Here’s a quick script I wrote some years ago to notify me when an interactive session is being launched from one of my servers. Feel free to modify/use however you see fit. Thanks!
#!/bin/bash
# Place this in /etc/profile.d/whatever-name-you-like.sh
NOTIFYADDRRESS="your_email_address"
FROMADDRESS="sending_email_address"
THESYSTEM=`hostname`
THATUSER=`awk -v USER=$UID -F : '$3 == USER {print $1}' /etc/passwd`
CURTIME=`date --rfc-3339=ns`
echo "Login from ${THATUSER} (${UID}) on ${CURTIME}" | mail -aFrom:${FROMADDRESS} -s "${THATUSER} just logged into ${THESYSTEM}" -r ${FROMADDRESS} ${NOTIFYADDRESS}
It just fires off an email whenvever an interactive session is started.