shell应用：监控下载速度

事例：

#!/bin/bash # author: madding.lip # date: 2009.10.08 echo -n "请输入需要查询的网卡的接口:" read eth echo "你要查询的网卡接口为"$eth echo -n "输入需要等到的时间(秒):" read sec echo "你计算的是"$sec"秒内的平均流量" infirst=$(awk '/'$eth'/{print $1 }' /proc/net/dev |sed 's/'$eth'://') outfirst=$(awk '/'$eth'/{print $10 }' /proc/net/dev) sumfirst=$(($infirst+$outfirst)) sleep $sec"s" inend=$(awk '/'$eth'/{print $1 }' /proc/net/dev |sed 's/'$eth'://') outend=$(awk '/'$eth'/{print $10 }' /proc/net/dev) sumend=$(($inend+$outend)) sum=$(($sumend-$sumfirst)) echo $sec"秒内总流量为:"$sum"bytes" aver=$(($sum/$sec)) echo "平均流量为:"$aver"bytes/sec"