#!/bin/bash
statnow(){
	for N in $INTERFACES
	do
		echo $N $(ifconfig $N |
			grep bytes |
			sed -e 's/([^()]*)//g' |
			tr -dc '[^ 0-9]')
	done
}
result(){
	echo "$1" $(($7-$4)) bits/sec '          '
}
go(){
	sleep 8
	S2="$(statnow)"
	for N in $INTERFACES
	do
		A=$(echo "$S1" | grep $N)
		B=$(echo "$S2" | grep $N)
		result "$(printf "%-5s" $N)Upstream:" $A $B
		result '   Downstream:' X $A $B
	done
}
INTERFACES=$(ifconfig -a|cut -f1 -d' ')
S1="$(statnow)"
if echo "$@" | grep -q f
then
	while true
	do
		go
		echo ''
		S1=$S2
	done
else
	go
fi