In addition to RPM packages, which we have already discussed, you will encounter other package types, the most common ones being DEB packages for the Debian Linux distribution and TAR.GZ or TAR.BZ2 which are not technically packages but rather archived and compressed sets of files. Out of the box, SUSE 9.1 can handle RPM files with YaST and TAR.GZ/BZ2 files by using the built in ARK unzip utility from the right click menu. DEB packages are not supported, though they can be if you add the right software.

Not every RPM package contains an executable program. Some contain the raw source code of a program, which needs to be compiled before it can be used, some contain developer versions of the code to enable other programmers to build upon it easily, and many contain libraries. Linux Libraries are sets of code which can be easily accessed and used by installed programs, adding a degree of modularity and easing the task of software creation. Almost all Linux software depends on one or more of these libraries in order to function correctly, so it comes as no surprise that library files make up most of the dependencies you will encounter when installing new packages.

Library filenames start with 'lib', for example 'libGL' or 'libexif'. You can see a bunch of them by pointing Konqueror to '/usr/lib'.

When providing packages for download, it is quite common for Linux software authors to also create an RPM package of the source code for their application. These source RPMs are identified by having 'src' somewhere in the package filename (for example 'rssowl-1.1-0.1.src.rpm'), and cannot be installed like a 'normal' package.

Installing packages that depend on other packages

Quite often, programs you would like to install on your Linux machine will require that other programs or packages be installed first. The solution for this, as you might imagine, is to track these programs/packages down and install them.

As an example of this, let's try to install RSSOwl, an RSS feed-reading program. As we are about to find out, this program requires a library which is not installed by default in SUSE 9.1. As we are also about to find out, that library requires another couple of libraries to be installed in turn. Welcome to the package dependency blues! Fortunately, YaST makes figuring out which packages are needed quite a simple process.

To facilitate this demonstration, we are going to take advantage of an invaluable resource for Linux users, www.rpmfind.net. This site is a frequently updated repository for RPMs of all kinds, from libraries to full programs tailored to a variety of distributions. If you are looking to add any program to your Linux installation, or need a package to complete an installation, this should be your first port of call.

To start with, go to www.rpmfind.net and enter 'rssowl' in the search bar. Take a look at the results. As you can see, rpmfind stores several versions. We'd like the most recent, and not the source file (as mentioned above) so click the 'rssowl-1.0.2-0.2.i586.rpm' link to download it to your Home directory.

As we did when installing Xnap, find the RSSowl RPM file and click it, then hit 'install package with YaST'.

Hmm… We are missing the 'libcairo' library package. Make a note of the name of the missing package, then click cancel and close the YaST package installation window.