iis url-rewrite 中奇怪的正则表达式错误

Question

这是我的模式：

^(\w{2}-\w{2})/questions(?:/(\w+))?(?:/(\d+))?(?:/.*?)?$

这些是我正在测试的内容：

en-us/questions/ask
en-us/questions/newest/15
en-us/questions/12/just-a-text-to-be-ignored

完美运行，这里是演示：

https://regex101.com/r/yC3tI8/1

但以下重写规则：

<rule name="en-us questions" enabled="true" stopProcessing="true">
  <match url="^(\w{2}-\w{2})/questions(?:/(\w+))?(?:/(\d+))?(?:/.*?)?$" />
  <action type="Rewrite" url="/questions.aspx?lang={R:1}&amp;tab={R:2}&amp;pid={R:3}" />
</rule>

当我将 link en-us/questions/newest 重定向到：/questions.aspx?lang=en-us&tab=&pid=

这有什么问题吗？现在大约 5 个小时，我只是在复习同样的东西

Answer 1

请注意，您有三个延迟捕获：

(?:/(\w+))?
(?:/(\d+))?
(?:/.*?)?

asp.net's regex implementation 将 ? 解释为：

In addition to specifying that a given pattern may occur exactly 0 or 1 time, the ? character also forces a pattern or subpattern to match the minimal number of characters when it might match several in an input string.

所以 asp.net 没有为 1 分配任何字符，没有为 2 分配任何字符，并收集其余字符3.

要使用贪婪匹配而不是惰性匹配 ? 强制使用：{0,1}

所以你的正则表达式应该是这样的：

^(\w{2}-\w{2})/questions(?:/(\w+)){0,1}(?:/(\d+)){0,1}(?:/.*?)?$

Live example

Answer 2

由于您有三种可能的 url 结局最终会影响重写 url 的结果，您可以设置一个全面的规则希望匹配你想要的一切，或者你可以设置三个规则来相应地处理每个规则：

一条规则：

^(\w{2}-\w{2})/questions/(\w+)/?(\d+)?.*$

https://regex101.com/r/dN8bM9/1 - tries to handle all cases

<rule name="en-us questions" enabled="true" stopProcessing="true">
  <match url="^(\w{2}-\w{2})/questions/(\w+)/?(\d+)?.*$" />
  <action type="Rewrite" url="/questions.aspx?lang={R:1}&amp;tab={R:2}&amp;pid={R:3}" />
</rule>

_{* 注意：原始模式未能捕获第二组的一个可能原因是包含 (?:) - 这意味着匹配但不捕获；将其排除在外可能会解决那里的大部分问题。}

三个规则：

^(\w{2}-\w{2})/questions/(\w+)$

https://regex101.com/r/lI8bQ1/1 - en-us/questions/[single word]

^(\w{2}-\w{2})/questions/(\d+)/.*$

https://regex101.com/r/hV5fK3/1 - en-us/questions/[digits]/discard

^(\w{2}-\w{2})/questions/(\w+)/(\d+)$

https://regex101.com/r/kO0dJ0/1 - en-us/questions/[single word]/[digits]

将它们全部放入规则集中：

<rule name="en-us questions case one" enabled="true" stopProcessing="true">
  <match url="^(\w{2}-\w{2})/questions/(\w+)$" />
  <action type="Rewrite" url="/questions.aspx?lang={R:1}&amp;tab={R:2}" />
</rule>  
<rule name="en-us questions case two" enabled="true" stopProcessing="true">
  <match url="^(\w{2}-\w{2})/questions/(\d+)/.*$" />
  <action type="Rewrite" url="/questions.aspx?lang={R:1}&amp;tab={R:2}" />
</rule>  
<rule name="en-us questions case three" enabled="true" stopProcessing="true">
  <match url="^(\w{2}-\w{2})/questions/(\w+)/(\d+)$" />
  <action type="Rewrite" url="/questions.aspx?lang={R:1}&amp;tab={R:2}&amp;pid={R:3}" />
</rule>

_{* 注意：您可能需要以某种方式调整它，但它应该让您了解如何适应三种不同的变体（如您所见）来重写您的 urls.}

iis url-rewrite 中奇怪的正则表达式错误

Weird regex bug in iis url-rewrite

regex

asp.net

web-config

url-rewriting