Linux 在 bash 中使用 SED 打印 RegEx 匹配
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Print RegEx matches using SED in bash
提问by Matthew Warman
I have an XML file, the file is made up of one line.
我有一个 XML 文件，该文件由一行组成。
What I am trying to do is extract the "finalNumber" attribute value from the file via Putty. Rather than having to download a copy and search using notepad++.
我想要做的是finalNumber通过 Putty 从文件中提取“ ”属性值。而不必下载副本并使用记事本++进行搜索。
I've built up a regular expression that I've tested on an On-line Tool, and tried using it within a sedcommand to duplicate grep functionality. The command runs but doesn't return anything.
我已经建立了一个正则表达式，我已经在一个在线工具上测试过，并尝试在sed命令中使用它来复制 grep 功能。该命令运行但不返回任何内容。
RegEx:
正则表达式：
(?<=finalNumber=")(.*?)(?=")
sedCommand (returns nothing, expected 28, see file extract):
sed命令（不返回任何内容，预期为 28，请参阅文件摘录）：
sed -n '/(?<=finalNumber=")(.*?)(?=")/p' file.xml
File Extract:
文件提取：
...argo:finalizedDate="2012-02-09T00:00:00.000Z" argo:finalNumber="28" argo:revenueMonth=""...
I feel like I am close (i could be wrong), am I on the right lines or is there better way to achieve the output?
我觉得我很接近（我可能是错的），我是在正确的路线上还是有更好的方法来实现输出？
采纳答案by Perleone
Nothing wrong with good old grep here.
这里的老式 grep 没什么问题。
grep -E -o 'finalNumber="[0-9]+"' file.xml | grep -E -o '[0-9]+'
Use -Efor extended regular expressions, and -oto print only the matching part.
使用-E的扩展正则表达式，并-o只打印匹配的部分。
回答by choroba
seddoes not support look-ahead assertions. Perl does, though:
sed不支持前瞻断言。但是，Perl 确实如此：
perl -ne 'print if /(?<=finalNumber=")(.*?)(?=")/'
回答by Alexey Shumkin
As I understand, there is no need to use look-aheads here. Try this one
据我了解，这里没有必要使用前瞻。试试这个
sed -n '/finalNumber="[[:digit:]]\+"/p'
回答by potong
This might work for you (GNU sed):
这可能对你有用（GNU sed）：
sed -r 's/.*finalNumber="([^"]*)".*//' file
回答by texasbruce
Though you already select an answer, here is a way you can do in pure sed:
尽管您已经选择了一个答案，但您可以在纯 sed 中执行以下操作：
sed -n 's/^.*finalNumber="\([[:digit:]]\+\)".*$//p' <test
Output:
输出：
28
This replaces the entire line by the match number and print (because p will print the entire line so you have to replace the entire line)
这将用匹配号替换整行并打印（因为 p 将打印整行，因此您必须替换整行）
