Although screen savers are no longer the necessity that they once were, many PC users still employ them as a desktop tool. In this column we look at installing the Linux screen saver application and investigate an imaginative screen saver named WebCollage.
The screen saver application for Linux is called XScreenSaver (www.jwz.org/xscreensaver) and includes a large number of screen savers ranging from basic 2D effects to highly advanced 3D OpenGL-based scenery. To compile XScreenSaver, copy the source code to your hard drive and type the following commands in a shell:
$ tar -zxvf $ ./configure $ make
I encountered some problems compiling XScreenSaver with Red Hat Linux 8.0 as a result of the very new version of GCC included with the distribution. If you encounter an error, rerun the ‘make’ command — your problems may be solved.
To install XScreenSaver, log in as root or change to the superuser using the ‘su’ command and type the following:
$ make install
The XScreenSaver binaries will be installed under /usr/local/bin and the screen savers will be installed under /usr/local/lib/xscreensaver. Users of KDE may need to perform an additional installation step to use XScreenSaver properly, because KDE includes a simple configuration interface to XScreenSaver that must be turned off. To disable the screen saver, start the KDE Control Center, select Look & Feel-Screen saver and uncheck the ‘Enable Screen saver’ box. To install XScreenSaver, create a file named ‘xscreensaver.desktop’ in the directory ~/.kde/Autostart/ and add the following to it:
[Desktop Entry] Exec=/usr/local/bin/xscreensaver Name=XScreenSaver Type=Application X-KDE-StartupNotify=false
You will need to restart KDE for the changes to take place.
A GUI tool named ‘xscreensaver-demo’ is available to configure your screen savers. After starting the program you will see a list of available screen savers on the left; select one, and you’ll see a preview of it on the right. You can try any screen saver in full screen mode by selecting it from the list and clicking the Preview button. To configure one, select it and click the Settings button.
One screen saver of particular note (included with XScreenSaver) is WebCollage (www.jwz.org/webcollage). This nifty screen saver performs random searches of the Web using your idle Internet connection and displays a collage of the images it encounters. WebCollage randomly searches the Web, so from time to time it uncovers adult images (See here for a screenshot).
WebCollage requires some external software and configuration before it can be used. The chbg package has been included on this month’s cover CD and must be installed. To compile chbg, first copy the source code to your hard disk and type the following in a shell:
$ ./configure $ make
To install chbg, log in as root and type the following in a shell:
$ make install
To configure the WebCollage screen saver, start xscreensaver-demo, highlight WebCollage from the list of available screen savers and click the Settings button. Add the following line to the box labelled “Per-Image Filter Program”:
/usr/local/lib/xscreen saver/vidwhacker -stdin -stdout
WebCollage can also obtain its images in a much sneakier manner. Using the Driftnet program (on this month’s cover CD), WebCollage can sniff images from an Ethernet network. In other words, WebCollage can display images that your family/friends/colleagues are currently viewing on their computers, if you and they are on the same network. Obviously, Driftnet opens up a range of privacy issues and you shouldn’t use this feature of WebCollage if others will be offended by your snooping.
Driftnet can be compiled and installed by typing in a shell as root:
$ make $ make install
To enable Driftnet support in WebCollage, return to the WebCollage Settings menu and click on the Advanced >> button in the bottom right corner of the window. Add “-driftnet” to the end of the Command Line box and you will be ready to go.