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


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


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:


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


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


Components of the X Window System

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

– X client

– Window manager

– Graphical libraries

– Desktop environment


Components of the X Window System


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


X Window Packages Installed with Red Hat Linux 7.3


The fvwm Window Manager


A Sawfish Configuration Window in Gnome


The switchdesk Utility


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)


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


Remotely Displaying an X Client


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


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


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


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


The Xconfigurator Utility


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


A Sample Question Posed by xf86config


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


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


The Start-up Process for the X Window System


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


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


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


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


The KDE Desktop


The KDE File Manager


The KDE Control Center


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


The Gnome Desktop


Configuring Gnome Features


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


The GDM Configurator


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


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

Documents

Guide to Linux Installation and Administration, 2e1 Chapter 5 Using Linux Graphical Environments