How to select section in regular expression in linux commands

Question

I have these lines that every line begin a word then equal and several sentence so I like select every section. For example:

      delete = \account
          user\
          admin
           admin right is good.
      add = \
          nothing
          no out
          input output is not good 
      edit = permission 
          bob
          admin
          alice killed bob!!!

I want to select a section for example:

  add = \
      nothing
      no out
      input output is not good

I like do it with regular expression.

score 0 · Answer 1 · answered Oct 26 '16 at 13:18

0

Your question is a bit vague but you could try the following ...

/\s*(\w+) = ([^=]*\n)*/m

... subject to the requirement that the last section is terminated with \n.

this works by:

'\s*' matching some optional leading whitespace
'(\w+)' capturing the name of the section
' = ' matches the space equals space separator
'([^=]*\n)' it then captures a string that does not include an equals and ends with a newline
'*' and it does that last bit multiple times

The m flag is then required to set multi-line.

See the following to quickly see the groups that are output for each match ...

https://regex101.com/r/oDKSy9/1

(NOTE: The g flag will probably not be required depending on how you use the regex.)

answered Oct 26 '16 at 13:18

haggisandchips

523
2
11

Thanks. Can you write this regular expression with sed command? – user6920966 Oct 29 '16 at 06:31
For example, replace add section with new value or delete them. – user6920966 Oct 29 '16 at 06:42
I find this solution: sed ':a;N;$!ba;s/$add =\([^=]*\n$*\)/stringReplace/g' fileName – user6920966 Oct 29 '16 at 07:27

score 0 · Answer 2 · answered Aug 20 '17 at 03:34

0

Solution by OP.

I find this solution:

csplit -k fileName '/.*=/' '{*}'

Thanks @haggisandchips

answered Aug 20 '17 at 03:34

Cœur

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How to select section in regular expression in linux commands

2 Answers2