50.檢測網卡狀態腳本

思路：sar -n DEV 1 10監測網卡進出流量，若是進出流量都爲0則網卡異常
#!/bin/bash
LANG=en#定義語言
if [ $# -ne 1 ] || ! ip addr show $1 &>/dev/null;then 
#輸入參數是否爲1， ! ip addr show判斷網卡是否存在
        echo "Please input correct network card." 
        exit
fi
echo "Checking..."#輸出檢測信息
sar_in=`sar -n DEV 1 10 |grep " $1 "|grep -i average:|awk '{print $5}'`
#進網卡流量
sar_out=`sar -n DEV 1 10 |grep " $1 "|grep -i average:|awk '{print $6}'`
#出網卡流量
if [ "$sar_in" == "0.00" ] && [ "$sar_out" == "0.00" ];then
#判斷進出網卡流量是否都爲0
        while true#while 循環執行判斷是否重啓網卡
        do
             read -p "The network card is down,do you want to restart it?(y or n) " net
             case $net in
             y)
             echo "Restarting..."#輸出重啓信息
             ifdown $1 2>/dev/null
             ifup $1 2>/dev/null
             if [ $? -eq 0 ];then#判斷重啓是否成功
                echo "The network card was restarted successfully!"
                break#退出循環
             else
                echo "DEV $1 failed to start!"
                break#退出循環
             fi
             ;;
             n)
             echo "Bye!"
             exit 1
             ;;
             *)
             echo "Please input y or n."
             continue#從新循環
             ;;
             esac
        done
else
        echo "The network card is in good condition!"
fi
使用 ：sh dev_sar.sh eth0