$re = '/http:\/\/(www\.[a-z0-9]+([\-\.][a-z0-9]+)*\.[a-z]{2,5})(:[0-9]{1,5})?(\/.*)?$|^(\/.*)/m';
$str = 'http://www.google.com
/~germain/CS4480
http://www.cs.utah.edu/~germain/CS4480 HTTP/1.1
http://www.cs.utah.edu/~germain/CS4480:8080 HTTP/1.1
http://www.cs.utah.edu:8080/~germain/CS4480
http://www.cs.utah.edu/~germain/CS4480';
preg_match_all($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