Absolute Beginners Guide to Networking (4th Edition)

Depending on the distribution of Linux that you are using, there will be various ways to upgrade your system software. You can buy or download a newer version of the software and then upgrade your system by installing from CDs (downloaded Linux distributions come in the form of CD ISOs, which must then be burned to a CD). Upgrading portions of your installation such as the KDE desktop or specific tools can be accomplished by going to the appropriate Web site and downloading the software.

Individual Linux software packages (such as utilities for managing the system and various network resources) can be found in different file formats. For Red Hat you can easily install new software using RPM (Red Hat Package Manager) files. These files have .rpm as their extension. These files have been specially prepared so that they can be installed quickly on your system using the Red Hat Package Manager utility. All you have to do is download the file (typically from www.redhat.com) and then locate it on your system using the Conqueror browser (a combination file and Web browser used on Linux systems where KDE has been installed; we discuss Conqueror later in the chapter). Selecting the file in Conqueror starts the Red Hat Package Manager and allows you to install the software.

You may also run into software packages that exist as compressed tarballs. A tarball is a file archive created with the Unix tar utility. It holds the source files for the software you wish to install. Tarballs will typically be compressed with the Linux utility Gzip to make them easier to download. A typical Gzip compressed tarball will have the extension .tar.gz. In most cases installing tarballs requires some annoying input at the command line in a terminal window. For example, let's say that we have a file named joe.tar.gz. To unzip the package you would open a console on your desktop (in KDE, select the KDE menu then select System Tools, and then Terminal).

In the terminal you would first switch to the directory that holds the file using the cd command (such as cd /directory name ) and then type the following:

tar zxf joe.tar.gz /tmp

The zxf switches are used to unzip the archive ( z ), extract the file ( x ), and specify that this is the archive to work with ( f ). The /tmp at the end of the command will place the unzipped and extracted files into the tmp directory on your system (you can specify a directory other than tmp if you wish).

You can then go to the tmp directory ( cd /tmp ) or other directory that holds the extracted files. Now you have to type the following:

./configure make make install

This creates the installation file for the software and installs it. You should now be able to launch the application (typically from the terminal window or in some cases an icon will be created on the GUI menu system).

The absolute easiest way to upgrade Red Hat Linux (in cases where you purchased the software) is to use the Red Hat Network Alert Notification tool, which allows you to upgrade your Red Hat installation over the Web (other Linux distributions also have systems for upgrading over the Web). On the right side of the GUI toolbar (called the KDE Panel on a KDE desktop), the Red Hat Network Alert icon will let you know when your system is not up to date. The icon will appear as a red circle with an exclamation point in it (as shown in Figure 10.4).

When you click the icon a list of available updates will appear (also shown in Figure 10.4). Click the Launch up2date button in the Red Hat Network Alert Notification tool and you will be walked through the process of upgrading your Red Hat installation (you get to select what you want to upgrade and what you don't want to upgrade). The great thing about upgrading through the Red Hat Web site is that software dependencies are figured out for you, and if additional software is required to make your upgrade work, it will be identified and installed as well.

Caution