$re = '/[^.]*\.[^.]{2,3}(?:\.[^.]{2,3})?$/m';
$str = 'http://www.answers.com/article/1194427/8-habits-of-extraordinarily-likeable-people
http://www.apple.com
http://www.cnn.com.au
http://downloads.news.com.au
http://ftp.android.co.nz
http://global.news.ca
http://www.apple.com
';
preg_match_all($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