Red Hat and Debian Package Managers

Contents:

The Red Hat Package Manager
The Debian Package Manager

This chapter describes the two major Linux packaging systems, the Red Hat Package Manager (RPM) and the Debian GNU/Linux Package Manager.

When you want to install applications on your Linux system, most often you'll find a binary or a source package containing the application you want, instead of (or in addition to) a tar.gz file. A package is a file containing the files necessary to install an application. But note that while the package contains the files you need for installation, the application might require the presence of other files or packages that are not included, such as particular libraries (and even specific versions of the libraries), in order to be able to run. Such requirements are known as dependencies.

Package management systems offer many benefits. As a user, you may find you want to query the package database to find out what packages are installed on the system and their versions. As a system administrator, you need tools to install and manage the packages on your system. And, if you are also a developer, you need to know how to build a package for distribution.

Among other things, package managers:

Any user can list or query packages. However, installing, upgrading, or removing packages generally requires superuser privileges. This is because the packages normally are installed in systemwide directories that are writable only by root. Sometimes you can specify an alternate directory, to install, for example, a package into your home directory or into a project directory where you have write permission.

Both RPM and the Debian Package Manager back up old files before installing an updated package. Not only does this let you go back if there is a problem, but also if you've made changes (to configuration files, for example), they aren't completely lost.

Red Hat Package Manager

The Red Hat Package Manager (RPM) is a freely available packaging system for software distribution and installation. In addition to Red Hat and Red Hat-based distributions, both SuSE and Caldera are among the Linux distributions that use RPM.

Using RPM is straightforward. A single command, rpm, has options to perform all the package functions. For example, to find out if the Emacs editor is installed on your system, you could say:

% rpm -q emacs emacs-20.4-4

In addition, the GNOME-RPM program provides an X-based graphical frontend to RPM (that can be run even if you are not running GNOME). This section describes the rpm command and then the gnorpm command that runs GNOME-RPM.

The rpm Command

RPM packages are built, installed, and queried with the rpm command. RPM package names usually end with a rpm extension. rpm has a set of modes, each with its own options. The format of the rpm command is:

rpm [options] [packages]


With a few exceptions, as noted in the lists of options that follow, the first option specifies the rpm mode (e.g., install, query, update, build, etc.), and any remaining options affect that mode.

In the option descriptions that refer to packages, you'll sometimes see them specified as package-name and sometimes as package-file. The package name is the name of the program or application, such as gif2png. The package file is the name of the RPM file: gif2png-2.2.5-1.i386.rpm.

RPM provides a configuration file for specifying frequently used options. The system configuration file is usually /etc/rpmrc, and users can set up their own $HOME/.rpmrc file. You can use the --showrc option to show the values RPM will use for all the options that may be set in an rpmrc file:

rpm --showrc

The rpm command includes FTP and HTTP clients, so you can specify an ftp:// or http:// URL to install or query a package across the Internet. You can use an FTP or HTTP URL wherever package-file is specified in the commands presented here.

Any user can query the RPM database. Most of the other functions require superuser privileges.

General options

The following options can be used with all modes:

Install, upgrade, and freshen options

Install or upgrade an RPM package. The syntax of the install command is:

rpm -i [install-options] package_file ... rpm --install [install-options] package_file ...

To install a new version of a package and remove an existing version at the same time, use the upgrade command instead:

rpm -U [install-options] package_file ... rpm --upgrade [install-options] package_file ...

One feature of -U is that if the package doesn't already exist on the system, it acts like -i and installs it. To prevent that behavior, you can freshen a package instead; in that case, rpm upgrades the package only if an earlier version is already installed. The freshen syntax is:

rpm -F [install-options] package_file ... rpm --freshen [install-options] package_file ...

Installation and upgrade options are:

Query options

The syntax for the query command is:

rpm -q[information-options] [package-options] rpm --query[information-options] [package-options]

There are two subsets of query options: package selection options that determine what packages to query and information selection options that determine what information to provide.

Package selection options

Information selection options

Uninstall options

The syntax for the uninstall command is:

rpm -e package_name rpm --erase package_name

The uninstall options are:

Verify options

The syntax for the verify command is:

rpm -V|-y| -- verify[package-selection-options]

Verify mode compares information about the installed files in a package with information about the files that came in the original package and displays any discrepancies. The information compared includes the size, MD5 sum, permissions, type, owner, and group of each file. Uninstalled files are ignored.

The package selection options include those available for query mode, as well as the following:

The output is formatted as an eight-character string, possibly followed by a "c" to indicate a configuration file, and then the filename. Each of the eight characters in the string represents the result of comparing one file attribute to the value of that attribute from the RPM database. A period () indicates that the file passed that test. The following characters indicate failure of the corresponding test:

MD5 sum
D Device
G Group
L Symlink
M Mode (includes permissions and file type)
S File size
T Mtime
U User

Database rebuild options

The syntax of the command to rebuild the RPM database is:

rpm --rebuilddb [options]

You also can build a new database:

rpm --initdb [options]

The options available with the database rebuild mode are the --dbpath and --root options described earlier under "General options".

Signature check options

RPM packages may have a PGP signature built into them. PGP configuration information is read from /etc/rpmrc. The syntax of the signature-check mode is:

rpm --checksig package_file... rpm -K package_file...

The signature-checking options are:

Two other options let you add signatures to packages:

Miscellaneous options

Several additional rpm options are available:

FTP/HTTP options

The following options are available for use with ftp:// and http:// URLs in install, update, and query modes:

Build options

The syntax for the build options is:

rpm -[b|t]step [build-options] spec-file ...


Specify -b to build a package directly from a spec file or -t to open a tarred gzipped file and use its spec file. Both forms take the following single-character step arguments:

The following additional options can be used when building an rpm file:

Two other options can be used standalone with rpm to recompile or rebuild a package:

RPM examples

Query the RPM database to find Emacs-related packages:

% rpm -q -a | grep emacs

Query an uninstalled package, printing information about the package, and list the files it contains:

% rpm -qpil ~/downloads/bash2-doc-2.03-8.i386.rpm

Install a package (assumes superuser privileges):

% rpm -i sudo-1.5.3-6.i386.rpm


GNOME-RPM

GNOME-RPM is a graphical user frontend to rpm that runs under X. You can run gnorpm even if you are not running GNOME. When you run gnorpm, it opens a window that lets you manage your rpm packages via a graphical interface. The format of the gnorpm command is:

gnorpm [options]


gnorpm options

The gnorpm options are:

The GNOME-RPM window

The GNOME-RPM main window has five parts. At the top is a menu bar with three buttons:

Below the menu bar is a toolbar, with buttons to Install, Unselect, Uninstall, Query, Verify, Find, and Web find. At the very bottom of the window is a status bar.

The rest of the window is the main panel. On the left is the package panel, which displays package folders in a tree structure. Clicking on a folder selects it; double-click to display the contents of the folder (i.e., the packages in that folder) on the righthand panel. Clicking on a package selects it; you then can use the menus and the toolbar buttons to operate on the package. You can select several packages at the same time and operate on them as a group. Right-clicking on a package icon selects the package if it isn't already and presents a menu with Query, Uninstall, and Verify options.

See the GNOME-RPM documentation and online help for full details.