$re = '/\broundcube.*?\bhttponly\b/i';
$str = 'roundcube_sessauth=-del-; expires=Thu, 06-Aug-2015 03:38:33 GMT; path=/; secure; httponly, roundcube_sessid=dh7a60r14c6qfa3lr7m90; path=/; secure; HttpOnly, roundcube_sessauth=S2124929b7486e6805d615a86; path=/; secure; httponly';
preg_match_all($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