Chris Tyler - Fedora Linux

Very few of the other X.org video drivers support multiple video outputs. If you have another driver and want to see the options supported, look for a manpage for your driver. For example, to see the driver options for the Intel 810 adapter:

$ man i810

 The manpages for the radeon driver

 NVIDIA closed-source driver information from /usr/share/doc/NVIDIA_GLX-1.0/README.txt

In order to maintain your system effectively, it's necessary to learn some basic system management skills. This chapter covers these essential skills.

With a small investment in time, you'll be able to adjust your system configuration, keep the filesystem under control, disable unused services, and identify and stop rogue processes. I'll cover the basics of performing these operations using both graphical and command-line tools, both locally and remotely.

Many system management tasks can be performed using either of the graphical user interfaces provided with Fedora (i.e., GNOME or KDE). However, most power users prefer the command line for system management work because they find it faster, more consistent between different versions of Linux, and easier to access remotely. The command line is also called a shell prompt , because the commands are processed by a program called a shell; the standard shell on a Fedora system is the Bourne-again shell ( bash ).

If you are logged in to the system through the graphical user interface, access the command line through the terminal program. Select the menu option Applications→Accessories→Terminal (System→Terminal in KDE), or right-click on the desktop background and select Konsole under KDE.

If you find yourself using the terminal frequently, you can make it easier to launch: right-click on the Terminal option in the application menu and select "Add this launcher to panel." A new panel icon will appear that will launch a new terminal when clicked.

If you have logged in to the system through a character-mode login screen or an SSH login, you will automatically be presented with a command line.

The standard shell prompt looks like this:

[chris@concord2 ~]$

This message is an invitation to enter a command. It shows the name of the user ( chris ), the computer being used ( concord2 ), and the current working directory within the filesystem ( ~ , meaning the user's home directory). The last character of the prompt, $ , indicates that this is a normal user's prompt, as opposed to the system administrator's prompt, which ends with # .

To enter a command, simply type it, and then press Enter to execute it. The output from the command will appear after the command (scrolling the screen if necessary), and when the command is done a new prompt will be printed.

To edit a command line, use the left and right arrow keys to position within the line, and the Backspace and Delete keys to delete characters to the left or right of the cursor, respectively. To insert text, simply type it. You can press Enter with the cursor located anywhere on the line to execute the command. Other editing keys are available; Table 4-1 shows the most useful ones.

Table 4-1. Useful editing keys

You can scroll through the history of previously entered commands using the up and down arrow keys. This enables you to easily re-enter a command, either exactly as you previously entered it or after editing.

You can also search for a previous command by pressing Ctrl-R (for reverse search ) and then typing a few characters that appear in the command. For example, if you had at some previous point typed cat /etc/hosts and you pressed Ctrl-R and typed hos , the cat /etc/hosts command would appear (providing that no intervening commands contained the letter sequence hos ).

The superuser account, root , is also called the privileged account, because it is not subject to the security restrictions that are applied to regular user accounts. root access is required for many system administration commands. Although it's tempting to use the root account all the time on a single-user computer, it is unwise because Fedora assumes that you know what you're doing and won't ask for confirmation if you enter a dangerous command; it will just go ahead and execute it. If you're using the root account, an incorrect command can cause a lot more damage than the same command executed in a normal account.

Although you can directly log in as a root user, it's usually much safer to take on root privilege only when necessary, using the su (switch user) command:

$ su

Password:

root-password

#

The shell prompt will change to end in a pound sign ( # ) instead of a dollar sign ( $ ) when you are in root mode. Press Ctrl-D or type exitto drop superuser access and return to your regular shell prompt.

In this book, I'll use $ to indicate any normal user's prompt, user $ to specifically indicate user 's prompt, and # to indicate the root prompt. Avoid entering commands as root unnecessarily!

Many Linux commands will output a message only if something goes wrong. For example, if you try to remove a file using the rm command, no message will be displayed if the file is successfully deleted, but an error message will be generated if the file does not exist:

$ rm barbeque

rm: cannot remove \Q barbeque ': No such file or directory

Most error messages start with the name of the command that produced the message.

You can leave a shell by pressing Ctrl-D or typing exit . If you are using a terminal window and don't have any programs running, you can simply close the window using the X button on the title bar.

The shell prompt is managed by bash , the Bourne-again shell. bash got its name from the fact that it is a successor to the original Unix shell, sh , which is also known as the Bourne shell (after its author, Steve Bourne). bash is a command editor, command interpreter, job controller, and programming language.