update ip with mail

updateip.sh

#!/bin/sh

function get_my_ip (){
        myint=$(ip r | grep default | grep -Eo "dev .*" | sed "s/dev //g" | tr -d " ")
        echo $(ip a | grep "${myint}:" -A7 | grep "inet " | head -1 | awk {'print $2'} | cut -d"/" -f1)
}

function sendipmail () {
newip=$1
nc smtp.redhat.com 25 <<EOF
HELO redhat
mail from:[email protected]
rcpt to:[email protected]
data
subject:from DELL: My new ip is: $newip
Hi,
my new ip today $(date) is $newip
Thanks, bye
.
quit
EOF

}


ip=$(get_my_ip)

if [[ ! -e /opt/serv/myip ]]; then
        echo $ip > /opt/serv/myip
        sendipmail $ip
else
        oldip=$(cat /opt/serv/myip)
        if [[ "$ip" != "$oldip" ]]; then
                echo $ip > /opt/serv/myip
                sendipmail $ip
        fi
fi