[SOLVED] How to extract a specific character inside a parentheses using sed command?

Issue

I want to extract an atomic symbols inside a parentheses using sed.

The data I have is in the form C(X12), and I only want the X symbol

EX: that a test command :

echo "C(Br12)" | sed 's/[0-9][0-9])$//g'

gives me C(Br.

Solution

You can use

sed -n 's/.*(\(.*\)[0-9]\{2\})$/\1/p'

See the online demo:

sed -n 's/.*(\(.*\)[0-9]\{2\})$/\1/p' <<< "c(Br12)"
# => Br

Details

• -n - suppresses the default line output
• .*(\(.*\)[0-9]\{2\})$ - a regex that matches
  • .* - any text
  • ( - a ( char
  • \(.*\) - Capturing group 1: any text up to the last....
  • [0-9]\{2\} - two digits
  • )$ - a ) at the end of string
• \1 - replaces with Group 1 value
• p - prints the result of the substitution.

Answered By - Wiktor Stribiżew

Answer Checked By - Robin (WPSolving Admin)