$re = '/product: ([\w ]+)(?:version: ([\w.]+)| \w+:)/mi';
$str = 'ftp (product: vsftpd version: 2.3.4 ostype: Unix)
product: Apache Jserv extrainfo: Protocol v1.';
preg_match_all($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