deb-substvars(5) dpkg suite deb-substvars(5)
deb-substvars - Debian source substitution variables
substvars
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 (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.
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.
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.
debian/substvars
List of substitution variables and values.
dpkg(1), dpkg-genchanges(1), dpkg-gencontrol(1), dpkg-shlibdeps(1),
dpkg-source(1).
This page is part of the dpkg (Debian Package Manager) project.
Information about the project can be found at
⟨https://wiki.debian.org/Teams/Dpkg/⟩. If you have a bug report for
this manual page, see
⟨http://bugs.debian.org/cgi-bin/pkgreport.cgi?src=dpkg⟩. This page
was obtained from the project's upstream Git repository
⟨git://git.debian.org/git/dpkg/dpkg.git⟩ on 2017-07-05. If you dis‐
cover 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 man-pages@man7.org
1.18.15-3-ga2ef 1970-01-01 deb-substvars(5)
Pages that refer to this page: dpkg-genchanges(1), dpkg-gencontrol(1), dpkg-source(1)