guide to linux installation and administration, 2e1 chapter 5 using linux graphical environments

Guide to Linux Installation and Administration, 2e 1

Chapter 5

Using Linux Graphical Environments

Guide to Linux Installation and Administration, 2e 2

Objectives

In this chapter, you will:

• Understand how the X Window System functions

• Review the installation and settings of the X Window System

• Use popular graphical desktop interfaces

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Understanding the X Window System

• The installation program automatically detects your graphical hardware and configures the graphical environment

• The foundation of that environment is the software that communicates with the video card and makes all other graphical interaction possible

Valued Gateway Client:

Valued Gateway Client:

Guide to Linux Installation and Administration, 2e 4

A Brief History of X

• The X Window System was developed by MIT and DEC

• The X Window System was released as public domain software in 1985

• The XFree86 Project created a version of X for Intel-based Linux and Unix

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Technical Concepts behind X

• Developers of X designed a text-based configuration file that lets the user write the driver for any video card

• The Xfree86 Project and Linux vendors developed configuration utilities to set up or refine the graphical configuration

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Components of the X Window System

• List of components of X Window System:– X server

– X client

– Window manager

– Graphical libraries

– Desktop environment

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Components of the X Window System

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Exploring X Components

• Each user can select a window manager, desktop interface, and configuration options for that desktop

• A window manager or desktop interface provides the user interface to X

• Older, basic window managers like fvwm and twm are still in use

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X Window Packages Installed with Red Hat Linux 7.3

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The fvwm Window Manager

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A Sawfish Configuration Window in Gnome

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The switchdesk Utility

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Exploring X Components

• Graphical libraries make it easier to create new graphical applications by sharing programming code and system resources

• Two graphical libraries are associated with the Gnome and KDE Desktops:– Qt (on which KDE is based)

– GTK+ (on which Gnome is based)

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Displaying X Clients Remotely

• The DISPLAY variable or display command-line option controls remote display of X applications

• A remote host must permit an application to be displayed by another computer using xhost or xauth functionality

• With the xauth system you can restrict access to those users on a remote system who have a specific token (cookie) in order to use the X server

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Remotely Displaying an X Client

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Running the X Window System

• X Window System is configured during installation

• To configure X after installation, you can use utilities, such as Xconfigurator, xf86config, and others

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Configuring X

• To use XFree86 packages, a window manager, and a desktop interface, configure the X server software to use a video card and a monitor correctly

• You can make changes in the configuration of a window manager or desktop environment

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The Configuration File

• When X Windows System is launched, it relies on the XF86Config-4 configuration file plus a number of scripts that define which X applications should be launched

• The configuration file for XFree86 is located in the /etc directory, in the /etc/X11 directory, or in the /usr/X11R6/lib/X11

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Using Xconfigurator

• The Xconfigurator program creates an XF86Config-4 file for your XFree86 X server using a menu-driven text-based interface

• Xconfigurator probes your hardware and lets you select choices from lists of options

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The Xconfigurator Utility

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Using xf86config

• Xf86config is a command-line configuration utility

• The xf86config utility provides complete flexibility in configuring the XFree86 software

• To launch xf86config, enter the utility name at any Linux command line

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A Sample Question Posed by xf86config

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Configuring X Using Other Resources

• For help configuring X, try the following:– Contact knowledgeable people

– Use specialized software

– Search for information on the Internet

– Buy a commercial X server

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Launching X

• The standard method to launch X is to execute the startx command

• The startx command automatically executes a number of other commands that launch the X server and run the programs that make up the graphical environment

• Each X client is started as a background application

• A background application is an application that does not prevent the program that started it from going on to other tasks

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The Start-up Process for the X Window System

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Fine Tuning X

• Each graphical application uses a number of X resources such as windows, scroll bars, and fonts

• A collection of default X resource settings applies to all X applications

• The resource settings are compiled into a resource database file

• The main resource database file is called app-defaults

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Fine Tuning X

• The xrdb command loads an initial X database resource file or adds resource configuration details from files

• The xset command controls aspects of X such as keyboard repeat rate and screen blanking

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Using Desktop Interfaces

• A desktop interface is a graphical environment that provides a collection of functions and utilities

• Some types of information may be much easier to work with in a graphical format

• Linux desktop interfaces are KDE and Gnome

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The KDE Interface

• In 1996 Matthias Ettrich started the K Desktop Environment (KDE) project

• KDE provides a convenient desktop interface with icons, menus, and taskbars

• KDE includes a powerful file manager and many graphical applications for configuring the KDE interface

• The entire KDE project uses an OpenSource license

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The KDE Desktop

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The KDE File Manager

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The KDE Control Center

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The Gnome Desktop

• Gnome is a desktop interface very similar to KDE

• Gnome uses a GPL license• Gnome provides a set of productivity

applications and system administration utilities similar to those included with KDE

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The Gnome Desktop

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Configuring Gnome Features

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Using a Graphical Login Screen

• The graphical login prompt is provided by the xdm program

• The xdm versions specific to KDE and Gnome are called kdm and gdm, respectively

• xdm restarts automatically to provide a graphical login screen

• xdm selects which programs to start based on the session chosen by the user

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The GDM Configurator

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Summary

• The X Window System is a graphical environment developed by MIT and DEC in 1985

• Components of X include– X server: interacts with the video card

– X client: graphical application what uses the services of the X server

• A window manager or desktop interface provides the user interface to X

• Qt and GTK+ are the most widely used graphical libraries

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Summary

• The DISPLAY variable or display command-line option controls remote display of X applications

• Xconfigurator and xf86config utilities are used to configure X after installation

• Graphical applications include X resources what can be configured

• KDE and Gnome are popular desktop interfaces• The graphical login prompt is provided by the

xdm program, or the kdm or gdm versions for KDE or Gnome