Send email when someone ssh's into the server

email_ssh_login.sh

#!/bin/bash

while true
do
    # Search for the user string in the auth.log file and extract the relevant information
    session_info=$(grep -oP 'pam_unix\(sshd:session\): session opened for user \K[^ ]+' /var/log/auth.log | grep -oP '^[^\s]+')

    # If session_info is not empty, send an email with the session information
    if [ -n "$session_info" ]
    then
        echo "Session information: $session_info" | mail -s "Session opened" recipient@example.com
    fi

    # Wait for one minute before checking again
    sleep 60
done