bash 如何处理grep中的括号？
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How to handle parenthesis in grep?
提问by Misha Moroshko
stris of the following pattern:
str是以下模式：
1 abc (1 <something>)
For example:
例如：
1 abc (1 hello)
1 abc (1 shalom)
1 abc (1 hola)
How could I extract <something>from strusing egrep?
我怎么<something>能从strusing 中提取egrep？
回答by mathematical.coffee
If you want to extract just the <something>then I'd suggest grep -P(perl regex):
如果你只想提取<something>然后我建议grep -P（perl regex）：
grep -P -o '(?<=\(1 ).*?(?=\))' INPUTFILE
The -oreturns just the matched portion being <something>. The regex looks for text preceded by (1and followed by ).
该-o返回刚刚匹配部分是<something>。正则表达式查找前面(1和后面的文本)。
You wouldn't be able to do that with egrepas it doesn't support lookarounds. The best you'd do is extract the (1 <something>)with:
您将无法做到这一点，egrep因为它不支持环视。你最好做的是提取(1 <something>)：
egrep -o '\(1 (.*)\)' INPUTFILE
[foo@bar ~]$ grep -P -o '(?<=\(1 ).*?(?=\))' INPUTFILE
hello
shalom
hola
[foo@bar ~]$ egrep -o '\(1 (.*)\)' INPUTFILE
(1 hello)
(1 shalom)
(1 hola)
回答by jaypal singh
Alternatively you can use a simple awkone-liner for this.
或者，您可以awk为此使用简单的单衬。
awk -F"[ )]" '{print $(NF-1)}' filename
Test:
测试：
[jaypal:~/Temp] cat filename
1 abc (1 hello)
1 abc (1 shalom)
1 abc (1 hola)
[jaypal:~/Temp] awk -F"[ )]" '{print $(NF-1)}' filename
hello
shalom
hola
