$re = '`:-.*?-:\W*(*SKIP)(*F)|(?:(?:http|ftp|https)://)?[\w-]+(?:\.[\w-]+)+([\w.,@?^=%&:/~+#-]*[\w@?^=%&\/~+#-])?`';
$str = ':-:casperon.png:-: google.com www.yahoo.com :-:sample.jpg:-: http://stackoverflow.com';
preg_match_all($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