PHP: register_globals replacement

function registerGlobals($order = 'egpcs') {
    // don't fill global scope with garbage. it's 5.4 - use closures
    $register = function (array $superglobal) {
        foreach ($superglobal as $varname => $value) {
            global $$varname;
            $$varname = $value;
        }
    };

    $mapping = [
        'e' => $_ENV,
        'g' => $_GET,
        'p' => $_POST,
        'c' => $_COOKIE,
        's' => $_SERVER,
    ];

    $order  = strtolower($order);
    $length = strlen($order);

    for ($index = 0; $index < $length; $index++) {
        $register($mapping[$order[$index]]);
    }
}