r(getenv('HTTP_REFERER'));


putenv("HOME=$home");