$re = '/\([1-9]\d\)\s9?\d{4}-\d{4}/';
$str = '(11) 1111-1111 - fixo válido
(11) 11111-1111 - celular inválido
(11) 91111-1111 - celular válido
(11) 01111-1111 - celular inválido
(01) 91111-1111 - celular válido
';
preg_match_all($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