|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
|
deb-substvars(5) dpkg suite deb-substvars(5)
deb-substvars - Debian source substitution variables
debian/substvars, debian/binary-package.substvars, variables
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.
Variable Syntax
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.
File Syntax
Substitution variables can be specified in a file. These files
consist of lines of the form name=value, name?=value, or
name!=value. The = operator assigns a normal substitution
variable, the ?= operator (since dpkg 1.21.8) assigns an optional
substitution variable which will emit no warnings even if unused,
and the != operator (since dpkg 1.22.7) assigns a required
substitution variable which will error out if unused. Trailing
whitespace on each line, blank lines, and lines starting with a #
symbol (comments) are ignored.
Substitution
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 common option).
After all the substitutions have been done each occurrence of the
string ${} (which is not an actual substitution variable) 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.
If a variable is referred to but not defined it generates a
warning and an empty value is assumed.
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.
Built-in Variable
Additionally, the following standard variables are always
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:field-name
The value of the source stanza field field-name (which must be
given in the canonical capitalization; 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:field-name
The value of the output field field-name (which must be given
in the canonical capitalization). 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).
debian/substvars
List of substitution variables and values.
dpkg(1), dpkg-vendor(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
clone https://git.dpkg.org/git/dpkg/dpkg.git⟩ on 2025-08-11. (At
that time, the date of the most recent commit that was found in
the repository was 2025-08-06.) 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 improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
1.22.12-10-g32fee 2025-01-01 deb-substvars(5)
Pages that refer to this page: dpkg-genchanges(1), dpkg-gencontrol(1), dpkg-shlibdeps(1), dpkg-source(1), deb-control(5)
|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|