#!/bin/sh
#

CUMULATIVE=10
RXTX="RX"

cnt=0
rxbytescml=0
txbytescml=0
rxold=0
txold=0
rxbytes=0
txbytes=0
rxpeak=0
txpeak=0
INTERFACE=$1
while [ 1 ]; do 
	rxold=$rxbytes
	txold=$txbytes
	rxbytes=`ifconfig $INTERFACE |grep "$RXTX bytes" | tr -d " " |cut -f2 -d: | cut -f1 -d'('`
	txbytes=`ifconfig $INTERFACE |grep "$RXTX bytes" | tr -d " " |cut -f3 -d: | cut -f1 -d'('`
	if [ $rxold -eq 0 ]; then
		rxold=$rxbytes
	fi
	if [ $txold -eq 0 ]; then
		txold=$txbytes
	fi
	rxbytescml=$[rxbytescml+rxbytes-rxold]
	txbytescml=$[txbytescml+txbytes-txold]
	if [ $[rxbytes-rxold] -gt $rxpeak ]; then
		rxpeak=$[rxbytes-rxold]
	fi
	if [ $[txbytes-txold] -gt $txpeak ]; then
		txpeak=$[txbytes-txold]
	fi
	printf "\r                                                                         \r"
	printf "%s:                        RX:%s kbps, TX:%s kbps" \
		$INTERFACE \
		$[(rxbytes-rxold)*8/1024] \
		$[(txbytes-txold)*8/1024]
	sleep 1
	cnt=$[cnt+1]
	if [ $cnt -eq $CUMULATIVE ]; then
		time=`date +"%d.%m.-%H:%M:%S"`
		printf "\r%s: %s - %s secs avg: RX:%s kbps, TX:%s kbps, RX peak:%s kbps, TX peak:%s kbps\n" \
			$INTERFACE \
			$time \
			$CUMULATIVE \
			$[(rxbytescml/CUMULATIVE)*8/1024] \
			$[(txbytescml/CUMULATIVE)*8/1024] \
			$[rxpeak*8/1024] \
			$[txpeak*8/1024]
		rxbytescml=0
		txbytescml=0
		cnt=0
		rxpeak=0
		txpeak=0
	fi
done