$re = '/https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]{2,6}\b([-a-zA-Z0-9@:%_\+.~#()?&//=]*)/mi';
$str = 'http://foo.com/blah_blah
http://foo.com/blah_blah/
http://foo.com/blah_blah_(wikipedia)
http://www.example.com/wpstyle/?p=364
https://www.example.com/foo/?bar=baz&inga=42&quux
http://userid:password@example.com:8080
http://foo.com/blah_(wikipedia)#cite-1
www.google.com
http://../
http:// shouldfail.com
http://224.1.1.1
http://142.42.1.1:8080/
ftp://foo.bar/baz
http://1337.net
http://foo.bar/?q=Test%20URL-encoded%20stuff
http://code.google.com/events/#&product=browser';
preg_match_all($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