監控linux流量shell版

想要實時查看linux流量情況，又不想再去下第三方工具，可以直接寫腳步運行！   系統:centos 6.5   原理：從/proc/net/dev中獲取到流量情況，再通過換算並除以間隔時間來得到流量單位M  

#------------------
#Author:Administrator
#Created:2015-04-10
#------------------
#!/bin/bash

#使用方法
usage()
{
  echo "useage: $0 ethname intervel"
  exit 0
}

#網口配置
if [ $# -gt 1 ];then
  ethname=$1
  num=`ifconfig|grep ${ethname}|wc -l`
  if [ $num -gt 0 ];then
   ethname=$1
  else
    echo "Can't find $ethname,Please Check"
    exit 1
  fi
fi

#時間配置
intervel=1
if [ $# -gt 0 ]; then
  interval=$2
  test=`expr "$interval" \* 0`
  if [ "$test" != "0" ]; then 
        echo "Invalid <interval> param '$interval' . It should be a integer number. Usage: $0 ethname intervel"
        exit -1  
  fi
  if [ $interval -lt 1 ]; then
        echo "Invalid <interval> param '$interval' . It should be > 0 (seconds). Usage: $0 ethname intervel"
        exit -1
  fi
fi

#函數判斷
if [ $# -ne 2 ]
then
 usage
fi

echo "$0 is starting,Device is $1,Intervel is $2"
echo -e "\n"

typeset Rev old_Rev

eth=$1
intervel=$2

old_Rev=`cat /proc/net/dev|grep $eth| awk '{print $1}'| awk -F : '{print $2}'`
old_Send=`cat /proc/net/dev|grep $eth|awk '{print $9}'`
#echo "old_Rev is $old_Rev"
#echo "Old_send is $old_Send"

while true
 do
 sleep $intervel

 Rev=`cat /proc/net/dev|grep $eth|awk '{print $1}'|awk -F : '{print $2}'`
 Send=`cat /proc/net/dev|grep $eth|awk '{print $9}'`
#echo "Rev is $Rev"
#echo "Send is $Send"

 diff_1=`awk -v Rev=$Rev -v old_Rev=$old_Rev -v intervel=$intervel 'BEGIN{printf "Receive is %6.2f", ( Rev - old_Rev ) / 1024 / 1024 / intervel * 8}'`

 diff_2=`awk -v Send=$Send -v old_Send=$old_Send -v intervel=$intervel 'BEGIN{printf "Send is %6.2f", ( Send - old_Send ) / 1024 / 1024 / intervel * 8}'` 

 echo "`date +'%Y-%m-%d %H:%M:%S'` Speed: IN ${diff_1} mbps OUT ${diff_2} mbps"

 old_Rev=$Rev
 old_Send=$Send
done