$re = '/\[(data-user="\d+")\h+(data-userId="\d+")\]\s*(.+?)\s*\[\/\](.*)/s';
$str = '[data-user="12345" data-userId="678910"]
John Smith
[/]';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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