// https://gist.github.com/tlongren/5527129

setlocale(LC_ALL, 'en_US.UTF8');
function slug_url($str, $delimiter='-') {
	$clean = iconv('UTF-8', 'ASCII//TRANSLIT', $str);
	$clean = preg_replace("/[^a-zA-Z0-9\/_|+ -]/", '', $clean);
	$clean = strtolower(trim($clean, '-'));
	$clean = preg_replace("/[\/_|+ -]+/", $delimiter, $clean);
	return $clean;
}

echo slug_url("Qu'en est-il français? Ça marche alors?");
// return: quen-est-il-francais-ca-marche-alors