$re = '/@(\w+)/is';
$str = '[quote]
@lalalala
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras viverra ornare lectus sit amet dignissim. Vestibulum a mi leo. Nunc placerat accumsan elit, nec luctus ante malesuada sed. Quisque at urna non erat suscipit pharetra.
[/quote]
Morbi massa mauris, consequat vitae sem eu, maximus posuere ligula. Fusce pretium ultricies lectus sit amet bibendum. Aliquam nec dolor urna.';
preg_match_all($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