getting function’s argument names

You can use Reflection :

function get_func_argNames($funcName) {
    $f = new ReflectionFunction($funcName);
    $result = array();
    foreach ($f->getParameters() as $param) {
        $result[] = $param->name;   
    }
    return $result;
}

print_r(get_func_argNames('get_func_argNames'));


//output
Array
(
    [0] => funcName
)