#!/usr/bin/env bash checkForRules() { # check if a Block states at least 1 reference (ufw blocks) # and has more 2 lines (Input, Output, Forward blocks) $1 -L | awk -v RS="\n\n" '$0 !~ /\(0 references\)/ && $0 ~ /.+\n.+\n.+/ {print $0}' } [[ -n "$(checkForRules ip6tables)" || -n "$(checkForRules iptables)" ]] && exit 1 exit 0