deb(5) — Linux manual page


deb(5)                         dpkg suite                         deb(5)

NAME         top

       deb - Debian binary package format

SYNOPSIS         top


DESCRIPTION         top

       The .deb format is the Debian binary package file format. It is
       understood since dpkg 0.93.76, and is generated by default since
       dpkg 1.2.0 and 1.1.1elf (i386/ELF builds).

       The format described here is used since Debian 0.93; details of
       the old format are described in deb-old(5).

FORMAT         top

       The file is an ar archive with a magic value of !<arch>.  Only
       the common ar archive format is supported, with no long file name
       extensions, but with file names containing an optional trailing
       slash, which limits their length to 15 characters (from the 16
       allowed).  File sizes are limited to 10 ASCII decimal digits,
       allowing for up to approximately 9536.74 MiB member files.

       The tar archives currently allowed are, the old-style (v7)
       format, the pre-POSIX ustar format, a subset of the GNU format
       (new style long pathnames and long linknames, supported since
       dpkg; large file metadata since dpkg 1.18.24), and the
       POSIX ustar format (long names supported since dpkg 1.15.0).
       Unrecognized tar typeflags are considered an error.  Each tar
       entry size inside a tar archive is limited to 11 ASCII octal
       digits, allowing for up to 8 GiB tar entries.  The GNU large file
       metadata support permits 95-bit tar entry sizes and negative
       timestamps, and 63-bit UID, GID and device numbers.

       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.  It is a tar
       archive containing the package control information, either not
       compressed (supported since dpkg 1.17.6), or compressed with gzip
       (with .gz extension) or xz (with .xz extension, supported since
       1.17.6), zstd (with .zst extension, supported since dpkg
       1.21.18), as a series of plain files, of which the file control
       is mandatory and contains the core control information, the
       md5sums, conffiles, triggers, shlibs and symbols files contain
       optional control information, and the preinst, postinst, prerm
       and postrm files are optional maintainer scripts.  The control
       tarball may optionally contain an entry for ‘.’, the current

       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),
       zstd (with .zst extension, supported since dpkg 1.21.18), 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 after debian-binary and
       before control.tar or 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.

MEDIA TYPE         top




SEE ALSO         top

       deb-old(5), dpkg-deb(1), deb-control(5), deb-conffiles(5),
       deb-md5sums(5), deb-triggers(5), deb-shlibs(5), deb-symbols(5),
       deb-preinst(5), deb-postinst(5), deb-prerm(5), deb-postrm(5).

COLOPHON         top

       This page is part of the dpkg (Debian Package Manager) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report
       for this manual page, see
       ⟨⟩.  This
       page was obtained from the project's upstream Git repository ⟨git
       clone⟩ on 2023-12-22.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2023-12-18.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

1.22.0-52-g1af0                2023-08-30                         deb(5)

Pages that refer to this page: dpkg(1)dpkg-deb(1)dpkg-name(1)dpkg-split(1)dselect(1)deb-control(5)deb-old(5)deb-split(5)deb-version(7)