删除一个文件或清空一个文件夹

function delfile($filename)
{
    if (!file_exists($filename)) {
        return;
    }

    if (!is_dir($filename)) {
        unlink($filename);
        return;
    }

    if (($handle = opendir($filename))) {
        while (($item = readdir($handle))) {
            if ($item != "." && $item != "..") {
                $fullpath = $filename . '/' . $item;
                if (!file_exists($fullpath)) {
                    continue;
                }

                if (is_dir($fullpath)) {
                    delfile($fullpath);
                    rmdir($fullpath);
                } else {
                    unlink($fullpath);
                }
            }
        }
        closedir($handle);
    }
}