Это проще
$str = '';
$isMatched = preg_match('/^^((https|http|ftp|rtsp|mms)?:\/\/)[^\s]+$/', $str, $matches);
var_dump($isMatched, $matches);Сопоставьте практически любой URL-адрес:
^((https?|ftp|news):\/\/)?([a-z]([a-z0-9\-]*[\.。])+([a-z]{2}|aero|arpa|biz|com|coop|edu|gov|info|int|jobs|mil|museum|name|nato|net|org|pro|travel)|(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]))(\/[a-z0-9_\-\.~]+)*(\/([a-z0-9_\-\.]*)(\?[a-z0-9+_\-\.%=&]*)?)?(#[a-z][a-z0-9_]*)?$ пример: