定时 ping 判断网络状态

通过shell脚本编写：

#!/bin/sh
tries=0
ok=0
echo --- my watchdog start ---
while [ "1" = "1" ]
        do
                if /bin/ping -c 1 114.114.114.114 >/dev/null 
                then  echo "net is  fine!"   >/dev/null 
                else
                  echo "net is  offline!"  
                  tries=$((tries+1))
                        if [ $tries -gt 20 ] ;  
                                 then   
                                        tries=0
                                        /app/reconnect.sh  & 
                                        killall  -9 quectel-CM
                                 else
                                 echo $tries
                        fi
                fi
        sleep 3
        done

定时去ping 114，获取网络状态，网络断开达到设定期限，需要重启网络。