Debian GNU/Linux provides several package management tools, primarily intended to facilitate the building, installation, and management of binary packages. Debian package names generally end in .deb. The Debian package management tools include:
Until recently, the most important of the Debian packaging tools and still the primary package management program. Used to install or uninstall packages or as a frontend to dpkg-deb.
Lower-level packaging tool. Used to create and manage the Debian package archives. Accepts and executes commands from dpkg or can be called directly.
The currently available piece of the Advanced Package Tool (APT), which is still being developed and is intended to be a modern, user-friendly package management tool. Can be run from the command line or selected as a method from dselect. One of the features of apt-get is that you can use it to get and install packages across the Internet by specifying an ftp:// or http:// URL. Another feature is that you can use it to upgrade all packages currently installed on your system in a single operation.
Some important files used by the Debian package management tools are:
Comes with each package; documents dependencies; contains the name and version of the package, a description, maintainer, installed size, and so on.
Comes with each package and contains a list of the configuration files associated with the package.
Scripts that can be included in a package to be run before installation, after installation, before removal, or after removal of the package.
Contains information about packages available on the system.
Contains information about the status of packages available on the system.
A list for APT of package sources, used to locate packages. The sources are listed one per line, in order of preference.
The main APT configuration file.
The possible states that a package can be in are:
Only the configuration files for the package are present on the system.
The package is unpacked and configuration was started but not completed.
Installation was started but not completed.
The package is unpacked and configured.
The package is not installed.
The package is unpacked but not configured.
The possible package selection states are:
The package has been selected for deinstallation (i.e., for removal of everything but configuration files).
The package has been selected for installation.
The package has been selected to be purged (i.e., for removal of everything including the configuration files).
There are two possible package flags that can be set for a package. They are:
The package is not to be handled by dpkg, unless forced with the --force-hold option.
The package is broken and needs to be reinstalled. Such a package cannot be removed, unless forced with the --force-reinstreq option.
In addition to the commands described in the next subsection, several shell and Perl scripts are included with the package manager for use in building packages:
Help automate package building. Shell script.
Add an entry for a file to debian/files. Perl script.
Generate an upload control file from the information in an unpacked, built, source tree and the files it has generated. Perl script.
Read information from an unpacked source tree and display a binary package control file on standard output. Perl script.
Rename Debian packages to their full package names. Shell script.
Read and parse the changelog from an unpacked source tree and write the information to standard output in machine-readable form. Perl script.
Create a Packages file from a tree of binary packages. The Packages file is used by dselect to provide a list of packages available for installation. Perl script.
Calculate shared library dependencies for named executables. Perl script.
Pack and unpack Debian source archives. Perl script.
Copyright © 2001 O'Reilly & Associates. All rights reserved.