deb-substvars

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

NAME
       deb-substvars - Debian source substitution variables

SYNOPSIS
       debian/substvars, debian/binary-package.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 (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 $
       sign.  This can be used as an escape sequence such as ${}{VARIABLE}
       which will end up as ${VARIABLE} on the output.

       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).

       vendor:Name
           The current vendor name (since dpkg 1.20.0).  This value comes from
           the Vendor field for the current vendor's origin file, as dpkg-
           vendor(1) would retrieve it.

       vendor:Id
           The current vendor ID (since dpkg 1.20.0).  This is just the
           lowercase variant of vendor:Name.

       source:Version
           The source package version (since dpkg 1.13.19).

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

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

       Source-Version
           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.

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

       source:Extended-Description
           The source package extended description, extracted from the source
           stanza Description field, if it exists (since dpkg 1.19.0).

       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.  With
           hardlinks only being counted once as a regular file.

           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.

       S:fieldname
           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.

       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 (since dpkg 1.13.19).

       dpkg:Version
           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
       debian/substvars
           List of substitution variables and values.

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

1.21.1                            2024-02-23                  deb-substvars(5)