【shell】实时查看网卡流量脚本

#!/bin/bash
eth0=$1
echo  -e    "流量进入--流量传出    "
while true; do
    old_in=$(cat /proc/net/dev |grep $eth0 |awk '{print $2}')
    old_out=$(cat /proc/net/dev |grep $eth0 |awk '{print $10}')
    sleep 1
    new_in=$(cat /proc/net/dev |grep $eth0 |awk '{print $2}')
    new_out=$(cat /proc/net/dev |grep $eth0 |awk '{print $10}')
    in=$(printf "%.1f%s" "$((($new_in-$old_in)/1024))" "KB/s")
    out=$(printf "%.1f%s" "$((($new_out-$old_out)/1024))" "KB/s")
    echo "$in $out"
done