Post-install: What You Should Really Do First

Okay, you've finally got Linux installed, it boots up and asks you to

Login: root
Password:
[root]#

You log in as "root" (the administrator) using the password you picked during the installation. (The documentation seldom mentions this login name and password, I don't know why. Many new users never get past this point!) You will not see the password as you type it.

Please note a few important things. First, most of the new Linux distributions allow you to create a regular user during the installation. If you did this, you should log in first as that user, not as root. See User and SuperUser below to understand why. Second, most new Linux distributions are very good at detecting graphics hardware, so there is a good chance that your first login will boot straight into GUI mode ("runlevel 5" in most Linuxes). If that happens, obviously you won't need to run the "startx" command explained below.

So you have logged in. Now what?

The Linux Installation and Getting Started Guide (you should have read this by now; if not it's available on-line thanks to The Linux Documentation Project) will tell you to run several commands at the command line to create a new account, shutdown the computer, etc. Don't listen. We are coming from the world of Windows, and we need to leverage the knowledge we already have to get some work done. That means we need to get off this barren command line and back into a GUI where we feel comfortable. On Linux, this means the X Window System.

Don't type win, it won't work. The first time I installed Linux it took me four hours to figure out how to start X, and I'm about to save you that trouble.

[root]# startx

That's it. That's how we get into our GUI, the X Window System. The first thing you should type at the command prompt is startx. Note that this assumes the X Window System is already configured on your system. This is done during installation on some distributions, but requires extra work on others. If startx doesn't work for you, see Introduction to The X Window System for instructions to get it working.

You should now be looking at some variant of a GUI. What you see exactly depends on which version of which distribution you have installed. For my Mandrake Linux system, I get an interface called KDE (the K Desktop Environment) that looks similar to Windows. I have a task bar, a "start" button that gives me a menu, and several desktop icons. Now this feels a little more like home!

Now that we are feeling more comfortable, we can explore the reasons that all the books tell us the same things to do first. If you already know all this and just need to see how to create a user account for yourself skip to Creating Yourself.

User and SuperUser

Linux puts a lot of power at your fingertips. That's the best reason to switch to Linux; it's also the most dangerous thing about the system. Linux controls how much power you can use on the computer based on your Login ID. It keeps a database of all users, and it keeps track of which user owns which files, and which users have permission to view, edit, and execute each file, folder or program. An ordinary user will not be able to do really dangerous things, like editing the user database, or deleting every file on the system.

But right now you are logged in as root. You are not just an ordinary user, you are SuperUser. (SuperUser is a real Unix term, synonymous with root.) There are no restrictions on your power. You have the ability to crash the system and make it otherwise unusable in more ways than you can imagine. As a novice it is very easy to make your system completely unusable with a single erroneous command. Believe me. I speak from experience. The first weekend after I installed Linux, I had to reinstall it FOUR times before I finally got smart and quit destroying it. And I'm a pretty savvy guy around computers, so don't think you're immune just because you know your way around a PC.

Because it is so dangerous to be logged in as root, you should never use this account unless you have to. The root account is meant to be used by the System Administrator to perform certain duties which can be destructive and therefore should only be performed by an expert. Some examples are emptying log files, mounting and unmounting file systems (more on this later under Getting to CD's and Floppies ), installing or removing programs, and creating or deleting user accounts.

If you are using Mandrake Linux, you will have a tool available to perform the most common administration tasks, even when logged in as a regular user. This is called the Mandrake Control Center, which you may find on your desktop or in the Configuration menu. It will ask you for the root password when you start it for security reasons. As a result of this handy tool, you may never need to actually log in as root.

Becoming SuperUser

No phone booth needed. The obvious way is to login as root. That's the best way to do it if you plan on doing a bunch of system maintenance type stuff, but it can be a pain if you're logged in as User with an X session and 14 programs open and connected to the Internet and you just need to copy one file into /usr/lib so you can run this program you just downloaded. Fear not, there is a better way. Type this:

[user]$ su
Password:*****
[root]#

Bang! Just like that, you are SuperUser! A few cautions: Although you are now SuperUser, this is not a "login" shell, so your environment hasn't changed. The biggest way this will effect you is that some programs you normally run as root may appear to be missing. That's because your PATH environment variable, the list of places Linux looks for executables, does not contain /sbin or /usr/sbin. If you try to run a command like shutdown (see below) and it complains, try typing /sbin/shutdown instead. That should do it.

When you are finished with your maintenance tasks you should immediately change back to normal user mode:

[root]# exit
[user]$

Notice that while you are SuperUser, your command prompt looks different. An ordinary user is prompted with the dollar sign ($) while SuperUser gets a pound sign (#). This makes it easy to tell which mode you are in. (This is true on most distributions, but the prompts may be different on different distributions, and they can be customized.)

Creating Yourself

DO NOT SKIP THIS STEP!!! It is very important that you create a user account for yourself and use it while you are learning. If you don't believe me, read User and SuperUser above. If you created a username for yourself when installing Linux, login as that user now and call this step finished. Otherwise, read on.

Bear in mind here that setting up a new user account is the job of the system administrator. Ordinarily you would never see this done, but this is your own PC and that makes you the administrator. It is very important to differentiate between the things an Administrator (or SuperUser) does, and the things a normal user does. The only time you should ever use the root account is when you are performing administrative duties. If you are running programs, playing games, or just exploring, you should be a regular User.

Each distribution has its own tools for creating user accounts. Older versions of Red Hat have the User and Group Configurator while newer versions use a program called linuxconf for all kinds of administrative tasks. Mandrake has a user tool in the Mandrake Control Center, S.u.S.E uses a program called Yast, and so on. You are welcome to explore these tools on your own. However, there is a least common denominator that works on every system.

From a terminal (or xterm window) type:

[root]# useradd vince

Of course, you won't want to be called vince, so fill in your own chosen moniker here. Remember that Linux is case sensitive. If you fill in vince here and then type Vince later, Linux will not recognize you.

This command creates a home directory for you and makes appropriate entries in system files so the system will recognize you. By default it sets your password to a random and un-duplicatable string, which means this account cannot be used until a new password is set. Use the passwd command to set a usable password for this account:

[root]# passwd vince
New UNIX password:
Retype new UNIX password:
passwd: all authentication tokens updated successfully

SuperUser can change any password on the system. A regular user can change his own password using this same command, but cannot change passwords to other accounts.

Getting Out/Shutting Down

Now you should log on as yourself, the user. To exit X and get back to the command prompt, select "Logout" from the main menu (or similar menu options in your version). If your system booted into GUI mode automatically, it may now give you the option to shutdown or restart the computer, or just log out to log in as a different user. Otherwise, you'll need to run the commands below.

If you are running some other window manager that does not provide a menu option like this, and you can find no other way to close down X, hit Ctrl-Alt-Backspace on your keyboard. This will shut down the X server. This is for emergencies only and is not a healthy way to close your X server, so consult the documentation for your distribution to find the correct way.

Now you are back at the command prompt. To log out and return to the Login: prompt, just type:

[root]# logout

If you're ready to turn off the computer, you need to instruct Linux to shut it down properly so that your files are not damaged. To turn off the power type:

[root]# shutdown -h now

To reboot the computer type:

[root]# shutdown -r now

Note, however, that the shutdown command can only be run by the root user. If you try to run it as a regular user, even using the su command, you'll get the message:
shutdown: must be root.

On Linux systems, an alternative is to use the commands /sbin/halt to power down the computer and /sbin/reboot to reboot. These commands can be run by regular users with the proper permissions. This is not universally correct on UNIX systems, so it is recommended not to try this on non-Linux systems.