Dead-simple awk log file for regex match, and write new file with results. Probably doesn't deserve a gist, but I like gisting.

awk-to-file.sh

#!/usr/bin/env bash

# example: awk a clamav logfile (clamout.log) and write new file(awklog.txt) of lines that have "Empty file"[case-sensitive] in them
awk '/Empty file/{ print $0 }' clamout.log.txt > awklog.txt