Regular Expression to match both relative and absolute URLs

Question

Anyone want to try their hand at coming up with a regex that matches both:

• /foo/bar/baz.gif
• /foo/bar/
• http://www.foo.com/foo/bar

I

Answer 1

I used naming capture groups. We get better matches when the scheme is present. Like www.foo.com/bar would only match /bar.

(?:
  (?:(?https?|file)://)
  (?[^/]+)
  (?/(?:[^\s])+)?
)
|
(?/(?:[^\s])+)

This is what you could do for javascript

var result = text.match(/(?:(?:(https?|file):\/\/)([^\/]+)(\/(?:[^\s])+)?)|(\/(?:[^\s])+)/g);

Test data

sadfasdf /foo/bar/ba090z.gif asdfasdf /foo/bar/ sadfasdf asdflkj; http://www.foo.com/foo/bar some stuff http://user:pw@www.foo.com:80/r?stuff%20stuff

user:pw@www.foo.com:80/r?stuff%20stuff