Apache rewrite 部分细节

多个.htaccess 匹配的优先级

网站根路径下有一个.htaccess ，根目录下的文件夹 test 中也有一个.htaccess ，那么，访问 http://localhost/test/xyz 会有什么结果呢（ test 下不存在名为 xyz 的文件），或者说如果两个.htaccess 都会对错误的访问进行处理，谁的优先级更高？

根路径下：

RewriteEngine On

RewriteCond %{REQUEST_FILENAME} -s [OR]

RewriteCond %{REQUEST_FILENAME} -l [OR]

RewriteCond %{REQUEST_FILENAME} -d

RewriteRule ^.*$ - [L]

RewriteRule ^.*$ https://baidu.com [R=301,L]

test 路径下：

RewriteEngine On

RewriteCond %{REQUEST_FILENAME} -s [OR]

RewriteCond %{REQUEST_FILENAME} -l [OR]

RewriteCond %{REQUEST_FILENAME} -d

RewriteRule ^.*$ - [L]

RewriteRule ^.*$ https://bing.com [R=301,L]

测试结果是 test 路径下的.htaccess 起效了，也就是在浏览器上访问 http://localhost/test/xyz 实际上跳转到了 Bing 。当我把 test 下的.htaccess 移除后则会跳转到 Baidu.

罗列一些细节

$N 匹配的是 RewriteRule 中正则匹配的内容(RewriteRule backreferences)，而%N 匹配的是 RewriteCond 中正则匹配的内容(RewriteCond backreferences)，而\N 则是正则表达式中原生的反向引用 有时候出现的::并不是特殊的符号，只是方便使用的分隔符而已，喜欢的话可以用##等替代 12 RewriteCond TestString CondPattern 中， TestString 可以是以下内容构成的:

RewriteRule backreferences

RewriteCond backreferences

RewriteMap expansions 3

Server-Variables 4

RewriteRule Pattern Substitution [flags]中， pattern 匹配的是什么？就我的理解来说，如果访问的链接是 http://localhost:80/test/hello/hahahaha?x=100 ，

如果它由网站根目录下的.htaccess 来处理，它匹配的内容就是 test/hello/hahahaha; 如果它由根目录 /test/.htaccess 来处理，它匹配的内容就是 hello/hahahaha

What is matched?5 In VirtualHost context, The Pattern will initially be matched against the part of the URL after the hostname and port, and before the query string (e.g. “/app1/index.html ”). In Directory and htaccess context, the Pattern will initially be matched against the filesystem path, after removing the prefix that led the server to the current RewriteRule (e.g. “ app1/index.html ” or “ index.html ” depending on where the directives are defined). If you wish to match against the hostname, port, or query string, use a RewriteCond with the %{HTTP_HOST}, %{SERVER_PORT}, or %{QUERY_STRING} variables respectively. In any case, remember that regular expressions are substring matches. That is, you don ’ t need the regex to describe the entire string, just the part that you wish to match. Thus, using a regex of . is often sufficient rather than .*, and the regex abc is not the same as ^abc$.

以后再补充。。。。。