<?php
$fp = fopen("log.txt","a ");
fwrite($fp,date("Y-m-d H:i:s"));
fwrite($fp," ");
fwrite($fp,$_SERVER[REMOTE_ADDR]);
fwrite($fp," ");
fwrite($fp,$_SERVER[HTTP_X_REWRITE_URL]);
fwrite($fp," ");
fwrite($fp,$_SERVER[HTTP_USER_AGENT]);
fwrite($fp," ");
fwrite($fp,$_SERVER["HTTP_REFERER"]);
fwrite($fp," ");
fclose($fp); 
?>这个是记录访问者ip的。怎么让写在txt里面换行啊,这是在一行显示的