domain regex split

Question

I have some domains I want to split but can\'t figure out the regex...

I have:

• http://www.google.com/tomato
• http://int.google.c

Answer 1

You can do this on a best bet basis. The last part of the URL is always the TLD (and optional root). And you are basically looking for any preceeding word that is longer than 2 letters:

$url = "http://www.google.co.uk./search?q=..";

preg_match("#http://
            (?:[^/]+\.)*       # cut off any preceeding www*
            ([\w-]{3,})        # main domain name
            (\.\w\w)?          # two-letter second level domain .co
            \.\w+\.?           # TLD
            (/|:|$)            # end regex with / or : or string end
            #x", 
      $url, $match);

If you expect any longer second-level domains (.com maybe?) then add another \w. But this is not very generic, you would actually need a list for TLDs were this was allowed.