如何使用shell脚本编写ping包及arp的监控并发送短信功能？

#!/bin/bash
NOW="`date +%Y%m%d-%H:%M:%S`"
PHONES=15134567893
IP=10.100.8.78
GATEWAY=10.100.30.1
#ping失误的短信内容
content1="host is failed"
#arp主机网关失误的短信内容
content2="GW is failed"
#ping日志路径
LogFile="/tmp/ping`date "+%Y%m%d-%H-%M-%S"`.log"
#ping对方主机100个包并将结果输出到日志
ping -c100 $IP &> $LogFile
#用if，else语句判断是否ping通，
if [ "$?" == "0" ]; 
 then
  echo "$NOW $IP is ok">> $LogFile
else
  echo "$NOW $IP is down">> $LogFile &/usr/bin/curl -d "phones=$PHONES&content= $NOW $IP $content" "content-type: application/x-www-form-urlencoded;charset=UTF-8" "http://短信网关:8080"
fi
#分隔符
echo "================================" >> $LogFile
#arp自己网关
arp $GATEWAY &>>$LogFile
num=$(cat $LogFile |grep eth0|wc -l)
 if [ "$num" == "0" ]; 
  then
   echo "$NOW $GATEWAY is down">> $LogFile &/usr/bin/curl -d "phones=$PHONES&content= $NOW $GATEWAY $content1" "content-type: application/x-www-form-urlencoded;charset=UTF-8" "http://短信网关:8080"
fi