Untitled

$data = parse_url('http://'.$_GET['url']);
$qq = $data['scheme'].'://'.$data['host'];

if(preg_match('/^(?:www\.)?[a-z](?:[a-z0-9-]*[a-z0-9])?\.(?:[a-z0-9])+(?:\.[a-z0-9]*)$/i', $data['host'],$nmatches)==0){
  echo 'no match';
}else{
  //do code
}