iptables-list

#!/usr/bin/env bash

set -eu

if (( EUID )); then
    echo 'This script must be run with root privileges.' >&2
    exit 1
fi

prgname=${0##*/}

# ----------------------------------------

case $prgname in
    ip6*) prefix='ip6' ;;
    *) prefix='ip' ;;
esac

tables=("$@")
if (( ! ${#tables[@]} )); then
    src="/proc/net/${prefix}_tables_names"
    [[ -e $src ]] && readarray -t tables <"$src"
fi

for table in "${tables[@]}"; do
    echo $'\n--------------------------------------------------'
    printf '> %s table %s:\n\n' "$prefix" "$table"
    "${prefix}tables" -t "$table" -nvL
    echo
    "${prefix}tables" -t "$table" -S
done

echo