CODEWITHSUNDEEP
regexlinuxsed
Iliass Mw
Iliass Mw

Reputation: 69

place a comma before a bracket with sed

I have a text formatted like following:

key [value]
key [value, value]

now I realized I forgot to put a comma between the key and the values array, which means I am trying to get this:

key, [value]
key, [value, value]

I thought, instead of regenerating the file which takes several hours, I could maybe easily do it with sed. I tried cat small.txt | sed -n 's/{ \[}/{, \[}/g' and some other variants (like without {} and without spaces, I get no error, but the file doesn't change

Upvotes: 2

Views: 206

Answers (1)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626738

You may use

sed -E 's/([[:alnum:]])([[:space:]]+\[)/\1,\2/g' small.txt > newsmall.txt

Here, -E enables the POSIX ERE regex engine and the command does the following:

  • ([[:alnum:]])([[:space:]]+\[) finds an alphanumeric and places it in Group 1, then grabs 1+ whitespaces and a [ into Group 2
  • \1,\2 - replaces the match with Group 1, then , and then Group 2 contents.

If you want to modify the file inplace, see sed edit file in place.

Upvotes: 1

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