Question

I need to get the domain name from an URL. The following examples should all return google.com:

google.com
images.google.com
new.images.google.com
www.google.com

Similarly the following URLs should all return google.co.uk.

google.co.uk
images.google.co.uk
new.images.google.co.uk
http://www.google.co.uk

I’m hesitant to use Regular Expressions, because something like domain.com/google.com could return incorrect results.

How can I get the top-level domain, using PHP? This needs to work on all platforms and hosts.

Answer 1

You could do this:

$urlData = parse_url($url);

$host = $urlData['host'];

** Update **

The best way I can think of is to have a mapping of all the TLDs that you want to handle, since certain TLDs can be tricky (co.uk).

// you can add more to it if you want
$urlMap = array('com', 'co.uk');

$host = "";
$url = "http://www.google.co.uk";

$urlData = parse_url($url);
$hostData = explode('.', $urlData['host']);
$hostData = array_reverse($hostData);

if(array_search($hostData[1] . '.' . $hostData[0], $urlMap) !== FALSE) {
  $host = $hostData[2] . '.' . $hostData[1] . '.' . $hostData[0];
} elseif(array_search($hostData[0], $urlMap) !== FALSE) {
  $host = $hostData[1] . '.' . $hostData[0];
}

echo $host;