html - 从单行输出中删除 html/xml 的最简单方法

Question

我正在尝试清理 grep 的输出，如下所示:

<words>Http://www.path.com/words</words>

我试过使用...

sed 's/<.*>//' 

...删除标签，但这只会破坏整行。我不确定为什么会这样，因为每个“<”在到达内容之前都以“>”结束。

最简单的方法是什么？

谢谢!

Answer 1

为你的 sed 表达式试试这个:

sed 's/<.*>\(.*\)<\/.*>/\1/'

表达式的快速分解:

<.*>   - Match the first tag
\(.*\) - Match and save the text between the tags   
<\/.*> - Match the end tag making sure to escape the / character  
\1     - Output the result of the first saved match 
       -   (the text that is matched between \( and \))

---

更多关于反向引用

评论中出现了一个问题，为了完整性可能应该解决。

\( 和 \) 是 Sed 的反向引用标记。他们保存一部分匹配的表达式供以后使用。

例如，如果我们有一个输入字符串:

This has (parens) in it. In addition we can use parenslike thisparens using back-references.

我们开发一个表达式:

sed s/.*(\(.*\)).*\1\\(.*\)\1.*/\1 \2/

这给了我们:

parens like this

这到底是怎么回事？让我们分解这个表达式来找出答案。

表达式分割:

sed s/ - This is the opening tag to a sed expression.
.*     - Match any character to start (as well as nothing).
(      - Match a literal left parenthesis character.
\(.*\) - Match any character and save as a back-reference. In this case it will match anything between the first open and last close parenthesis in the expression.
)      - Match a literal right parenthesis character.
.*     - Same as above.
\1     - Match the first saved back-reference. In the case of our sample this is filled in with `parens`
\(.*\) - Same as above.
\1     - Same as above.
/      - End of the match expression. Signals transition to the output expression.
\1 \2  - Print our two back-references.
/      - End of output expression.

正如我们所见，从括号 (( 和 )) 之间获取的反向引用被替换回匹配表达式，以便能够匹配字符串parens.