deb-substvars(5)

NAME

   deb-substvars - Debian source substitution variables

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
   alphanumeric. 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.

   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
     ${Description}
     .
     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).

   source:Version
          The source package version.

   source:Upstream-Version
          The  upstream  source  package  version,  including  the  Debian
          version 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
          variable is now deprecated as its meaning is different from  its
          function,  please  use  the  source:Version or binary:Version as
          appropriate.

   Installed-Size
          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.

   Extra-Size
          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.

   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
          contents 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.

SEE ALSO

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

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