$re = '/https?:\/\/(?:w{1,3}\.)?[^\s.]*(?:\.[a-z]+)+(?::\d+)?(?![^<]*(?:<\/\w+>|\/?>))/m';
$str = 'This is my text to be parsed which contains url
http://someurl.com <a href="http://thisshouldnotbetampered.com">
some text and a url http://someotherurl.com test 1q2w </a> <img src="http://someasseturl.com/abc.jpeg"/>
Hello http://someurl.com</a> <!-- fail -->
<img src="http://someurl.com/image.jpg>
http://someurl.localhost.com
<div>Regex is awesome</div>
<a href=\'https://help.mojohelpdesk.com/mytickets/show/26737327\'>https://help.mojohelpdesk.com/mytickets/show/26737327</a>
<a href="https://help.mojohelpdesk.com/mytickets/show/26737327">https://help.mojohelpdesk.com/mytickets/show/26737327</a>
https://google.com
https://www.mojo.com
http://localhost:3000
http://site.quelqu
http://localhost.com:3000
www.google.com';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php