error_reporting(E_ALL);
ini_set('display_errors', 'on');

function fatal_error_handler($buffer) {
    header('HTTP/1.1 500 Internal Server Error');
    exit(0);
}

function handle_error ($errno, $errstr, $errfile, $errline){
    header('HTTP/1.1 500 Internal Server Error');
    exit(0);
}

ob_start("fatal_error_handler");
set_error_handler("handle_error");

//would normally cause a fatal error, but instead our output handler will be called allowing us to handle the error.
somefunction();
ob_end_flush();