// 追加内容
$file = fopen(dirname(dirname(__FILE__)).'/index.htm', 'r');
$content = fread($file, filesize(dirname(dirname(__FILE__)).'/index.htm'));
$hello = '' . PHP_EOL . $content;
fclose($file);
$file = fopen(dirname(dirname(__FILE__)).'/index.htm', 'w');
echo fwrite($file, $hello);
fclose($file);

现在上述代码是在html的第一行加了，请问，如果