如何从readdir中排除隐藏的文件夹和文件？

$files = readdir('/path/to/folder');
$files = array_filter($files, create_function('$a','return ($a[0]!=".");'));

$ignoreList = array('cgi-bin', '.', '..', '._');
   if ($directory = opendir(APPPATH . 'controllers/user')) {
  while (false !== ($filename = readdir($directory))) {
    if (!in_array($filename, $ignoreList) and substr($filename, 0, 1) != '.') {
         echo $filename."<br>";
      }
   }
 }

$dir    = '/Users/Umesh/Sites/';
$files = preg_grep('/^([^.])/', scandir($dir));

print_r($files);

?>