SYNOPSIS
       substvars

DESCRIPTION
       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, hyphens and colons and start with an alphanu-
       meric. 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 $
       sign.

       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.

       Variables can be set using the -V common option. They can be also spec-
       ified 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 build architecture (from dpkg --print-architecture).

       source:Version
              The source package version.

       source:Upstream-Version
              The  upstream  source package version, including the Debian ver-
              sion epoch if any.

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

       Source-Version
              The source package version (from the changelog file). This vari-
              able is now deprecated as its  meaning  is  different  from  its
              function,  please  use  the  source:Version or binary:Version as
              appropriate.

       Installed-Size
              The total size of the package's installed files. This  value  is

       F:fieldname
              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 explicitly.

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

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

       shlibs:dependencyfield
              Variable settings with names  of  this  form  are  generated  by
              dpkg-shlibdeps.

       dpkg:Upstream-Version
              The upstream version of dpkg.

       dpkg:Version
              The full version of dpkg.

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

FILES
       debian/substvars
              List of substitution variables and values.

BUGS
       The point at which field overriding occurs compared to certain standard
       output field settings is rather confused.


SEE ALSO
       dpkg(1),   dpkg-genchanges(1),  dpkg-gencontrol(1),  dpkg-shlibdeps(1),
       dpkg-source(1).

AUTHOR
       Copyright (C) 1995-1996 Ian Jackson
       Copyright (C) 2000 Wichert Akkerman

       This is free software; see the GNU General Public Licence version 2  or
       later for copying conditions. There is NO WARRANTY.