$re = '/\w+://\w+\.\w+\.\w+[^"]+/m';
$str = 'http://net.tutsplus.com/tutorials/other/8-regular-expressions-you-should-know/"
http://www.asecuritysite.com/content/icon_clown.gif" alt="if broken see alex@school.ac.uk +44(0)1314552759" height="100"
http://www.rottentomatoes.com/m/sleeper/"
http://www.rottentomatoes.com/m/sleeper/trailer/"
http://www.rottentomatoes.com/m/star_wars/"
http://www.rottentomatoes.com/m/star_wars/trailer/"
http://www.rottentomatoes.com/m/wargames/"
http://www.rottentomatoes.com/m/wargames/trailer/"
https://www.sans.org/press/sans-institute-and-crowdstrike-partner-to-offer-hacking-exposed-live-webinar-series.php"> SANS to Offer "Hacking Exposed Live"
https://www.sans.org/webcasts/archive/2013"';
preg_match_all($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