Remove all lines except matching pattern line best practice (sed)

Question

I want to remove all lines except the line(s) containing matching pattern.

This is how I did it:

sed -n \'s/matchingpattern/matchingpattern/p\' file.         


        

Answer 1

This might work for you:

sed -n '/matchingpattern/p' file.txt

/.../ is an address which may have actions attached in this case p.