I load a script in file .bash_profile, and this script will ask for the right password whenever a user opens a terminal window. If the user enters a wrong code, the script will run exit to stop the current terminal.

if [ $code = "980425" ]; then
    echo hello
else
    exit
fi

But I realize that the user can always use Ctrl + C to stop the script and enter the terminal. How can I avoid that?