regular expression for web url

Question

I am using a regular expression for validation web url. that is not validating more than one dots(.) like www.gmail.....com, other than this it is working fine.can any body update my regular expression-

^[a-zA-Z0-9\-\.]+\.(com|org|net|mil|edu|COM|ORG|NET|MIL|EDU)$

URL's can contain a _lot_ of characters. Not only `a-z`. Characters like `ü` could appear, too. And you should match case-insensitive instead of using `com|COM` (think about `cOM` or `Com`, which are valid, too). — jwueller, Dec 13 '10 at 11:52
Your top-level domain part needs to account for the many country codes (.uk, .es, .us, .ca, .au and the 200-odd others) as well as other TLDs like .info, .tv, .museum... there are loads! You'd be best just using [a-z]{2,6} (as far as I know, no TLDs use numbers or other characters). — Nathan MacInnes, Dec 13 '10 at 12:07
@Nathan, there are a number of internationalized TLDs which include non-alpha characters: http://en.wikipedia.org/wiki/List_of_Internet_top-level_domains#Internationalized_country_code_top-level_domains — eyelidlessness, Dec 14 '10 at 05:51
@eyelidlessness, Oh yes, they came in recently didn't they. Well I have no idea how you check for them! — Nathan MacInnes, Dec 14 '10 at 08:37
@Nathan, you check for valid IRIs according to RFC 3987: http://stackoverflow.com/questions/161738/what-is-the-best-regular-expression-to-check-if-a-string-is-a-valid-url/190405#190405 — eyelidlessness, Dec 14 '10 at 16:55

El Ronnoco · Accepted Answer · 2010-12-13T11:57:13.300

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UPDATE. Note this is not foolproof by any means.

^([a-zA-Z0-9\-]+\.)+(com|org|net|mil|edu|COM|ORG|NET|MIL|EDU)$

The + tells the regex to match one or more times

edited Dec 13 '10 at 11:57

answered Dec 13 '10 at 11:51

El Ronnoco

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This doesn't take into account country codes, and the many other top-level domains. – Nathan MacInnes Dec 13 '10 at 11:53
I'm modifying the OPs regex to meet their stated requirements. – El Ronnoco Dec 13 '10 at 11:55
You are almost on to something. The first `\.` doesn't belong. – Marcelo Cantos Dec 13 '10 at 11:55
@Marcelo True, hadn't spotted that. It shouldn't have been there in the first place :) – El Ronnoco Dec 13 '10 at 11:58

Marcelo Cantos · Answer 2 · 2010-12-13T11:56:03.527

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For Perl-compatible regex syntax, you can do this:

^([a-zA-Z0-9-]|\.(?!\.))+\.(com|...

Also, this is very US-centric. My company's domain ends in .com.au.

edited Dec 13 '10 at 11:56

answered Dec 13 '10 at 11:50

Marcelo Cantos

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codevania · Answer 3 · 2010-12-14T05:29:35.957

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Why don't you use +? [\.]+ could be matched with one more .!

edited Dec 14 '10 at 05:29

answered Dec 13 '10 at 11:52

codevania

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regular expression for web url

3 Answers3