sshmonitor.sh

#!/bin/bash

touch old.txt new.txt mail.txt

who > new.txt

while read -r line
do
	check=$(grep -w "$line" -m 1 old.txt)
	if [[ ! $check ]]
	then
		echo "User" "$(echo "$line" | awk '{print $1}')" "dang nhap thanh cong vao thoi gian" "$(echo "$line" | awk '{print $4}')" "$(echo "$line" | awk '{print $3}')" >> mail.txt
	fi
done < new.txt

cat new.txt > old.txt 

sendmail root@localhost < mail.txt