Get domain name without Tld

$domain = 'dailymail.co.uk';
$dots = substr_count($domain, '.');
if($dots == 1){
$results = preg_split('/(?=.[^.]+$)/', $domain);
echo $results[0];
}
if($dots == 2){
$results = preg_split('/(?<=[^0-9])[.](?<![0-9])/', $domain);
echo $results[0];
}