deb(5)
NAME
deb - Debian binary package format
SYNOPSIS
filename.deb
DESCRIPTION
The .deb format is the Debian binary package file format. It is understood by dpkg 0.93.76 and later, and is generated by default by all versions of dpkg since 1.2.0 and all i386/ELF versions since 1.1.1elf.
The format described here is used since Debian 0.93; details of the old
format are described in deb-old(5).
FORMAT
The file is an ar archive with a magic value of !<arch>. The file
names might contain a trailing slash.
The tar archives currently allowed are, the old-style (v7) format, the
pre-POSIX ustar format, a subset of the GNU format (only the new style
long pathnames and long linknames, supported since dpkg 1.4.1.17), and
the POSIX ustar format (long names supported since dpkg 1.15.0).
Unrecognized tar typeflags are considered an error.
The first member is named debian-binary and contains a series of lines,
separated by newlines. Currently only one line is present, the format
version number, 2.0 at the time this manual page was written. Programs
which read new-format archives should be prepared for the minor number
to be increased and new lines to be present, and should ignore these if
this is the case.
If the major number has changed, an incompatible change has been made
and the program should stop. If it has not, then the program should be
able to safely continue, unless it encounters an unexpected member in
the archive (except at the end), as described below.
The second required member is named control.tar.gz. It is a gzipped
tar archive containing the package control information, as a series of
plain files, of which the file control is mandatory and contains the
core control information. The control tarball may optionally contain an
entry for `.', the current directory.
The third, last required member is named data.tar. It contains the
filesystem as a tar archive, either not compressed (supported since
dpkg 1.10.24), or compressed with gzip (with .gz extension), xz (with
.xz extension, supported since dpkg 1.15.6), bzip2 (with .bz2 extension, supported since dpkg 1.10.24) or lzma (with .lzma extension, supported since dpkg 1.13.25).
These members must occur in this exact order. Current implementations
should ignore any additional members after data.tar. Further members
may be defined in the future, and (if possible) will be placed after
these three. Any additional members that may need to be inserted before
data.tar and which should be safely ignored by older programs, will
have names starting with an underscore, `_'.
Those new members which won't be able to be safely ignored will be
inserted before data.tar with names starting with something other than
underscores, or will (more likely) cause the major version number to be
increased.