#!/bin/sh
#
# rule expire ó¸®
#
# - rule »ý¼º ¿¹) iptables -A INPUT -s <IP> -m comment --comment "expire=`date -d '+ 30 min' +%s`" -j DROP

export PATH=$PATH:/sbin:/usr/sbin:/usr/local/bin

iptables -L INPUT -n --line-numbers  | \
        perl -ne 'next unless /(^\d+).*expire=(\d+)/; if ($2 < time) { system "iptables -D INPUT $1"; }'