#!/bin/sh

showtime=20
filter=

if [ $# -gt 0 ]
then
	showtime=$1
	[ "$2" ] && {
		filter="grep \"$2\""
	}
else
	echo "Connection track will be shown $showtime seconds"
	echo "Run the script with an elapse time (seconds) argument"
	sleep 2
fi

if [ "$filter" ]
then
	cmd="cat /proc/net/ip_conntrack | $filter"
else
	cmd="cat /proc/net/ip_conntrack"
fi

for i in $showtime
do
	while [ $i -gt 0 ]
	do
		clear
		eval $cmd
		sleep 1
		i=`expr $i - 1`
	done
done

exit 0