dpkg(1) dpkg suite dpkg(1)
dpkg - package manager for Debian
dpkg [options] action
This manual is intended for users wishing to understand dpkg's command line options and
package states in more detail than that provided by dpkg --help.
It should not be used by package maintainers wishing to understand how dpkg will install
their packages. The descriptions of what dpkg does when installing and removing packages
are particularly inadequate.
dpkg is a tool to install, build, remove and manage Debian packages. The primary and more
user-friendly front-end for dpkg is aptitude(1). dpkg itself is controlled entirely via
command line parameters, which consist of exactly one action and zero or more options. The
action-parameter tells dpkg what to do and options control the behavior of the action in
dpkg can also be used as a front-end to dpkg-deb(1). The following are dpkg-deb actions,
and if they are encountered, dpkg just runs dpkg-deb with the parameters given to it:
-X, --vextract, and
Please refer to dpkg-deb(1) for information about these actions.
INFORMATION ABOUT PACKAGES
dpkg maintains some usable information about available packages. The information is
divided in three classes: states, selection states and flags. These values are intended to
be changed mainly with dselect.
The package is not installed on your system.
Only the configuration files of the package exist on the system.
The installation of the package has been started, but not completed for some rea-
The package is unpacked, but not configured.
The package is unpacked and configuration has been started, but not yet completed
for some reason.
The package awaits trigger processing by another package.
The package has been triggered.
The package is unpacked and configured OK.
PACKAGE SELECTION STATES
The package is selected for installation.
hold A package marked to be on hold is not handled by dpkg, unless forced to do that
with option --force-hold.
The package is selected for deinstallation (i.e. we want to remove all files,
except configuration files).
purge The package is selected to be purged (i.e. we want to remove everything from system
directories, even configuration files).
A package marked reinst-required is broken and requires reinstallation. These pack-
ages cannot be removed, unless forced with option --force-remove-reinstreq.
-i, --install package_file...
Install the package. If --recursive or -R option is specified, package_file must
refer to a directory instead.
Installation consists of the following steps:
1. Extract the control files of the new package.
2. If another version of the same package was installed before the new installa-
tion, execute prerm script of the old package.
3. Run preinst script, if provided by the package.
4. Unpack the new files, and at the same time back up the old files, so that if
something goes wrong, they can be restored.
5. If another version of the same package was installed before the new installa-
tion, execute the postrm script of the old package. Note that this script is exe-
cuted after the preinst script of the new package, because new files are written at
the same time old files are removed.
6. Configure the package. See --configure for detailed information about how this
Unpack the package, but don't configure it. If --recursive or -R option is speci-
fied, package_file must refer to a directory instead.
Configure a package which has been unpacked but not yet configured. If -a or
--pending is given instead of package, all unpacked but unconfigured packages are
To reconfigure a package which has already been configured, try the dpkg-reconfig-
ure(8) command instead.
Configuring consists of the following steps:
1. Unpack the conffiles, and at the same time back up the old conffiles, so that
they can be restored if something goes wrong.
2. Run postinst script, if provided by the package.
Processes only triggers. All pending triggers will be processed. If package names
are supplied only those packages' triggers will be processed, exactly once each
where necessary. Use of this option may leave packages in the improper trig-
gers-awaited and triggers-pending states. This can be fixed later by running: dpkg
-r, --remove, -P, --purge package...|-a|--pending
Remove an installed package. -r or --remove remove everything except conffiles.
This may avoid having to reconfigure the package if it is reinstalled later. (Conf-
files are configuration files that are listed in the DEBIAN/conffiles control
file). -P or --purge removes everything, including conffiles. If -a or --pending is
given instead of a package name, then all packages unpacked, but marked to be
removed or purged in file /var/lib/dpkg/status, are removed or purged, respec-
tively. Note: some configuration files might be unknown to dpkg because they are
created and handled separately through the configuration scripts. In that case,
dpkg won't remove them by itself, but the package's postrm script (which is called
by dpkg), has to take care of their removal during purge. Of course, this only
applies to files in system directories, not configuration files written to individ-
ual users' home directories.
Removing of a package consists of the following steps:
1. Run prerm script
2. Remove the installed files
3. Run postrm script
--update-avail, --merge-avail Packages-file
Update dpkg's and dselect's idea of which packages are available. With action
--merge-avail, old information is combined with information from Packages-file.
With action --update-avail, old information is replaced with the information in the
Packages-file. The Packages-file distributed with Debian is simply named Packages.
dpkg keeps its record of available packages in /var/lib/dpkg/available.
A simpler one-shot command to retrieve and update the available file is dselect
update. Note that this file is mostly useless if you don't use dselect but an APT-
based frontend: APT has its own system to keep track of available packages.
-A, --record-avail package_file...
Update dpkg and dselect's idea of which packages are available with information
from the package package_file. If --recursive or -R option is specified, pack-
age_file must refer to a directory instead.
Now obsolete and a no-op as dpkg will automatically forget uninstalled unavailable
Erase the existing information about what packages are available.
Searches for packages that have been installed only partially on your system. dpkg
will suggest what to do with them to get them working.
Get list of package selections, and write it to stdout. Without a pattern, non-
installed packages (i.e. those which have been previously purged) will not be
Set package selections using file read from stdin. This file should be in the for-
mat '<package> <state>', where state is one of install, hold, deinstall or purge.
Blank lines and comment lines beginning with '#' are also permitted.
Set the requested state of every non-essential package to deinstall. This is
intended to be used immediately before --set-selections, to deinstall any packages
not in list given to --set-selections.
Searches for packages selected for installation, but which for some reason still
haven't been installed.
Print architecture of packages dpkg installs (for example, "i386").
Add architecture to the list of architectures for which packages can be
installed without using --force-architecture, in addition to the architec-
ture dpkg is built for (i.e.: the output of --print-architecture).
Print a space-separated list of the extra architectures dpkg is configured
to allow packages to be installed for.
--compare-versions ver1 op ver2
Compare version numbers, where op is a binary operator. dpkg returns success
(zero result) if the specified condition is satisfied, and failure (nonzero
result) otherwise. There are two groups of operators, which differ in how
they treat an empty ver1 or ver2. These treat an empty version as earlier
than any version: lt le eq ne ge gt. These treat an empty version as later
than any version: lt-nl le-nl ge-nl gt-nl. These are provided only for com-
patibility with control file syntax: < << <= = >= >> >.
Accept a series of commands on input file descriptor <n>. Note: additional
options set on the command line, and through this file descriptor, are not
reset for subsequent commands executed during the same run.
--help Display a brief help message.
Give help about the --force-thing options.
Give help about debugging options.
Display dpkg version information.
See dpkg-deb(1) for more information about the following actions.
-b, --build directory [archive|directory]
Build a deb package.
-c, --contents archive
List contents of a deb package.
-e, --control filename [directory]
Extract control-information from a package.
-x, --extract archive directory
Extract the files contained by package.
-X, --vextract archive directory
Extract and display the filenames contained by a
-f, --field archive [control-field...]
Display control field(s) of a package.
Display the filesystem tar-file contained by a
-I, --info archive [control-file...]
Show information about a package.
See dpkg-query(1) for more information about the following actions.
-l, --list package-name-pattern...
List packages matching given pattern.
-s, --status package-name...
Report status of specified package.
-L, --listfiles package-name...
List files installed to your system from package-name.
-S, --search filename-search-pattern...
Search for a filename from installed packages.
-p, --print-avail package-name...
Display details about package-name, as found in
/var/lib/dpkg/available. Users of APT-based frontends
should use apt-cache show package-name instead.
All options can be specified both on the command line and in the dpkg configuration
file /etc/dpkg/dpkg.cfg or the files on the configuration directory
/etc/dpkg/dpkg.cfg.d/. Each line in the configuration file is either an option
(exactly the same as the command line option but without leading dashes) or a com-
ment (if it starts with a #).
Change after how many errors dpkg will abort. The default is 50.
When a package is removed, there is a possibility that another installed
package depended on the removed package. Specifying this option will cause
automatic deconfiguration of the package which depended on the removed pack-
Switch debugging on. octal is formed by bitwise-orring desired values
together from the list below (note that these values may change in future
releases). -Dh or --debug=help display these debugging values.
1 Generally helpful progress information
2 Invocation and status of maintainer scripts
10 Output for each file processed
100 Lots of output for each file processed
20 Output for each configuration file
200 Lots of output for each configuration file
40 Dependencies and conflicts
400 Lots of dependencies/conflicts output
10000 Trigger activation and processing
20000 Lots of output regarding triggers
40000 Silly amounts of output regarding triggers
1000 Lots of drivel about e.g. the dpkg/info dir
2000 Insane amounts of drivel
--force-things, --no-force-things, --refuse-things
Force or refuse (no-force and refuse mean the same thing) to do some things.
things is a comma separated list of things specified below. --force-help
displays a message describing them. Things marked with (*) are forced by
Warning: These options are mostly intended to be used by experts only. Using
them without fully understanding their effects may break your whole system.
all: Turns on (or off) all force options.
downgrade(*): Install a package, even if newer version of it is already
Warning: At present dpkg does not do any dependency checking on downgrades
and therefore will not warn you if the downgrade breaks the dependency of
some other package. This can have serious side effects, downgrading essen-
tial system components can even make your whole system unusable. Use with
configure-any: Configure also any unpacked but unconfigured packages on
which the current package depends.
hold: Process packages even when marked "hold".
remove-reinstreq: Remove a package, even if it's broken and marked to
require reinstallation. This may, for example, cause parts of the package to
remain on the system, which will then be forgotten by dpkg.
remove-essential: Remove, even if the package is considered essential.
Essential packages contain mostly very basic Unix commands. Removing them
might cause the whole system to stop working, so use with caution.
depends: Turn all dependency problems into warnings.
depends-version: Don't care about versions when checking dependencies.
breaks: Install, even if this would break another package.
conflicts: Install, even if it conflicts with another package. This is dan-
gerous, for it will usually cause overwriting of some files.
confmiss: Always install a missing conffile. This is dangerous, since it
means not preserving a change (removing) made to the file.
confnew: If a conffile has been modified always install the new version
without prompting, unless the --force-confdef is also specified, in which
case the default action is preferred.
confold: If a conffile has been modified always keep the old version without
prompting, unless the --force-confdef is also specified, in which case the
default action is preferred.
confdef: If a conffile has been modified always choose the default action.
If there is no default action it will stop to ask the user unless
--force-confnew or --force-confold is also been given, in which case it will
use that to decide the final action.
confask: If a conffile has been modified always offer to replace it with the
version in the package, even if the version in the package did not change.
If any of --force-confmiss, --force-confnew, --force-confold, or
--force-confdef is also given, it will be used to decide the final action.
overwrite: Overwrite one package's file with another's file.
overwrite-dir Overwrite one package's directory with another's file.
overwrite-diverted: Overwrite a diverted file with an undiverted version.
unsafe-io: Do not perform safe I/O operations when unpacking. Currently this
implies not performing file system syncs before file renames, which is known
to cause substantial performance degradation on some file systems, unfortu-
nately the ones that require the safe I/O on the first place due to their
unreliable behaviour causing zero-length files on abrupt system crashes.
Note: For ext4, the main offender, consider using instead the mount option
nodelalloc, which will fix both the performance degradation and the data
safety issues, the latter by making the file system not produce zero-length
files on abrupt system crashes with any software not doing syncs before
Warning: Using this option might improve performance at the cost of losing
data, use with care.
architecture: Process even packages with wrong or no architecture.
bad-path: PATH is missing important programs, so problems are likely.
not-root: Try to (de)install things even when not root.
bad-verify: Install a package even if it fails authenticity check.
Ignore dependency-checking for specified packages (actually, checking is
performed, but only warnings about conflicts are given, nothing else).
Select new or old binary package format. This is a dpkg-deb(1) option.
Don't read or check contents of control file while building a package. This
is a dpkg-deb(1) option.
--no-act, --dry-run, --simulate
Do everything which is supposed to be done, but don't write any changes.
This is used to see what would happen with the specified action, without
actually modifying anything.
Be sure to give --no-act before the action-parameter, or you might end up
with undesirable results. (e.g. dpkg --purge foo --no-act will first purge
package foo and then try to purge package --no-act, even though you probably
expected it to actually do nothing)
Recursively handle all regular files matching pattern *.deb found at speci-
fied directories and all of its subdirectories. This can be used with -i,
-A, --install, --unpack and --avail actions.
-G Don't install a package if a newer version of the same package is already
installed. This is an alias of --refuse-downgrade.
Change default administrative directory, which contains many files that give
information about status of installed or uninstalled packages, etc.
(Defaults to /var/lib/dpkg)
Change default installation directory which refers to the directory where
packages are to be installed. instdir is also the directory passed to
chroot(2) before running package's installation scripts, which means that
the scripts see instdir as a root directory. (Defaults to /)
Changing root changes instdir to dir and admindir to dir/var/lib/dpkg.
Only process the packages that are selected for installation. The actual
marking is done with dselect or by dpkg, when it handles packages. For exam-
ple, when a package is removed, it will be marked selected for deinstalla-
Don't install the package if the same version of the package is already
Set an invoke hook command to be run via "sh -c" before or after the dpkg
run for the unpack, configure, install, triggers-only, remove and purge dpkg
actions. This option can be specified multiple times. The order the options
are specified is preserved, with the ones from the configuration files tak-
ing precedence. The environment variable DPKG_HOOK_ACTION is set for the
hooks to the current dpkg action. Note: front-ends might call dpkg several
times per invocation, which might run the hooks more times than expected.
Set glob-pattern as a path filter, either by excluding or re-including pre-
viously excluded paths matching the specified patterns during install.
Warning: take into account that depending on the excluded paths you might
completely break your system, use with caution.
The glob patterns use the same wildcards used in the shell, were '*' matches
any sequence of characters, including the empty string and also '/'. For
example, '/usr/*/READ*' matches '/usr/share/doc/package/README'. As usual,
'?' matches any single character (again, including '/'). And '[' starts a
character class, which can contain a list of characters, ranges and comple-
mentations. See glob(7) for detailed information about globbing. Note: the
current implementation might re-include more directories and symlinks than
needed, to be on the safe side and avoid possible unpack failures, future
work might fix this.
This can be used to remove all paths except some particular ones; a typical
to remove all documentation files except the copyright files.
These two options can be specified multiple times, and interleaved with each
other. Both are processed in the given order, with the last rule that
matches a file name making the decision.
Send machine-readable package status and progress information to file
descriptor n. This option can be specified multiple times. The information
is generally one record per line, in one of the following forms:
status: package: status
Package status changed; status is as in the status file.
status: package : error : extended-error-message
An error occurred. Any possible newlines in extended-error-message
will be converted to spaces before output.
status: file : conffile-prompt : 'real-old' 'real-new' useredited distedited
User is being asked a conffile question.
processing: stage: package
Sent just before a processing stage starts. stage is one of upgrade,
install (both sent before unpacking), configure, trigproc, disappear,
Send machine-readable package status and progress information to the shell
command's standard input. This option can be specified multiple times. The
output format used is the same as in --status-fd.
Log status change updates and actions to filename, instead of the default
/var/log/dpkg.log. If this option is given multiple times, the last filename
is used. Log messages are of the form `YYYY-MM-DD HH:MM:SS status <state>
<pkg> <installed-version>' for status change updates; `YYYY-MM-DD HH:MM:SS
<action> <pkg> <installed-version> <available-version>' for actions where
<action> is one of install, upgrade, remove, purge; and `YYYY-MM-DD HH:MM:SS
conffile <filename> <decision>' for conffile changes where <decision> is
either install or keep.
Do not try to verify package signatures.
Do not run any triggers in this run (activations will still be recorded).
If used with --configure package or --triggers-only package then the named
package postinst will still be run even if only a triggers run is needed.
Use of this option may leave packages in the improper triggers-awaited and
triggers-pending states. This can be fixed later by running: dpkg --config-
Cancels a previous --no-triggers.
Configuration file with default options.
Default log file (see /etc/dpkg/dpkg.cfg(5) and option --log).
The other files listed below are in their default directories, see option
--admindir to see how to change locations of these files.
List of available packages.
Statuses of available packages. This file contains information about whether
a package is marked for removing or not, whether it is installed or not,
etc. See section INFORMATION ABOUT PACKAGES for more info.
The status file is backed up daily in /var/backups. It can be useful if it's
lost or corrupted due to filesystems troubles.
The following files are components of a binary package. See deb(5) for more infor-
mation about them:
HOME If set, dpkg will use it as the directory from which to read the user spe-
cific configuration file.
TMPDIR If set, dpkg will use it as the directory in which to create temporary files
PAGER The program dpkg will execute when displaying the conffiles.
SHELL The program dpkg will execute when starting a new shell.
Sets the number of columns dpkg should use when displaying formatted text.
Currently only used by -l.
Defined by dpkg on the shell spawned on the conffile prompt to examine the
situation. Current valid value: conffile-prompt.
Defined by dpkg on the shell spawned on the conffile prompt to examine the
situation. Contains the path to the old conffile.
Defined by dpkg on the shell spawned on the conffile prompt to examine the
situation. Contains the path to the new conffile.
Defined by dpkg on the maintainer script environment to the version of the
currently running dpkg instance.
Defined by dpkg on the maintainer script environment to the package name
Defined by dpkg on the maintainer script environment to the architecture the
package got built for.
Defined by dpkg on the maintainer script environment to the name of the
script running (preinst, postinst, prerm, postrm).
To list packages related to the editor vi(1):
dpkg -l '*vi*'
To see the entries in /var/lib/dpkg/available of two packages:
dpkg --print-avail elvis vim | less
To search the listing of packages yourself:
To remove an installed elvis package:
dpkg -r elvis
To install a package, you first need to find it in an archive or CDROM. The "avail-
able" file shows that the vim package is in section "editors":
dpkg -i vim_4.5-3.deb
To make a local copy of the package selection states:
dpkg --get-selections >myselections
You might transfer this file to another computer, and install it there with:
dpkg --set-selections <myselections
Note that this will not actually install or remove anything, but just set the
selection state on the requested packages. You will need some other application to
actually download and install the requested packages. For example, run apt-get dse-
Ordinarily, you will find that dselect(1) provides a more convenient way to modify
the package selection states.
Additional functionality can be gained by installing any of the following packages:
apt, aptitude and debsums.
aptitude(1), apt(1), dselect(1), dpkg-deb(1), dpkg-query(1), deb(5), deb-con-
trol(5), dpkg.cfg(5), and dpkg-reconfigure(8).
--no-act usually gives less information than might be helpful.
See /usr/share/doc/dpkg/THANKS for the list of people who have contributed to dpkg.
Debian Project 2011-02-05 dpkg(1)