deb-substvars(5) — Linux manual page


deb-substvars(5)                 dpkg suite                 deb-substvars(5)

NAME         top

       deb-substvars - Debian source substitution variables

SYNOPSIS         top


DESCRIPTION         top

       Before dpkg-source, dpkg-gencontrol and dpkg-genchanges write their
       control information (to the source control file .dsc for dpkg-source
       and to standard output for dpkg-gencontrol and dpkg-genchanges) they
       perform some variable substitutions on the output file.

       A variable substitution has the form ${variable-name}.  Variable
       names consist of alphanumerics (a-zA-Z0-9), hyphens (-) and colons
       (:) and start with an alphanumeric, and are case-sensitive, even
       though they might refer to other entities which are case-preserving.
       Variable substitutions are performed repeatedly until none are left;
       the full text of the field after the substitution is rescanned to
       look for more substitutions.

       After all the substitutions have been done each occurrence of the
       string ${} (which is not a legal substitution) is replaced with a $

       While variable substitution is done on all control fields, some of
       those fields are used and needed during the build when the
       substitution did not yet occur. That's why you can't use variables in
       the Package, Source and Architecture fields.

       Variable substitution happens on the content of the fields after they
       have been parsed, thus if you want a variable to expand over multiple
       lines you do not have to include a space after the newline. This is
       done implicitly when the field is output. For example, if the
       variable ${Description} is set to "foo is bar.${Newline}foo is
       great." and if you have the following field:

        Description: foo application
         More text.

       It will result in:

        Description: foo application
         foo is bar.
         foo is great.
         More text.

       Variables can be set using the -V common option. They can be also
       specified in the file debian/substvars (or whatever other file is
       specified using the -T option). This file consists of lines of the
       form name=value.  Trailing whitespace on each line, blank lines, and
       lines starting with a # symbol (comments) are ignored.

       Additionally, the following standard variables are available:

       Arch   The current host architecture (i.e. the architecture the
              package is being built for, the equivalent of DEB_HOST_ARCH).

              The source package version (since dpkg 1.13.19).

              The upstream source package version, including the Debian
              version epoch if any (since dpkg 1.13.19).

              The binary package version (which may differ from
              source:Version in a binNMU for example; since dpkg 1.13.19).

              The source package version (from the changelog file). This
              variable is now obsolete and emits an error when used as its
              meaning is different from its function, please use the
              source:Version or binary:Version as appropriate.

              The source package synopsis, extracted from the source stanza
              Description field, if it exists (since dpkg 1.19.0).

              The source package extended description, extracted from the
              source stanza Description field, if it exists (since dpkg

              The approximate total size of the package's installed files.
              This value is copied into the corresponding control file
              field; setting it will modify the value of that field. If this
              variable is not set dpkg-gencontrol will compute the default
              value by accumulating the size of each regular file and
              symlink rounded to 1 KiB used units, and a baseline of 1 KiB
              for any other filesystem object type.

              Note: Take into account that this can only ever be an
              approximation, as the actual size used on the installed system
              will depend greatly on the filesystem used and its parameters,
              which might end up using either more or less space than the
              specified in this field.

              Additional disk space used when the package is installed. If
              this variable is set its value is added to that of the
              Installed-Size variable (whether set explicitly or using the
              default value) before it is copied into the Installed-Size
              control file field.

              The value of the source stanza field fieldname (which must be
              given in the canonical capitalisation; since dpkg 1.18.11).
              Setting these variables has no effect other than on places
              where they are expanded explicitly.  These variables are only
              available when generating binary control files.

              The value of the output field fieldname (which must be given
              in the canonical capitalisation). Setting these variables has
              no effect other than on places where they are expanded

       Format The .changes file format version generated by this version of
              the source packaging scripts. If you set this variable the
              contents of the Format field in the .changes file will change

       Newline, Space, Tab
              These variables each hold the corresponding character.

              Variable settings with names of this form are generated by

              The upstream version of dpkg (since dpkg 1.13.19).

              The full version of dpkg (since dpkg 1.13.19).

       If a variable is referred to but not defined it generates a warning
       and an empty value is assumed.

FILES         top

              List of substitution variables and values.

SEE ALSO         top

       dpkg(1), dpkg-genchanges(1), dpkg-gencontrol(1), dpkg-shlibdeps(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 2020-11-01.  (At
       that time, the date of the most recent commit that was found in the
       repository was 2020-07-08.)  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 im‐
       provements 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-substvars(5)

Pages that refer to this page: dpkg-genchanges(1)dpkg-gencontrol(1)dpkg-source(1)