[ Pobierz całość w formacie PDF ]
.) Here is an example of the syntax of the xv command for displaying animage as your desktop background:$ xv -quit -root -max /usr/share/pixmaps/backgrounds/space/apollo17_earth.jpgAs noted earlier, any of these attributes that you want set each time you start your desktop can be added toyour.xinitrc or.xsession files.Tip You can find some nice background images in the Propaganda directories(/usr/share/pixmaps/backgrounds/Propaganda/*).There are also many places to find nice backgroundimages on the Web, including Digital Blasphemy (http://www.digitalblasphemy.com/) and BackgroundPics for Linux (http://heimat.de/ruebe/linux/bgs.html). Screen saverThere is an option that you can add when you run the X server to have a screen saver come on after a setnumber of minutes of idle time.Using the xset command, you can change that timeout value.(As with thebackground examples just shown, your desktop environment may take over control of the screensaverfunction.)There are different ways to initially set the screen saver timeout value when you start X.$ X -s 15$ xinit -- -s 15 serverargs="-s 15"In the first example, you simply run the X command with the -s 15 option to have the screen saver come onafter 15 minutes of inactivity.If you run xinit, two dashes on the command line indicate that the nextarguments are to be passed to the X server (in this case, -s 15 is passed).The last example isn t a command atall.It is a line in the startx command.As the root user, edit the startx command and add -s 15 to theserverargs line between the quotes.This causes the -s 15 argument to be passed to the server.To change the screen saver timeout value after X has started, use the xset command as follows:$ xset s 15You can also add the xset command line to an initialization file (such as.xinitrc), to have it set the timeoutvalue each time the desktop starts up.If you simply want the screen saver off, type xset s off.To turn it on,type xset s on.To have the screen be blanked when it times out, type xset s blank.Tip You now know how to set your screen saver for the desktop.But what if you want to turn off the screensaver when you are in text mode? Just type setterm -blank 0.The screen saver will never come on.X Application resourcesMost X applications support some, or all, of the standard X options (geometry, foreground, background, etc.),as well as some options that are specific to the application.Many of them start with a set of default optionsdefined.You can override these default options in several different ways.There are separate resource files for each X application (that chooses to create one) in the/usr/lib/X11/app-defaults directory.Each file is named after the X client it represents, with the exception thatthe first one or two characters are capitalized.Although it is not recommended, you could edit these files andchange the resources.In that way everyone who starts X on your system will start with the same set ofresources set for their applications.The preferred way to change resources for your X clients is to copy the resource file you want to change toyour home directory.Then make changes and additions to it.When you start the X client that is associatedwith that file, the resources are incorporated into the client.Even if there is no default resource file for an Xclient, you can create one.For example, I created a $HOME/XEyes file and added the following lines to it:XEyes*title: My EyesXEyes*foreground: RedXEyes*background: YellowWhen I ran the xeyes command, the title "My Eyes" appeared on the task bar for the application.The eyeballswere colored yellow and the pupils were red.Instead of using individual files, you can add X resources associated with any client into your.Xresources or.Xdefaults file.When you make a change to those files, you can immediately merge those changes into thecurrent desktop as follows: $ xrdb -merge $HOME/.XresourcesSummaryThe X Window System provides the basis for most graphical user interfaces available for Red Hat and otherLinux systems today.Although X provides the framework for running and sharing applications, the GNOMEand KDE desktop environments, along with a window manager, provide the look-and-feel of your desktop.Using various configuration files and commands, you can change nearly every aspect of your graphicalenvironment.Backgrounds can be assigned a single color or can be filled with single or tiled graphic images.Menus can be changed or enhanced.Multiple virtual workspaces can be used and managed.There are also many settings associated with X itself that you can use directly to change the behavior of yourdesktop. Chapter 5: Accessing and Running ApplicationsOverviewTo get your work done on a computer, you use application programs.They let you create documents, crunchdata, and communicate with others.As an engine for running applications, Red Hat Linux is becoming moreviable every day.Not too long ago, there were only a handful of user-friendly applications available.Nowthere are hundreds and they re getting more powerful and friendlier all the time.This chapter describes how to get applications for Red Hat Linux and run them
[ Pobierz całość w formacie PDF ]
