LinuxQuestions.org - Simple bash script to check current ip and email new ip if changed

Hello all,
I've been creating various scripts to hone my scripting skills so I thought I'd share this here. It's just a simple bash script to check current ip address and, if it has changed, email the new current ip to specified address. You may need to create a couple empty files if they don't yet exist. (e.g. currentip.txt and oldip.txt) I may add in a test to check for existence and create if necessary at a later date.

Note that you will need to change /PATH/TO/SCRIPT to the proper location

Code:

#!/bin/bash



IP=$(curl ipinfo.io/ip)

DIFF=$(diff /PATH/TO/SCRIPT/currentip.txt <(echo "$IP"))

if [ "$IP" ]

then



    if [ "$DIFF" = "" ]

    then

        :

    elif [ "$DIFF" != "" ]

    then

        mv /PATH/TO/SCRIPT/currentip.txt /PATH/TO/SCRIPT/oldip.txt        

        echo "$IP" >/PATH/TO/SCRIPT/currentip.txt

        mail -s "SUBJECT" YOUREMAIL@EXAMPLE.COM < /PATH/TO/SCRIPT/currentip.txt

    fi

else    

    :  

fi

Any questions, edits/suggestions are welcome