netspeed.sh

    #!/bin/bash

    INTERVAL="1"  # update interval in seconds

     

    if [ -z "$1" ]; then

            echo

            echo usage: $0 [network-interface]

            echo

            echo e.g. $0 eth0

            echo

            exit

    fi

     

    IF=$1

     

    while true

    do

            R1=`cat /sys/class/net/$1/statistics/rx_bytes`

            T1=`cat /sys/class/net/$1/statistics/tx_bytes`

            sleep $INTERVAL

            R2=`cat /sys/class/net/$1/statistics/rx_bytes`

            T2=`cat /sys/class/net/$1/statistics/tx_bytes`

            TBPS=`expr $T2 - $T1`

            RBPS=`expr $R2 - $R1`

            TKBPS=`expr $TBPS / 1024`

            RKBPS=`expr $RBPS / 1024`

            echo "TX $1: $TKBPS kb/s RX $1: $RKBPS kb/s"

    done