public static function getFileNum($dir, $file_num = 0)
{
$resource = opendir($dir);
while ($filename = readdir($resource)) {
if ($filename != "." && $filename != "..") {
$path = "{$dir}/{$filename}";
if (is_dir($path)) {
// recursion
$file_num = self::getFileNum($path, $file_num);
} else {
$file_num++;
}
}
}
closedir($resource);
return $file_num;
}