// TEST 1 - normal mode

$url = "screenshot: http://crazy-tronners.com/aarec/screenshot_68.png";
$regexp_url = "@([http:\/\/|HTTP:\/\/|https:\/\/|HTTPS:\/\/][a-zA-Z.0-9-]*[\/a-zA-Z.-_]*\/[\/a-zA-Z0-9%._-]*)@";

//1
echo preg_match($regexp_url, $url, $results);


// TEST 2 - multiline mode

$url = "

screenshot: http://crazy-tronners.com/aarec/screenshot_68.png

";
$regexp_url = "@^recording: ([http:\/\/|HTTP:\/\/|https:\/\/|HTTPS:\/\/][a-zA-Z.0-9-]*[\/a-zA-Z.-_]*\/[\/a-zA-Z0-9%._-]*)@m";

// 0 -- fails :/
echo preg_match($regexp_url, $url, $results);