# dpkg manual page - dpkg-deb(1)
#
# Copyright © 1995-1996 Ian Jackson <ijackson@chiark.greenend.org.uk>
# Copyright © 1999 Wichert Akkerman <wakkerma@debian.org>
# Copyright © 2006 Frank Lichtenheld <djpig@debian.org>
# Copyright © 2007-2015 Guillem Jover <guillem@debian.org>
#
# This is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

=encoding utf8

=head1 NAME

dpkg-deb - Debian package archive (.deb) manipulation tool

=head1 SYNOPSIS

B<dpkg-deb>
[I<option>...] I<command>

=head1 DESCRIPTION

B<dpkg-deb>
packs, unpacks and provides information about Debian archives.

Use
B<dpkg>
to install and remove packages from your system.

You can also invoke
B<dpkg-deb>
by calling
B<dpkg>
with whatever options you want to pass to
B<dpkg-deb>.
B<dpkg>
will spot that you wanted
B<dpkg-deb>
and run it for you.

For most commands taking an input archive argument, the archive can be
read from standard input if the archive name is given as a single minus
character («B<->»); otherwise lack of support will be documented in
their respective command description.

=head1 COMMANDS

=over

=item B<-b>, B<--build> I<binary-directory> [I<archive>|I<directory>]

Creates a debian archive from the filesystem tree stored in
I<binary-directory>.
I<binary-directory>
must have a
B<DEBIAN>
subdirectory, which contains the control information files such
as the control file itself.
This directory will
I<not>
appear in the binary package's filesystem archive, but instead
the files in it will be put in the binary package's control
information area.

Unless you specify
B<--no-check>, B<dpkg-deb>
will read
B<DEBIAN/control>
and parse it.
It will check the file for syntax errors and other problems,
and display the name of the binary package being built.
B<dpkg-deb>
will also check the permissions of the maintainer scripts and other
files found in the
B<DEBIAN>
control information directory.

If no
I<archive>
is specified then
B<dpkg-deb>
will write the package into the file
I<binary-directory>B<.deb>.

If the archive to be created already exists it will be overwritten.

If the second argument is a directory then
B<dpkg-deb>
will write to the file
I<directory>B</>I<package>B<_>I<version>B<_>I<arch>B<.deb.>
When a target directory is specified, rather than a file, the
B<--no-check>
option may not be used (since
B<dpkg-deb>
needs to read and parse the package control file to determine which
filename to use).

=item B<-I>, B<--info> I<archive> [I<control-file-name>...]

Provides information about a binary package archive.

If no
I<control-file-name>s
are specified then it will print a summary of the contents of the
package as well as its control file.

If any
I<control-file-name>s
are specified then
B<dpkg-deb>
will print them in the order they were specified; if any of the
components weren't present it will print an error message to stderr
about each one and exit with status 2.

=item B<-W>, B<--show> I<archive>

Provides information about a binary package archive in the format
specified by the
B<--showformat>
argument.
The default format displays the package's name and version
on one line, separated by a tabulator.

=item B<-f>, B<--field> I<archive> [I<control-field-name>...]

Extracts control file information from a binary package archive.

If no
I<control-field-name>s
are specified then it will print the whole control file.

If any are specified then
B<dpkg-deb>
will print their contents, in the order in which they appear in the
control file.
If more than one
I<control-field-name>
is specified then
B<dpkg-deb>
will precede each with its field name (and a colon and space).

No errors are reported for fields requested but not found.

=item B<-c>, B<--contents> I<archive>

Lists the contents of the filesystem tree archive portion of the
package archive.
It is currently produced in the format generated by
B<tar>'s
verbose listing.

=item B<-x>, B<--extract> I<archive> I<directory>

Extracts the filesystem tree from a package archive into the specified
directory.

Note that extracting a package to the root directory will
I<not>
result in a correct installation!
Use
B<dpkg>
to install packages.

I<directory>
(but not its parents) will be created if necessary, and its permissions
modified to match the contents of the package.

=item B<-X>, B<--vextract> I<archive> I<directory>

Is like
B<--extract> (B<-x>)
with
B<--verbose> (B<-v>)
which prints a listing of the files extracted as it goes.

=item B<-R>, B<--raw-extract> I<archive> I<directory>

Extracts the filesystem tree from a package archive into a specified
directory, and the control information files into a
B<DEBIAN>
subdirectory of the specified directory (since dpkg 1.16.1).

The target directory (but not its parents) will be created if necessary.

The input archive is not (currently) processed sequentially, so reading
it from standard input («B<->») is B<not> supported.

=item B<--ctrl-tarfile> I<archive>

Extracts the control data from a binary package and sends it to standard
output in
B<tar>
format (since dpkg 1.17.14).
Together with
L<tar(1)>
this can be used to extract a particular control file from a package archive.
The input archive will always be processed sequentially.

=item B<--fsys-tarfile> I<archive>

Extracts the filesystem tree data from a binary package and sends it
to standard output in
B<tar>
format.
Together with
L<tar(1)>
this can be used to extract a particular file from a package archive.
The input archive will always be processed sequentially.

=item B<-e>, B<--control> I<archive> [I<directory>]

Extracts the control information files from a package archive into the
specified directory.

If no directory is specified then a subdirectory
B<DEBIAN>
in the current directory is used.

The target directory (but not its parents) will be created if
necessary.

=item B<-?>, B<--help>

Show the usage message and exit.

=item B<--version>

Show the version and exit.

=back

=head1 OPTIONS

=over

=item B<--showformat=>I<format>

This option is used to specify the format of the output B<--show>
will produce.
The format is a string that will be output for each package
listed.

The string may reference any status field using the
“${I<field-name>}” form, a list of the valid fields can be easily
produced using
B<-I>
on the same package.
A complete explanation of the formatting options
(including escape sequences and field tabbing) can be found in the
explanation of the B<--showformat> option in
L<dpkg-query(1)>.

The default for this field is “${Package}\t${Version}\n”.

=item B<-z>, B<--compression-level=>I<compress-level>

Specify which compression level to use on the compressor backend, when
building a package (default is 9 for gzip, 6 for xz, 3 for zstd;
long option since dpkg 1.22.9).
The accepted values are compressor specific.
For gzip, from 0-9 with 0 being mapped to compressor none.
For xz from 0-9.
For zstd from 0-22, with levels from 20 to 22 enabling its ultra mode.
Before dpkg 1.16.2 level 0 was equivalent to compressor none for all
compressors.

=item B<-S>, B<--compression-strategy=>I<compress-strategy>

Specify which compression strategy to use on the compressor backend, when
building a package (since dpkg 1.16.2, long option since dpkg 1.22.9).
Allowed values are B<none> (since
dpkg 1.16.4), B<filtered>, B<huffman>, B<rle> and B<fixed> for
gzip (since dpkg 1.17.0) and B<extreme> for xz.

=item B<-Z>, B<--compression=>I<compress-type>

Specify which compression type to use when building a package
(long option since dpkg 1.22.9).
Allowed values are B<gzip>, B<xz> (since dpkg 1.15.6),
B<zstd> (since dpkg 1.21.18)
and B<none> (default is B<%DEB_DEFAULT_COMPRESSOR%>).

=item B<--[no-]uniform-compression>

Specify that the same compression parameters should be used for all archive
members (i.e. B<control.tar> and B<data.tar>; since dpkg 1.17.6).
Otherwise only the
B<data.tar> member will use those parameters.
The only supported
compression types allowed to be uniformly used are B<none>, B<gzip>,
B<xz> and B<zstd>.
The B<--no-uniform-compression> option disables uniform compression
(since dpkg 1.19.0).
Uniform compression is the default (since dpkg 1.19.0).

=item B<--threads-max=>I<threads>

Sets the maximum number of threads allowed for compressors that support
multi-threaded operations (since dpkg 1.21.9).

=item B<--root-owner-group>

Set the owner and group for each entry in the filesystem tree data to
root with id 0 (since dpkg 1.19.0).

B<Note>: This option can be useful for rootless builds (see
I<rootless-builds.txt>), but should B<not> be used when the
entries have an owner or group that is not root.
Support for these will be added later in the form of a meta manifest.

=item B<--deb-format=>I<format>

Set the archive format version used when building (since dpkg 1.17.0).
Allowed values are B<2.0> for the new format, and B<0.939000>
for the old one (default is B<2.0>).

The old archive format is less easily parsed by non-Debian tools and is
now obsolete; its only use is when building packages to be parsed by
versions of dpkg older than 0.93.76 (September 1995), which was released
as i386 a.out only.

=item B<--no-check>

Inhibits
B<dpkg-deb --build>'s
usual checks on the proposed contents of an archive.
You can build
any archive you want, no matter how broken, this way.

Option supported since dpkg 1.22.12.

=item B<--nocheck>

This is an alias for B<--no-check>.

=item B<-v>, B<--verbose>

Enables verbose output (since dpkg 1.16.1).
This currently only affects B<--extract> making it behave like
B<--vextract>.

=item B<-D>, B<--debug>

Enables debugging output.
This is not very interesting.

=back

=head1 EXIT STATUS

=over

=item B<0>

The requested action was successfully performed.

=item B<2>

Fatal or unrecoverable error due to invalid command-line usage, or
interactions with the system, such as accesses to the database,
memory allocations, etc.

=back

=head1 ENVIRONMENT

=over

=item B<DPKG_DEB_THREADS_MAX>

Sets the maximum number of threads allowed for compressors that support
multi-threaded operations (since dpkg 1.21.9).

The B<--threads-max> option overrides this value.

=item B<DPKG_DEB_COMPRESSOR_TYPE>

Sets the compressor type to use (since dpkg 1.21.10).

The B<-Z> option overrides this value.

=item B<DPKG_DEB_COMPRESSOR_LEVEL>

Sets the compressor level to use (since dpkg 1.21.10).

The B<-z> option overrides this value.

=item B<DPKG_COLORS>

Sets the color mode (since dpkg 1.18.5).
The currently accepted values are: B<auto> (default), B<always> and
B<never>.

=item B<DPKG_NLS>

If set, it will be used to decide whether to activate Native Language Support,
also known as internationalization (or i18n) support (since dpkg 1.22.7).
The accepted values are: B<0> and B<1> (default).

=item B<DPKG_PATH_PASSWD>

Sets the pathname for the system F<passwd> file.
This path is relative to the B<--root> directory.
The default is F</etc/passwd>.

Since dpkg 1.22.16.

=item B<DPKG_PATH_GROUP>

Sets the pathname for the system F<group> file.
This path is relative to the B<--root> directory.
The default is F</etc/group>.

Since dpkg 1.22.16.

=item B<TMPDIR>

If set, B<dpkg-deb> will use it as the directory in which to create
temporary files and directories.

=item B<SOURCE_DATE_EPOCH>

If set, it will be used as the timestamp (as seconds since the epoch) in
the L<deb(5)>'s L<ar(5)> container and used to clamp the mtime in
the L<tar(5)> file entries.

Since dpkg 1.18.8.

=back

=head1 NOTES

Do not attempt to use just
B<dpkg-deb>
to install software!
You must use
B<dpkg>
proper to ensure that all the files are correctly placed and the
package's scripts run and its status and contents recorded.

=head1 SECURITY

Examining untrusted package archives or extracting them into staging
directories should be considered a security boundary, and any breakage
of that boundary stemming from these operations should be considered a
security vulnerability.
But handling untrusted package archives should not be done lightly,
as the surface area includes any compression library supported,
in addition to the archive formats and control files themselves.
Performing these operations over untrusted data as root is strongly
discouraged.

Building package archives should only be performed over trusted data.

=head1 BUGS

B<dpkg-deb -I>
I<package1>B<.deb>
I<package2>B<.deb>
does the wrong thing.

There is no authentication on
B<.deb>
files; in fact, there isn't even a straightforward checksum.
(Higher level tools like APT support authenticating B<.deb> packages
retrieved from a given repository, and most packages nowadays provide an
md5sum control file generated by debian/rules.
Though this is not directly
supported by the lower level tools.)

=head1 SEE ALSO

F<%PKGDOCDIR%/spec/rootless-builds.txt>,
L<deb(5)>,
L<deb-control(5)>,
L<dpkg(1)>,
L<dselect(1)>.
