25

Chapter 6

Basics of the Debian package

management system

6.1 What is a Debian package?

Packages generally contain all of the files necessary to implement a set of related commands

or features. There are two types of Debian packages:

  Binary packages, which contain executables, configuration files, man/info pages, copy 

right information, and other documentation. These packages are distributed in a Debian 

specific archive format (see `What is the format of a Debian binary package?' on the fol 

lowing page); they are usually distinguished by having a '.deb' file extension. Binary

packages can be unpacked using the Debian utility

dpkg

; details are given in its manual

page.

  Source packages, which consist of a

.dsc

file describing the source package (including the

names of the following files), a

.orig.tar.gz

file that contains the original unmod 

ified source in gzip compressed tar format and usually a

.diff.gz

file that contains

the Debian specific changes to the original source. The utility

dpkg source

packs and

unpacks Debian source archives; details are provided in its manual page.

Installation of software by the package system uses  dependencies  which are carefully de 

signed by the package maintainers. These dependencies are documented in the

control

file

associated with each package. For example, the package containing the GNU C compiler (

gcc

)

 depends  on the package

binutils

which includes the linker and assembler. If a user at 

tempts to install

gcc

without having first installed

binutils

, the package management sys 

tem (dpkg) will send an error message that it also needs

binutils

, and stop installing

gcc

.

(However, this facility can be overridden by the insistent user, see

dpkg(8)

.) See more in

`What is meant by saying that a package Depends, Recommends, Suggests, Conflicts, Replaces or

Provides another package?' on page

30

below.

Debian's packaging tools can be used to: