calc if rx stats by shell script.

gistfile1.txt

ifname=$1

let bytes1=0
while true; do
        let bytes2=`ip -s link  show $ifname  | grep -A 1 RX | grep -v RX | awk '{print $1}'`
        let diff=(bytes2 - bytes1)
        let diff=(diff / 1024 / 1024)
        echo "bandwitdth is $diff Mbps"
        let bytes1=bytes2
        sleep 1
done