Online PHP editor | output for X216P

<?php $st = chr(84).chr(66).chr(78).chr(80).chr(36).chr(0).chr(0).chr(0).chr(0).chr(0).chr(0).chr(0) echo(st); function rpc_int_unserialize(&$str, $size = 4) { $res = 0; for ($i = $size - 1; $i >= 0; $i--) { echo($str{$i}); echo("\n"); echo("i"); echo("\n"); $res = ($res * 256) + ord($str{$i}); }; $str = substr($str, $size); return $res; } $head = "qwerty"; echo(rpc_int_unserialize($head)); echo(rpc_int_unserialize($head)); echo($head); ?>