This section describes the RPM package management system. You’ll use a package whenever you install an application on JDS. We introduced packages in Chapter 5, along with basic information on how to install them. This appendix, based on material from Linux in a Nutshell (O’Reilly), tells you in detail how to install, upgrade, delete, and check for packages on your JDS system. JDS has some significant differences from other versions of Linux. A package is a compressed file containing the files necessary to install an application or another piece of software, such as a library. Many applications require the presence of other files or packages, such as particular libraries (and even specific versions of the libraries). Such requirements are known as dependencies. No package can be installed until all the packages it depends on are installed. When you attempt to install a package, error messages tell you whether other packages are needed.
Package management systems offer many benefits. As a user, you may want to query the package database to find out what packages are installed on the system and what their versions are. If you are a developer, you need to know how to build a package for distribution.
Among other things, package managers do the following:
Provide tools for installing, updating, removing, and managing the software on your system
Allow you to install new or upgraded software directly across a network
Tell you what software package a particular ...