2 - Raspberry PI Community Projects

• control.tar.gz. This archive file contains all of the available meta-information. In it,
package management tools find, among other things, the name and version of the package.
Some of this meta-information allows them to determine if it is possible to install or
uninstall the programs inside, for example according to the list of packages already on
the machine.
• data.tar.gz. This archive contains all of the files to be extracted from the package; this
is where the executable files, documentation, etc., are all stored. Some packages may use
other compression formats, in which case the file will be named differently (data.tar.
bz2 for bzip2, data.tar.xz for XZ, data.tar.lzma for LZMA).
5.2. Package Meta-Information
The Debian package is not only an archive of files intended for installation. It is part of a larger
whole, and it describes its relationship with other Debian packages (dependencies, conflicts,
suggestions). It also provides scripts that enable the execution of commands at different stages
in the package's lifecycle (installation, removal, upgrades). These data used by the package
management tools are not part of the packaged software, but are, within the package, what is
called its “meta-information” (information about other information).
5.2.1. Description: the control File
This file uses a structure similar to email headers (as defined by RFC 2822). For example, for apt,
the control file looks like the following:
$ apt-cache show apt
Package: apt
Priority: important
Section: admin
Installed-Size: 5612
Maintainer: APT Development Team
Architecture: i386
Version: 0.8.0
Replaces: manpages-pl (= 2.3.4), libgcc1 (>= 1:4.1.1), libstdc++6 (>= 4.4.0),
➥ zlib1g (>= 1:1.1.4), debian-archive-keyring, gnupg
Suggests: aptitude | synaptic | wajig, dpkg-dev, apt-doc, bzip2, lzma, python
➥ -apt
Conflicts: python-apt (