Apache正则表达式反向引用在httpd 2.4中无法访问？

I Love the new apache httpd 2.4 with lots of new cool stuff !

我喜欢新的apache httpd 2.4，有很多新的酷东西！

ap_expr is one of these new very promising features,

ap_expr是这些新的非常有前途的功能之一，

..BUT the following SSI snippet don't work as expected:

..但是以下SSI代码段不能按预期工作：

{{if expr="v('HTTP_SESSION') =~ /-user=([^&]+)/"}} 
{{set var="user" value="$1"}} 
{{endif}}

The if is working BUT the var isn't set ! This doesn't make any sense.

if是工作但是没有设置var！这没有任何意义。

error.log says:

error.log说：

.. AH01330: regex capture $1 is out of range

The doc (http://httpd.apache.org/docs/2.4/expr.html#other) is confusing and have no samples anywhere near.

doc（http://httpd.apache.org/docs/2.4/expr.html#other）令人困惑，并且附近没有样本。

I know that there is a legacy (workaround) switch for SSI.. but I don't want to use it since old Start- and End-tags are forced Legacy

我知道SSI有一个遗留（变通方法）开关..但我不想使用它，因为旧的开始和结束标签是强制遗留的

Doing similar regex-parsing-tricks w SetEnvIfExpr is not helping either

做类似的正则表达式解析 - 技巧SetEnvIfExpr也没有帮助

3 个解决方案

#1

by changing

通过改变

{{if expr="v('HTTP_SESSION') =~ /-user=([^&]+)/"}} 
    {{set var="user" value="$1"}} 
{{endif}}

至

{{if expr="v('HTTP_SESSION') =~ /-user=([^&]+)/"}} 
    {{set var="user" value="$0"}}
    {{if expr="v('user') =~ /([^&]+)$/"}}
         {{set var="user" value="$0"}}
    {{endif}}
{{endif}}

one can work around the problem using the fact that $0 seems to work

使用$ 0似乎可行的事实可以解决问题

#2

According to the documentation:

根据文件：

Regular expression backreferences The strings $0 ... $9 allow to reference the capture groups from a previously executed, successfully matching regular expressions. They can normally only be used in the same expression as the matching regex, but some modules allow special uses.

正则表达式反向引用字符串$ 0 ... $ 9允许从先前执行的，成功匹配的正则表达式引用捕获组。它们通常只能在与匹配的正则表达式相同的表达式中使用，但某些模块允许特殊用途。

You are using a capturing group and you are referencing that using index 1, this should be ok using a standard regex engine, but according to the documentation you can reference from $0...$9. I guess apache is filling the inde 0 with your capturing group instead of 1 and that's you get the regex capture $1 is out of range

您正在使用捕获组，并且您使用索引1引用它，使用标准正则表达式引擎应该没问题，但根据文档，您可以引用$ 0 ... $ 9。我猜apache正在用你的捕获组填充inde 0而不是1，这就是你得到正则表达式捕获$ 1超出范围

Change the index $1 to $0 by using:

使用以下命令将索引$ 1更改为$ 0：

{{if expr="v('HTTP_SESSION') =~ /-user=([^&]+)/"}} 
{{set var="user" value="$0"}} 
{{endif}}

#3

{{if expr="v('HTTP_SESSION') =~ /-user=([^&]+)/ && $1 =~ /(.+)/"}} 
    {{set var="user" value="$0"}} 
{{endif}}

#1