由网友(倒转流年、只为一眼红颜)分享简介：我知道，我们可以很容易地基地的RewriteCond任何HTTP 请求头。但是，我们检查（部分）在响应发送标头打算？特别是，在上次修改吗？I know that we can easily base a RewriteCond on any http request header. But can we check...

我知道，我们可以很容易地基地的RewriteCond任何HTTP 请求头。但是，我们检查（部分）在响应发送标头打算？特别是，在上次修改吗？

I know that we can easily base a RewriteCond on any http request header. But can we check (some of) the response headers that are going to be sent? In particular, the Last-modified one?

我想重写URL只在最后修改日期是早于30分钟，我想，以避免委托，办理入住手续的PHP文件，每一次从该目录中的文件的开销请求。

I want to rewrite a url only when the Last-modified date is older than 30 minutes and I'm trying to avoid the overhead of delegating that check to a php file every single time a file from that directory is requested.

在此先感谢！

推荐答案

出站头不存在，直到多晚于的mod_rewrite 行事。目前也没有任何文件修改时间检查功能内置到的mod_rewrite ，所以你开始使用它制作的的外部重写程序的品种，以找出是否有问题的文件已被修改RewriteMap指令。

The outbound headers do not exist until much later than mod_rewrite is acting. There also isn't any file-modification-time checking functionality built into mod_rewrite, so the closest you'd get using it is making a RewriteMap of the External Rewriting Program variety to find out whether the file in question has been modified.

如果我正确理解你的应用程序，你也可以考虑其在该目录中存储时间超过30分钟cron作业删除文件，然后重写一个文件不存在的条件。

If I understand your application correctly, you could also look into having a cron job delete files in that directory that are older than 30 minutes, and then rewriting on a file-nonexistence condition.