自动切换线路的 shell 脚本

这是一个基于 bash 的自动判断线路故障的“伪代码”，根据自己实际需要可以再更改

脚本中用了“位”概念做判断
分别用
00 代表无网络
01 代表 GW1
10 代表 GW2
11 代表 GW1 + GW2
对应十进制分别是 0、1、2、3
先分别 ping，然后用用 case 做判断，因此简化了很多，逻辑显得更加明朗

 

 

#! /bin/bash

echo "BOTH" > /tmp/route_flag

GW1="platinum.3322.org"
GW2="platinum.net.cn"

while :;
do
        FLAG="0"

        if ping -c1 -wa $GW1 &>/dev/null; then
                FLAG=`expr 1 + $FLAG`
        fi

        if ping -c1 -wa $GW2 &>/dev/null; then
                FLAG=`expr 2 + $FLAG`
        fi

        case "$FLAG" in
                0)
                        echo "NONE" > /tmp/route_flag
                        ;;
                1)
                        if [ "`cat /tmp/route_flag`" != "GW1" ]; then
                                echo "使用 GW1 做路由"
                                echo "GW1" > /tmp/route_flag
                        fi
                        ;;
                2)
                        if [ "`cat /tmp/route_flag`" != "GW2" ]; then
                                echo "使用 GW2 做路由"
                                echo "GW2" > /tmp/route_flag
                        fi
                        ;;
                3)
                        if [ "`cat /tmp/route_flag`" != "BOTH" ]; then
                                echo "使用双路由"
                                echo "BOTH" > /tmp/route_flag
                        fi
                        ;;
        esac

        sleep 5
done