deb-version(7) — Linux manual page


deb-version(7)                 dpkg suite                 deb-version(7)

NAME         top

       deb-version - Debian package version number format

SYNOPSIS         top


DESCRIPTION         top

       Version numbers as used for Debian binary and source packages
       consist of three components. These are:

       epoch  This is a single (generally small) unsigned integer.  It
              may be omitted, in which case zero is assumed.  If it is
              omitted then the upstream-version may not contain any

              It is provided to allow mistakes in the version numbers of
              older versions of a package, and also a package's previous
              version numbering schemes, to be left behind.

              This is the main part of the version number.  It is
              usually the version number of the original (“upstream”)
              package from which the .deb file has been made, if this is
              applicable.  Usually this will be in the same format as
              that specified by the upstream author(s); however, it may
              need to be reformatted to fit into the package management
              system's format and comparison scheme.

              The comparison behavior of the package management system
              with respect to the upstream-version is described below.
              The upstream-version portion of the version number is

              The upstream-version may contain only alphanumerics (“A-
              Za-z0-9”) and the characters . + - : ~ (full stop, plus,
              hyphen, colon, tilde) and should start with a digit.  If
              there is no debian-revision then hyphens are not allowed;
              if there is no epoch then colons are not allowed.

              This part of the version number specifies the version of
              the Debian package based on the upstream version.  It may
              contain only alphanumerics and the characters + . ~ (plus,
              full stop, tilde) and is compared in the same way as the
              upstream-version is.

              It is optional; if it isn't present then the upstream-
              version may not contain a hyphen.  This format represents
              the case where a piece of software was written
              specifically to be turned into a Debian package, and so
              there is only one “debianization” of it and therefore no
              revision indication is required.

              It is conventional to restart the debian-revision at ‘1’
              each time the upstream-version is increased.

              Dpkg will break the version number apart at the last
              hyphen in the string (if there is one) to determine the
              upstream-version and debian-revision. The absence of a
              debian-revision compares earlier than the presence of one
              (but note that the debian-revision is the least
              significant part of the version number).

   Sorting algorithm
       The upstream-version and debian-revision parts are compared by
       the package management system using the same algorithm:

       The strings are compared from left to right.

       First the initial part of each string consisting entirely of non-
       digit characters is determined.  These two parts (one of which
       may be empty) are compared lexically.  If a difference is found
       it is returned.  The lexical comparison is a comparison of ASCII
       values modified so that all the letters sort earlier than all the
       non-letters and so that a tilde sorts before anything, even the
       end of a part.  For example, the following parts are in sorted
       order: ‘~~’, ‘~~a’, ‘~’, the empty part, ‘a’.

       Then the initial part of the remainder of each string which
       consists entirely of digit characters is determined.  The
       numerical values of these two parts are compared, and any
       difference found is returned as the result of the comparison.
       For these purposes an empty string (which can only occur at the
       end of one or both version strings being compared) counts as

       These two steps (comparing and removing initial non-digit strings
       and initial digit strings) are repeated until a difference is
       found or both strings are exhausted.

       Note that the purpose of epochs is to allow us to leave behind
       mistakes in version numbering, and to cope with situations where
       the version numbering scheme changes.  It is not intended to cope
       with version numbers containing strings of letters which the
       package management system cannot interpret (such as ‘ALPHA’ or
       ‘pre-’), or with silly orderings.

NOTES         top

       The tilde character and its special sorting properties were
       introduced in dpkg 1.10 and some parts of the dpkg build scripts
       only gained support for it later in the 1.10.x series.

SEE ALSO         top

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

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
       ⟨⟩ on 2021-08-27.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2021-06-17.)  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

1.19.6-2-g6e42d5               2019-03-25                 deb-version(7)

Pages that refer to this page: deb-buildinfo(5)deb-changelog(5)deb-changes(5)deb-control(5)deb-src-control(5)dsc(5)