Question

How do I grep and show the preceding and following 5 lines surrounding each matched line?

Answer 1

For BSD or GNU grep you can use -B num to set how many lines before the match and -A num for the number of lines after the match.

grep -B 3 -A 2 foo README.txt 

If you want the same number of lines before and after you can use -C num.

grep -C 3 foo README.txt 

This will show 3 lines before and 3 lines after.