RewriteCond 内的 %N 反向引用 [英] %N backreference inside RewriteCond

问题描述

我正在研究一个虚拟域系统.我有一个通配符 DNS 设置为 *.loc，我正在尝试处理我的 .htaccess 文件.以下代码有效:

I'm working on a virtual domain system. I have a wildcard DNS set up as *.loc, and I'm trying to work on my .htaccess file. The following code works:

RewriteEngine On
RewriteCond %{HTTP_HOST} ^(www.)?example\.loc$ [NC]
RewriteCond %{REQUEST_URI} !^/example/
RewriteRule (.*) /example/$1 [L,QSA]

但是，我希望它适用于我输入的任何内容.但是，我需要根据作为域找到的文本检查 %{REQUEST_URI}.我尝试使用此代码:

But, I want this to work with anything I put in. However, I need the %{REQUEST_URI} checked against the text found as the domain. I tried using this code:

RewriteEngine On
RewriteCond %{HTTP_HOST} ^(www.)?([a-zA-Z0-9-]*.)?([a-zA-Z0-9-]+)\.loc$ [NC]
RewriteCond %{REQUEST_URI} !^/%3/
RewriteRule (.*) /%3/$1 [L,QSA]

但是行 RewriteCond %{REQUEST_URI} !^/%3/ 导致我的代码抛出内部服务器错误.我知道这是因为我的代码中的 %N 但有没有办法使用它?我需要这一行，否则我的代码会因内部重定向而失败.

But the line RewriteCond %{REQUEST_URI} !^/%3/ causes my code to throw an Internal Server Error. I understand this is because of the %N in my code but is there a way I can work with it? I need this line, otherwise, my code fails from internal redirects.

我希望这对某人有意义.我所需要的只是能够在随后的 RewriteCond 中反向引用 RewriteCond.

I hope this makes sense to someone. All I need is to be able to backreference a RewriteCond in a following RewriteCond.

推荐答案

您在这里做错了 2 件事.

There's 2 things that you are doing wrong here.

首先，你的 %{HTTP_HOST} 正则表达式不好.您需要对 . 点进行转义，否则它们将被视为任何不是换行符的字符".这基本上使 %3 反向引用成为 TLD 之前主机名的最后一个字符(例如 http://blah.bar.loc、%3 = r).

First, your %{HTTP_HOST} regex is no good. You need to escape the . dots otherwise they'll be treated as "any character that's not a newline". This essentially makes the %3 backreference the last character of the hostname before the TLD (e.g. http://blah.bar.loc, %3 = r).

第二，您不能在 RewriteCond 的正则表达式中使用反向引用，只能使用左侧字符串，这是一种奇怪的限制.但是，您可以在正则表达式中使用 \1 引用，这样您就可以构造一个巧妙的左侧字符串来匹配.类似于 %3::%{REQUEST_URI} 然后你可以这样匹配:!^(.*?)::/\1/?.这个正则表达式本质上是说:在 :: 之前匹配和分组第一个文本块，然后确保 :: 之后的文本块> 以 /(first block)" 开头.

Second, you can't use backreferences in the regex of a RewriteCond, only the left side string, it's sort of a weird limitation. However, you can use the \1 references, in the regex so that you can construct a clever left side string to match against. Something like %3::%{REQUEST_URI} and then you can match like this: !^(.*?)::/\1/?. This regex essentially says: "match and group the first block of text before the ::, then make sure the block of text following the :: starts with /(first block)".

所以你的规则应该是这样的:

So your rules should look like this:

RewriteEngine On
RewriteCond %{HTTP_HOST} ^(www\.)?([a-zA-Z0-9-]*\.)?([a-zA-Z0-9-]+)\.loc$ [NC]
RewriteCond %3::%{REQUEST_URI} !^(.*?)::/\1/?
RewriteRule (.*) /%3/$1 [L,QSA]

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