#! /bin/sh
#
# net.sh
# Copyright (C) 2019 light <light@light-laptop>
#
# Distributed under terms of the MIT license.
#


LANG=""
while true
do
    up_time1=`ifconfig $1 | grep "bytes" | awk '{print $6}'`
    down_time1=`ifconfig $1 | grep "bytes" | awk '{print $2}'`

    sleep 1
    clear

    up_time2=`ifconfig $1 | grep "bytes" | awk '{print $6}'`
    down_time2=`ifconfig $1 | grep "bytes" | awk '{print $2}'`

    up_time1=${up_time1}
    up_time2=${up_time2}
    down_time1=${down_time1}
    down_time2=${down_time2}

    up_time=`expr $up_time2 - $up_time1`
    down_time=`expr $down_time2 - $down_time1`
    up_time=`expr $up_time / 1024`
    down_time=`expr $down_time / 1024`

    echo 上传速度: $up_time kb/s
    echo 下载速度: $down_time kb/s
done