Package Management Week: RPM Basics

The Fedora linux distribution is comprised of thousands of RPM packages. RPM stands for RPM Package Manager and refers to the package format, the tool used to manage packages, and the overall package system. RPM is important not only to Fedora but to the entire Linux community, because it is the package format specified in ISO 23360, the Linux Standard Base.

An RPM package is a single file containing all of the components necessary to install one feature, such as a software application, a group of related utilities, a driver, or a set or fonts or artwork files. The components contained in an RPM package may include:

• software (binaries or scripts)
• configuration files
• documentation, including manpages, info files, on-line help files, and text files
• data such as fonts, artwork, sound files, game levels, and XML stylesheets
• sample data files to aid the user in learning how to use an application
• scripts which are executed before or after the package is installed, and before or after the package is removed
• triggers: scripts which are executed when another package is installed or removed
• metadata, or data about the package, including the package name, summary, and description, software version, package revision, build date, packager name, build host, license, source URL (upstream website), and more
• a list of the capabilities provided by the package
• a list of the package's dependencies -- capabilities required in order to successfully install and use the package

The RPM system tracks installed packages in a local database, which is invaluable to a system administrator -- the database makes it easy to find out what is installed, identify the source of mystery files, determine if files have changed, and check which license applies to a package.

When installing a package, the RPM system can determine when other packages are needed to meet dependencies, but RPM itself cannot determine which packages will solve those dependencies. The yum repository system builds on RPM, permitting dependencies to be solved automatically by searching repositories of packages.

In the next few days we'll examine the Fedora package tools in detail:

• Tuesday - Using the rpm command to query the package database as well as install, update, and remove packages.
• Wednesday - Using yum repository tools, including yum, pirut, pup, yum-updatesd, and yumex.
• Thursday - Enabling and disabling repositories and using yum plugins.
• Friday - Package management tips and tricks.