I want to grep through logs, and gather a certain exception stacktrace but I want to only see those that do not contain certain keywords in --after-context. I do not know in which line in after-context the keyword is. Simple example - given this shell code: grep -A 2 A <<EOF A B C R A Z Z X EOF the output is: A B C -- A Z Z I'd like the output to be: A Z Z I want to exclude any match that has 'B' in after-context How do I do this? Using grep is not a requirement, though I only have access to coreutils and perl.