NAME

       deb - Debian binary package format

SYNOPSIS

       filename.deb

DESCRIPTION

       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

       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 (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.  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),  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 after debian-binary and before control.tar.gz 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.

SEE ALSO

       deb-old(5), dpkg-deb(1), deb-control(5).