Provided by: dpkg_1.17.5ubuntu5.8_amd64 
NAME
dpkg - package manager for Debian
SYNOPSIS
dpkg [option...] action
WARNING
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.
DESCRIPTION
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 some way.
dpkg can also be used as a front-end to dpkg-deb(1) and dpkg-query(1). The list of supported actions can
be found later on in the ACTIONS section. If any such action is encountered dpkg just runs dpkg-deb or
dpkg-query with the parameters given to it, but no specific options are currently passed to them, to use
any such option the back-ends need to be called directly.
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.
Package states
not-installed
The package is not installed on your system.
config-files
Only the configuration files of the package exist on the system.
half-installed
The installation of the package has been started, but not completed for some reason.
unpacked
The package is unpacked, but not configured.
half-configured
The package is unpacked and configuration has been started, but not yet completed for some reason.
triggers-awaited
The package awaits trigger processing by another package.
triggers-pending
The package has been triggered.
installed
The package is unpacked and configured OK.
Package selection states
install
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.
deinstall
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).
Package flags
reinst-required
A package marked reinst-required is broken and requires reinstallation. These packages cannot be
removed, unless forced with option --force-remove-reinstreq.
ACTIONS
-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 installation, 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 installation, execute the
postrm script of the old package. Note that this script is executed 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 is done.
--unpack package-file...
Unpack the package, but don't configure it. If --recursive or -R option is specified, package-file
must refer to a directory instead.
--configure package...|-a|--pending
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 configured.
To reconfigure a package which has already been configured, try the dpkg-reconfigure(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.
--triggers-only package...|-a|--pending
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 triggers-awaited and triggers-pending states. This can
be fixed later by running: dpkg --configure --pending.
-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. (Conffiles 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, respectively.
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 individual 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
-V, --verify [package-name...]
Verifies the integrity of package-name or all packages if omitted, by comparing information from
the installed paths with the database metadata.
The output format is selectable with the --verify-format option, which by default uses the rpm
format, but that might change in the future, and as such programs parsing this command output
should be explicit about the format they expect.
--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, package-file must refer to a directory
instead.
--forget-old-unavail
Now obsolete and a no-op as dpkg will automatically forget uninstalled unavailable packages.
--clear-avail
Erase the existing information about what packages are available.
-C, --audit
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-selections [package-name-pattern...]
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 shown.
--set-selections
Set package selections using file read from stdin. This file should be in the format 'package
state', where state is one of install, hold, deinstall or purge. Blank lines and comment lines
beginning with '#' are also permitted.
The available file needs to be up-to-date for this command to be useful, otherwise unknown
packages will be ignored with a warning. See the --update-avail and --merge-avail commands for
more information.
--clear-selections
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.
--yet-to-unpack
Searches for packages selected for installation, but which for some reason still haven't been
installed.
--add-architecture architecture
Add architecture to the list of architectures for which packages can be installed without using
--force-architecture. The architecture dpkg is built for (i.e. the output of --print-architecture)
is always part of that list.
--remove-architecture architecture
Remove architecture from the list of architectures for which packages can be installed without
using --force-architecture. If the architecture is currently in use in the database then the
operation will be refused, except if --force-architecture is specified. The architecture dpkg is
built for (i.e. the output of --print-architecture) can never be removed from that list.
--print-architecture
Print architecture of packages dpkg installs (for example, "i386").
--print-foreign-architectures
Print a newline-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 compatibility with control file
syntax: < << <= = >= >> >.
-?, --help
Display a brief help message.
--force-help
Give help about the --force-thing options.
-Dh, --debug=help
Give help about debugging options.
--version
Display dpkg version information.
dpkg-deb actions
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
package.
-f, --field archive [control-field...]
Display control field(s) of a package.
--fsys-tarfile archive
Display the filesystem tar-file contained by a
Debian package.
-I, --info archive [control-file...]
Show information about a package.
dpkg-query actions
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.
OPTIONS
All options can be specified both on the command line and in the dpkg configuration file
/etc/dpkg/dpkg.cfg or fragment files (with names matching this shell pattern '[0-9a-zA-Z_-]*') 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 hyphens) or a comment (if it starts with
a #).
--abort-after=number
Change after how many errors dpkg will abort. The default is 50.
-B, --auto-deconfigure
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 package.
-Doctal, --debug=octal
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.
Number Description
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 default.
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 installed.
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 essential system components can even make your whole system unusable. Use
with care.
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 dangerous, for it will
usually cause overwriting of some files.
confmiss: If a conffile is missing and the version in the package did change, always install the
missing conffile without prompting. This is dangerous, since it means not preserving a change
(removing) made to the file.
confnew: If a conffile has been modified and the version in the package did change, 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 and the version in the package did change, 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 and the version in the package did change, always choose
the default action without prompting. 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, unfortunately 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 atomic renames.
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-version: Process even packages with wrong versions.
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-depends=package,...
Ignore dependency-checking for specified packages (actually, checking is performed, but only
warnings about conflicts are given, nothing else).
--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)
-R, --recursive
Recursively handle all regular files matching pattern *.deb found at specified 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.
--admindir=dir
Change default administrative directory, which contains many files that give information about
status of installed or uninstalled packages, etc. (Defaults to /var/lib/dpkg)
--instdir=dir
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 /)
--root=dir
Changing root changes instdir to dir and admindir to dir/var/lib/dpkg.
-O, --selected-only
Only process the packages that are selected for installation. The actual marking is done with
dselect or by dpkg, when it handles packages. For example, when a package is removed, it will be
marked selected for deinstallation.
-E, --skip-same-version
Don't install the package if the same version of the package is already installed.
--pre-invoke=command
--post-invoke=command
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 taking 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.
--path-exclude=glob-pattern
--path-include=glob-pattern
Set glob-pattern as a path filter, either by excluding or re-including previously 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
complementations. 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 case is:
--path-exclude=/usr/share/doc/*
--path-include=/usr/share/doc/*/copyright
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.
--verify-format format-name
Sets the output format for the --verify command.
The only currently supported output format is rpm, which consists of a line for every path that
failed any check. The lines start with 9 characters to report the specific check results, a '?'
implies the check could not be done (lack of support, file permissions, etc), '.' implies the
check passed, and an alphanumeric character implies a specific check failed; the only functional
check is an md5sum verification denoted with a '5' on the third character. The line is followed by
a space and an attribute character (currently 'c' for conffiles), another space and the pathname.
--status-fd n
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, remove, purge.
--status-logger=command
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=filename
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.
--no-debsig
Do not try to verify package signatures.
--no-triggers
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 --configure
--pending.
--triggers
Cancels a previous --no-triggers.
ENVIRONMENT
HOME If set, dpkg will use it as the directory from which to read the user specific configuration file.
TMPDIR If set, dpkg will use it as the directory in which to create temporary files and directories.
PAGER The program dpkg will execute when displaying the conffiles.
SHELL The program dpkg will execute when starting a new shell.
COLUMNS
Sets the number of columns dpkg should use when displaying formatted text. Currently only used by
-l.
DPKG_SHELL_REASON
Defined by dpkg on the shell spawned on the conffile prompt to examine the situation. Current
valid value: conffile-prompt.
DPKG_CONFFILE_OLD
Defined by dpkg on the shell spawned on the conffile prompt to examine the situation. Contains the
path to the old conffile.
DPKG_CONFFILE_NEW
Defined by dpkg on the shell spawned on the conffile prompt to examine the situation. Contains the
path to the new conffile.
DPKG_RUNNING_VERSION
Defined by dpkg on the maintainer script environment to the version of the currently running dpkg
instance.
DPKG_MAINTSCRIPT_PACKAGE
Defined by dpkg on the maintainer script environment to the (non-arch-qualified) package name
being handled.
DPKG_MAINTSCRIPT_PACKAGE_REFCOUNT
Defined by dpkg on the maintainer script environment to the package reference count, i.e. the
number of package instances with a state greater than not-installed. Since dpkg 1.17.2.
DPKG_MAINTSCRIPT_ARCH
Defined by dpkg on the maintainer script environment to the architecture the package got built
for.
DPKG_MAINTSCRIPT_NAME
Defined by dpkg on the maintainer script environment to the name of the script running (preinst,
postinst, prerm, postrm).
FILES
/etc/dpkg/dpkg.cfg.d/[0-9a-zA-Z_-]*
Configuration fragment files.
/etc/dpkg/dpkg.cfg
Configuration file with default options.
/var/log/dpkg.log
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.
/var/lib/dpkg/available
List of available packages.
/var/lib/dpkg/status
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 information about them:
control
conffiles
preinst
postinst
prerm
postrm
triggers
BUGS
--no-act usually gives less information than might be helpful.
EXAMPLES
To list installed packages related to the editor vi(1) (note that dpkg-query does not load the available
file anymore by default, and the dpkg-query --load-avail option should be used instead for that):
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:
less /var/lib/dpkg/available
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 available file shows that the
vim package is in section "editors":
cd /media/cdrom/pool/main/v/vim
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 after having updated the available file there with
your package manager frontend of choice (see https://wiki.debian.org/Teams/Dpkg/FAQ for more details),
for example:
avail=`mktemp`
apt-cache dumpavail >"$avail"
dpkg --merge-avail "$avail"
rm "$avail"
you can install it with:
dpkg --clear-selections
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 dselect-upgrade.
Ordinarily, you will find that dselect(1) provides a more convenient way to modify the package selection
states.
ADDITIONAL FUNCTIONALITY
Additional functionality can be gained by installing any of the following packages: apt, aptitude and
debsums.
SEE ALSO
aptitude(1), apt(1), dselect(1), dpkg-deb(1), dpkg-query(1), deb(5), deb-control(5), dpkg.cfg(5), and
dpkg-reconfigure(8).
AUTHORS
See /usr/share/doc/dpkg/THANKS for the list of people who have contributed to dpkg.