Linux 监控每秒网卡流量

#! /bin/bash 
. ~/.bash_profile
#Author: Vogts WangTao 2008-12-18 
#Get summry info 
host2=` /sbin/ifconfig eth0 | grep inet | awk -F ':' '{print $2}' | awk '{print $1}'`
echo "Current Ip: "`/sbin/ifconfig eth0 | grep inet` 
echo "Summry info: "`/sbin/ifconfig eth0 | grep bytes` 
#sleep 1 second ,monitor eth0 
receive1=`cat /proc/net/dev|grep eth0 | awk '{print $1}'|sed -s 's/eth0://g'` 
receive_pack1=`cat /proc/net/dev|grep eth0 | awk '{print $2}'` 
send1=`cat /proc/net/dev|grep eth0 | awk '{print $9}'` 
send_pack1=`cat /proc/net/dev|grep eth0 | awk '{print $10}'` 
sleep 1 
receive2=`cat /proc/net/dev|grep eth0 | awk '{print $1}'|sed -s 's/eth0://g'` 
receive_pack2=`cat /proc/net/dev|grep eth0 | awk '{print $2}'` 

receive_cnt=`expr $receive2 - $receive1` 
receive_pack_cnt=`expr $receive_pack2 - $receive_pack1` 

send2=`cat /proc/net/dev|grep eth0 | awk '{print $9}'` 
send_pack2=`cat /proc/net/dev|grep eth0 | awk '{print $10}'` 

send_cnt=`expr $send2 - $send1` 
send_pack_cnt=`expr $send_pack2 - $send_pack1` 

num1=`expr  $receive_cnt / 1024`
num2=`expr  $receive_pack_cnt / 1024`
num3=`expr  $send_cnt / 1024`
num4=`expr  $send_pack_cnt / 1024`
echo 'eth0 Receive KBytes:' $num1 ' Packets:' $num2
echo 'eth0 Send KBytes:' $num3 ' Packets:' $num4
if [ "$num1" -gt 200 ]
   then
   smail.pl "$host2-eth0 receive_cnt is ${num1}kb"
fi

if [ "$num3" -gt 200 ]
   then
   smail.pl "$host2-eth0 send_cnt is ${num3}kb"
fi