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POThis regex matches and shouldn't. Why is it?
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copied!<p>This regex:</p> <blockquote> ^((https?|ftp)\:(\/\/)|(file\:\/{2,3}))?(((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3} (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))|(((([a-zA-Z0-9]+)(\.)?)+?)(\.)([a-z]{2} |com|org|net|gov|mil|biz|info|mobi|name|aero|jobs|museum))([a-zA-Z0-9\?\=\&\%\/]*)?$ </blockquote> <p>Formatted for readability:</p> <pre><code>^( # Begin regex / begin address clause (https?|ftp)\:(\/\/)|(file\:\/{2,3}))? # protocol ( # container for two address formats, more to come later ((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3} (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?) # match IP addresses )|( # delimiter for address formats ((([a-zA-Z0-9]+)(\.)?)+?) # match domains and any number of subdomains (\.) #dot for .com ([a-z]{2}|com|org|net|gov|mil|biz|info|mobi|name|aero|jobs|museum) #TLD clause ) # end address clause ([a-zA-Z0-9\?\=\&\%\/]*)? # querystring support, will pretty this up later $ </code></pre> <p>is matching:</p> <blockquote>www.google</blockquote> <p>and shouldn't be. This is one of my "fail" test cases. I have declared the TLD portion of the URL to be mandatory when matching on alpha instead of on IP, and "google" doesn't fit into the "[a-z]{2}" clause.</p> <p>Keep in mind I will fix the following issues seperately - this question is about why it matches www.google and shouldn't.</p> <ul> <li>Querystring needs to support proper formats only, currently accepts any combination of querystring characters</li> <li>Several protocols not supported, though the scope of my requirements may not include them</li> <li>uncommon TLDs with 3 characters not included</li> <li>Probably matches <a href="http://www.google..com" rel="nofollow noreferrer">http://www.google..com</a> - will check for consecutive dots</li> <li>Doesn't support decimal IP address formats</li> </ul> <p><strong>What's wrong with my regex?</strong></p> <p>edit: See also a previous problem with an earlier version of this regex on a different test case: <a href="https://stackoverflow.com/questions/1622446/how-can-i-make-this-regex-match-correctly">How can I make this regex match correctly?</a></p> <p><br /><br /> edit2: Fixed - The corrected regex (as asked) is:</p> <blockquote> ^((https?|ftp)\:(\/\/)|(file\:\/{2,3}))?(((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3} (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))|(((([a-zA-Z0-9]+)(\.)?)+?)(\.)([a-z]{2}|com|org|net|gov|mil|biz|info|mobi|name|aero|jobs|museum))([\/][\/a-zA-Z0-9\.]*)*?([\/]?[\?][a-zA-Z0-9\=\&\%\/]*)?$ </blockquote>

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