Question

Lets imagine I have a file with some lines and there is one line with this structure:

blah blah
YYYY      :['aaa','ddd']
blah
XXXX      :['member1', 'member2']
blah blah

I want to have a script to add member3 to the end of XXXX array automatically. I tried to use sed, but I do not know how to replace the last bracket of the lines started with XXXX with “‘member3’]”. So it looks like this:

blah blah
YYYY      :['aaa','ddd']
blah
XXXX      :['member1', 'member2', 'member3']
blah blah

Any help?

Answer 1

sed "/^XXXX /s/\]\$/, 'member3']/" < input

This applies a substitution to the lines that start with XXXX, replacing the final ] with 'member3']