After you quit dselect, you'll be presented with the login:
prompt. You can now log in using the personal login and password you selected;
your system is now ready to use. Let's examine what it means to log in and how
this process works.
To use Debian, you must identify yourself to the system. This is so it knows
who you are, what you have permission to do, and what your preferences are.
To this end, you have a username or login. If you installed
Debian yourself, you should have been asked to give such a name during installation.
If you are logging on to a system administered by someone else, you'll have
to ask him for an account on the system and a corresponding username.
You also have a password, so no one else can pretend to be you. If you don't
have a password, anyone can log on to your computer from the Internet and do
bad things. If you're worried about security, you should have a password.
Many people prefer to trust others not to do anything malicious with their account;
hopefully your work environment doesn't encourage paranoia. This is a perfectly
reasonable attitude; it depends on your personal priorities and your environment.
Obviously a home system does not need to be as secure as a military installation.
Debian allows you to be as secure or as insecure as you like.
When you start Debian, you'll see a prompt: a request from the computer
for some information. In this case, the prompt is login:.
You should type your username and, when requested, your password. The password
does not appear on the screen as you type it. Press Enter after both
the username and the password. If you type your username or password incorrectly,
you'll have to start over.
If you do it correctly, you'll see a brief message and then a $ prompt.
The $ is printed by a special program called the shell and
is thus called a shell prompt. This is where you give commands to the
system.
Try entering the command whoami now. There is a cursor to
the right of the shell prompt. Your cursor is a small underscore or rectangle
that indicates where you're typing; it should move as you type. Always press
Enter when you're done typing a shell command.
whoami tells your username. You'll then get a new shell prompt.
For the rest of the book, when we say to enter a command, you should type it
at the shell prompt and press the Enter key.
When you're done working, you may want to log out of the system. To exit the
shell, enter the exit command. Keep in mind that if you remain logged
in, someone could come along and use your account. Hopefully you can trust those
in your office or home not to do this; but if you do not trust your environment,
you should be certain to log out when you leave.