deb(5)                            dpkg suite                            deb(5)

       deb - Debian binary package format


       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).

       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), xz (with .xz extension, supported since 1.17.6) or zstd
       (with .zst extension, supported since, as a series of
       plain files, of which the file control is mandatory and contains the
       core control information, the 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 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), zstd (with .zst extension,
       supported since, bzip2 (with .bz2 extension, supported
       since dpkg 1.10.24) or lzma (with .lzma extension, supported since dpkg

       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



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

1.19.6                            2019-04-02                            deb(5)