regex to find url in a text

Question

I have to find the first url in the text with a regular expression:

for example:

I love this website:http://www.youtube.com/music it's fantastic

or

[ es. http://www.youtube.com/music] text

Answer 1

I looked into this issue last year and developed a solution that you may want to look at - See: URL Linkification (HTTP/FTP) This link is a test page for the Javascript solution with many examples of difficult-to-linkify URLs.

My regex solution, written for both PHP and Javascript - is not simple (but neither is the problem as it turns out.) For more information I would recommend also reading:

The Problem With URLs by Jeff Atwood, and
An Improved Liberal, Accurate Regex Pattern for Matching URLs by John Gruber

The comments following Jeff's blog post are a must read if you want to do this right...

Note that this question gets asked a lot. Maybe do a search next time :)

Answer 2

You can't do this perfectly with a regular expression. You may be interested in this blog post. There is a bit more information on Regex Guru, but even those look very fragile. You will need to have additional checks outside of your regular expression to catch the edge cases.

Answer 3

Identifying URLs is tricky because they are often surrounded by punctuation marks and because users frequently do not use the full form of the URL. Many JavaScript functions exist for replacing URLs with hyperlinks, but I was unable to find one that works as well as the urlize filter in the Python-based web framework Django. I therefore ported Django's urlize function to JavaScript: https://github.com/ljosa/urlize.js

It actually would not pick up the URL in your example because there is a colon right before the URL. But if we modify the example a little:

urlize("I love this website: http://www.youtube.com/music it's fantastic", true, true)
=> 'I love this website: <a href="http://www.youtube.com/music" rel="nofollow">http://www.youtube.com/music</a> it&#39;s fantastic"'

Note the second argument which, if true, inserts rel="nofollow" and the third argument which, if true, quotes characters that have special meaning in HTML.

Answer 4

This might work->

\b(([\w-]+://?|www[.])[^\s()<>]+(?:\([\w\d]+\)|([^[:punct:]\s]|/)))

Found it somewhere

Will find links ->

http://foo.com/blah_blah/

(Something like http://foo.com/blah_blah)

http://foo.com/blah_blah_(wikipedia)

Hope this works....