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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
M4rk
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  • Here's a PHP version of your question: [Extract URL from string](http://stackoverflow.com/questions/4390556/extract-url-from-string) – Matt Ball Mar 28 '11 at 16:01

7 Answers7

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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 :)

ridgerunner
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  • Thanks for making this available, I found it very useful. Any chance you've come up with a similarly robust regEx that finds urls without the leading 'http://', like 'www.example.com'?. – mksuth Aug 25 '11 at 21:38
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    @mksuth - Check out John Gruber's regex at the link above. It will catch URLs without the `http://`. – ridgerunner Aug 28 '11 at 05:26
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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.

asthasr
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    I think it would be more accurate to say that you can't do this *perfectly* and you can't do it with regex *alone*. FWIW, Stack Overflow's WMD editor uses a similar solution to the one Jeff Atwood describes in your first link, using a combination of a regex and various checks. Like I said, it can't be perfect but for lack of a better solution you might as well use something that will match 99.9% of the time. – Andy E Mar 28 '11 at 16:14
  • Interesting stuff, but I'd say that the blanket comment "can't do this" is a little strong. More like, "can do this 99% of the time" :) – James McCormack Mar 28 '11 at 16:14
  • I agree with your comments. I have edited the answer to reflect that. – asthasr Mar 28 '11 at 16:16
2

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.

Vebjorn Ljosa
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1

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....

Shashank Agarwal
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i am using this regex : :) ( its translated ABNF ) 

[a-zA-Z]([a-zA-Z]|[0-9]|\+|\-|\.)*:\/\/((([a-zA-Z]|[0-9]|-|\.|_|~)|%[0-9A-Fa-f][0-9A-Fa-f]|[!$&'\(\)\*\+,;=]|:)*@)?(\[((([0-9A-Fa-f]{1,4}:){6}([0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9]))|::([0-9A-Fa-f]{1,4}:){5}([0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9]))|([0-9A-Fa-f]{1,4})?::([0-9A-Fa-f]{1,4}:){4}([0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9]))|(([0-9A-Fa-f]{1,4}:){0,1}[0-9A-Fa-f]{1,4})?::([0-9A-Fa-f]{1,4}:){3}([0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9]))|(([0-9A-Fa-f]{1,4}:){0,2}[0-9A-Fa-f]{1,4})?::([0-9A-Fa-f]{1,4}:){2}([0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9]))|(([0-9A-Fa-f]{1,4}:){0,3}[0-9A-Fa-f]{1,4})?::[0-9A-Fa-f]{1,4}:([0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9]))|(([0-9A-Fa-f]{1,4}:){0,4}[0-9A-Fa-f]{1,4})?::([0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9]))|(([0-9A-Fa-f]{1,4}:){0,5}[0-9A-Fa-f]{1,4})?::[0-9A-Fa-f]{1,4}|(([0-9A-Fa-f]{1,4}:){0,6}[0-9A-Fa-f]{1,4})?::)|v[0-9A-Fa-f]\.(([a-zA-Z]|[0-9]|-|\.|_|~)|[!$&'\(\)\*\+,;=]|:))\]|(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])|(([a-zA-Z]|[0-9]|-|\.|_|~)|%[0-9A-Fa-f][0-9A-Fa-f]|[!$&'\(\)\*\+,;=])*)(:[0-9]*)?(((\/(([a-zA-Z]|[0-9]|-|\.|_|~)|%[0-9A-Fa-f][0-9A-Fa-f]|[!$&'\(\)\*\+,;=]|:|@)*)*|\/((([a-zA-Z]|[0-9]|-|\.|_|~)|%[0-9A-Fa-f][0-9A-Fa-f]|[!$&'\(\)\*\+,;=]|:|@){1}(\/(([a-zA-Z]|[0-9]|-|\.|_|~)|%[0-9A-Fa-f][0-9A-Fa-f]|[!$&'\(\)\*\+,;=]|:|@)*)*)?|(([a-zA-Z]|[0-9]|-|\.|_|~)|%[0-9A-Fa-f][0-9A-Fa-f]|[!$&'\(\)\*\+,;=]|:|@){1}(\/(([a-zA-Z]|[0-9]|-|\.|_|~)|%[0-9A-Fa-f][0-9A-Fa-f]|[!$&'\(\)\*\+,;=]|:|@)*)*|(([a-zA-Z]|[0-9]|-|\.|_|~)|%[0-9A-Fa-f][0-9A-Fa-f]|[!$&'\(\)\*\+,;=]|@){1}(\/(([a-zA-Z]|[0-9]|-|\.|_|~)|%[0-9A-Fa-f][0-9A-Fa-f]|[!$&'\(\)\*\+,;=]|:|@)*)*))?\/?(\?((([a-zA-Z]|[0-9]|-|\.|_|~)|%[0-9A-Fa-f][0-9A-Fa-f]|[!$&'\(\)\*\+,;=]|:|@)|\/|\?)*)?(\#((([a-zA-Z]|[0-9]|-|\.|_|~)|%[0-9A-Fa-f][0-9A-Fa-f]|[!$&'\(\)\*\+,;=]|:|@)|\/|\?)*)?
Pavel Perna
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You can use the following regex expression for extracting any type of url coming in message.

String regex = "(http(s)?:\/\/.)?(www\.)?[-a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]{2,6}\b([-a-zA-Z0-9@:%_\+.~#?&/=]*)";
Thomas Ayoub
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The90sArtist
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Typescript/Angular

This works for me:

const regExpressionUrl = new RegExp(/(https?:\/\/[^\s]+)/g); //detect URL

Ref: https://www.regextester.com/96249%7CRegular

Sampath
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