#!/usr/bin/env bash out="if (\$http_user_agent ~* \"" # loop lists for filename in ./lists/*.txt; do # line by line while read -r line; do # ignore empty [ -z "$line" ] && continue # ignore comments [[ $line =~ ^#.* ]] && continue # add to out out="$out$line|" done < $filename done out=${out::-1} out="$out\") {\n return 444;\n}\n" printf "$out"