Monitor Wan ip for Rasberry pi

#! /bin/sh

SUBJ="Warning: Raspberry Pi - new IP Address"
SUBJ2="Still same wan IP"
EMAIL=xxx@gmail.com"

ip1=""
ip2=""

read ip1 < ip.txt
ip2=$(wget -qO- ifconfig.me/ip)

if [ "$ip1" = "$ip2" ]
then
  echo "Wan ip same yesterday : $ip1."| mail -s "$SUBJ2" $EMAIL;
else
  echo "$ip2" > ip.txt;
  echo "New ip for rpi69: $ip2" | mail -s "$SUBJ" $EMAIL;
  exit;
fi

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ตั้ง cron -e  ทุก 10.10

10 10 * * * /home/chkipwan.sh