一个监控网卡流量的shell脚本

实现代码：

#!/bin/bash

eth_in_old=$(ifconfig eth0|grep "rx bytes"|sed 's/rx bytes://'|awk '{print $1}')
eth_out_old=$(ifconfig eth0|grep "rx bytes"|sed 's/.*tx bytes://'|awk '{print $1}')

sleep 1

eth_in_new=$(ifconfig eth0|grep "rx bytes"|sed 's/rx bytes://'|awk '{print $1}')
eth_out_new=$(ifconfig eth0|grep "rx bytes"|sed 's/.*tx bytes://'|awk '{print $1}')
eth_in=$(echo "scale=2;($eth_in_new - $eth_in_old)/1000.0"|bc)
eth_out=$(echo "scale=2;($eth_out_new - $eth_out_old)/1000" | bc)
echo "in: $eth_in kb"
echo "out:$eth_out kb"

输出：
[root@localhost hbshell]# ./traffic.sh

in: 1.74 kb
out:1.17 kb