deb-control - Debian packages' master control file format
Each Debian package contains the master `control' file, which contains
a number of fields, or comments when the line starts with '#'. Each
field begins with a tag, such as Package or Version (case insensitive),
followed by a colon, and the body of the field. Fields are delimited
only by field tags. In other words, field text may be multiple lines in
length, but the installation tools will generally join lines when
processing the body of the field (except in the case of the Description
field, see below).
Package: <package name>
The value of this field determines the package name, and is used
to generate file names by most installation tools.
Version: <version string>
Typically, this is the original package's version number in
whatever form the program's author uses. It may also include a
Debian revision number (for non-native packages). The exact
format and sorting algorithm are described in deb-version(5).
Maintainer: <fullname email>
Should be in the format `Joe Bloggs <email@example.com>', and is
typically the person who created the package, as opposed to the
author of the software that was packaged.
Description: <short description>
The format for the package description is a short brief summary
on the first line (after the "Description" field). The following
lines should be used as a longer, more detailed description.
Each line of the long description must be preceded by a space,
and blank lines in the long description must contain a single
'.' following the preceding space.
This is a general field that gives the package a category based
on the software that it installs. Some common sections are
`utils', `net', `mail', `text', `x11' etc.
Sets the importance of this package in relation to the system as
a whole. Common priorities are `required', `standard',
`optional', `extra' etc.
In Debian, the Section and Priority fields have a defined set of
accepted values based on the Policy Manual. A list of these values can
be obtained from the latest version of the debian-policy package.
This field is usually only needed when the answer is `yes'. It
denotes a package that is required for proper operation of the
system. Dpkg or any other installation tool will not allow an
Essential package to be removed (at least not without using one
of the force options).
The architecture specifies which type of hardware this package
was compiled for. Common architectures are `i386', `m68k',
`sparc', `alpha', `powerpc' etc. Note that the all option is
meant for packages that are architecture independent. Some
examples of this are shell and Perl scripts, and documentation.
The name of the distribution this package is originating from.
The url of the bug tracking system for this package. The current
used format is <bts_type>://<bts_address>, like
The upstream project home page URL.
Tag: <tag list>
List of tags describing the qualities of the package. The
description and list of supported tags can be found in the
Source: <source name>
The name of the source package that this binary package came
from, if different than the name of the package itself.
Depends: <package list>
List of packages that are required for this package to provide a
non-trivial amount of functionality. The package maintenance
software will not allow a package to be installed if the
packages listed in its Depends field aren't installed (at least
not without using the force options). In an installation, the
postinst scripts of packages listed in Depends: fields are run
before those of the packages which depend on them. On the
opposite, in a removal, the prerm script of a package is run
before those of the packages listed in its Depends: field.
Pre-Depends: <package list>
List of packages that must be installed and configured before
this one can be installed. This is usually used in the case
where this package requires another package for running its
Recommends: <package list>
Lists packages that would be found together with this one in all
but unusual installations. The package maintenance software will
warn the user if they install a package without those listed in
its Recommends field.
Suggests: <package list>
Lists packages that are related to this one and can perhaps
enhance its usefulness, but without which installing this
package is perfectly reasonable.
The syntax of Depends, Pre-Depends, Recommends and Suggests fields is a
list of groups of alternative packages. Each group is a list of
packages separated by vertical bar (or `pipe') symbols, `|'. The groups
are separated by commas. Commas are to be read as `AND', and pipes as
`OR', with pipes binding more tightly. Each package name is optionally
followed by a version number specification in parentheses.
A version number may start with a `>>', in which case any later version
will match, and may specify or omit the Debian packaging revision
(separated by a hyphen). Accepted version relationships are ">>" for
greater than, "<<" for less than, ">=" for greater than or equal to,
"<=" for less than or equal to, and "=" for equal to.
Breaks: <package list>
Lists packages that this one breaks, for example by exposing
bugs when the named packages rely on this one. The package
maintenance software will not allow broken packages to be
configured; generally the resolution is to upgrade the packages
named in a Breaks field.
Conflicts: <package list>
Lists packages that conflict with this one, for example by
containing files with the same names. The package maintenance
software will not allow conflicting packages to be installed at
the same time. Two conflicting packages should each include a
Conflicts line mentioning the other.
Replaces: <package list>
List of packages files from which this one replaces. This is
used for allowing this package to overwrite the files of another
package and is usually used with the Conflicts field to force
removal of the other package, if this one also has the same
files as the conflicted package.
Provides: <package list>
This is a list of virtual packages that this one provides.
Usually this is used in the case of several packages all
providing the same service. For example, sendmail and exim can
serve as a mail server, so they provide a common package (`mail-
transport-agent') on which other packages can depend. This will
allow sendmail or exim to serve as a valid option to satisfy the
dependency. This prevents the packages that depend on a mail
server from having to know the package names for all of them,
and using `|' to separate the list.
The syntax of Breaks, Conflicts, Replaces and Provides is a list of
package names, separated by commas (and optional whitespace). In the
Breaks and Conflicts fields, the comma should be read as `OR'. An
optional version can also be given with the same syntax as above for
the Breaks, Conflicts and Replaces fields.
Maintainer: Wichert Akkerman <firstname.lastname@example.org>
Pre-Depends: libc6 (>= 2.0.105)
Description: GNU grep, egrep and fgrep.
The GNU family of grep utilities may be the "fastest grep in the west".
GNU grep is based on a fast lazy-state deterministic matcher (about
twice as fast as stock Unix egrep) hybridized with a Boyer-Moore-Gosper
search for a fixed string that eliminates impossible text from being
considered by the full regexp matcher without necessarily having to
look at every character. The result is typically many times faster
than Unix grep or egrep. (Regular expressions containing backreferencing
will run more slowly, however).
deb(5), deb-version(5), debtags(1), dpkg(1), dpkg-deb(1).