How do you strip out the domain name from a URL in php?

Question

Im looking for a method (or function) to strip out the domain.ext part of any URL thats fed into the function. The domain extension can be anything (.com, .co.uk, .nl, .what

Answer 1

I spent some time thinking about whether it makes sense to use a regular expression for this, but in the end I think not.

firstresponder's regexp came close to convincing me it was the best way, but it didn't work on anything missing a trailing slash (so http://example.com, for instance). I fixed that with the following: '/\w+\..{2,3}(?:\..{2,3})?(?=[\/\W])/i', but then I realized that matches twice for urls like 'http://example.com/index.htm'. Oops. That wouldn't be so bad (just use the first one), but it also matches twice on something like this: 'http://abc.ed.fg.hij.kl.mn/', and the first match isn't the right one. :(

A co-worker suggested just getting the host (via parse_url()), and then just taking the last two or three array bits (split() on '.') The two or three would be based on a list of domains, like 'co.uk', etc. Making up that list becomes the hard part.