PHP从字符串获取带有子域的域

Question

Im using the following function to cut domain from string:

function get_domain($url)
{
  $pieces = parse_url($url);
  $domain = isset($pieces['host']) ? $pieces['host'] : '';
  if (preg_match('/(?P<domain>[a-z0-9][a-z0-9\-]{1,63}\.[a-z\.]{2,6})$/i', $domain, $regs)) {
    return $regs['domain'];
  }
  return false;
}

I need to cut subdomain + domain how should i change preg_match to get it?

PS i was searching solution but everyone wants to cut only domain without sub.

Answer 1

If you can't work out the regexp, a more procedural approach might be:

$pieces = parse_url($url);
$aDomains = explode('.', $pieces['host']);
$sub = array_shift($aDomains);
$restofdomain = implode($aDomains);

...if you're always going to just want the first domain (ie it wouldn't work with a root domain like 'somedomain.com'.