dpkg(1)
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 correctly unpacked and configured.
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
ok A package marked ok is in a known state, but might need further
processing.
reinstreq
A package marked reinstreq 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 (since dpkg 1.14.17). 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 package...|-a|--pending
Remove an installed package. This removes everything except
conffiles, which 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). If -a or
--pending is given instead of a package name, then all packages
unpacked, but marked to be removed in file /var/lib/dpkg/status,
are removed.
Removing of a package consists of the following steps:
1. Run prerm script
2. Remove the installed files
3. Run postrm script
-P, --purge package...|-a|--pending
Purge an installed or already removed package. This removes
everything, including conffiles. If -a or --pending is given
instead of a package name, then all packages unpacked or
removed, but marked to be purged in file /var/lib/dpkg/status,
are purged.
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.
Purging of a package consists of the following steps:
1. Remove the package, if not already removed. See --remove for
detailed information about how this is done.
2. Run postrm script.
-V, --verify [package-name...]
Verifies the integrity of package-name or all packages if
omitted, by comparing information from the files installed by a
package with the files metadata information stored in the dpkg
database (since dpkg 1.17.2). The origin of the files metadata
information in the database is the binary packages themselves.
That metadata gets collected at package unpack time during the
installation process.
Currently the only functional check performed is an md5sum
verification of the file contents against the stored value in
the files database. It will only get checked if the database
contains the file md5sum. To check for any missing metadata in
the database, the --audit command can be used.
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.
-C, --audit [package-name...]
Performs database sanity and consistency checks for package-name
or all packages if omitted (per package checks since dpkg
1.17.10). For example, searches for packages that have been
installed only partially on your system or that have missing,
wrong or obsolete control data or files. dpkg will suggest what
to do with them to get them fixed.
--update-avail [Packages-file]
--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. If the Packages-file argument is
missing or named - then it will be read from standard input
(since dpkg 1.17.7). 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 (since dpkg 1.15.4), but only
those that do not contain user information such as package
selections.
--clear-avail
Erase the existing information about what packages are
available.
--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 (since dpkg 1.13.18). 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.
--predep-package
Print a single package which is the target of one or more
relevant pre-dependencies and has itself no unsatisfied pre-
dependencies.
If such a package is present, output it as a Packages file
entry, which can be massaged as appropriate.
Returns 0 when a package is printed, 1 when no suitable package
is available and 2 on error.
--add-architecture architecture
Add architecture to the list of architectures for which packages
can be installed without using --force-architecture (since dpkg
1.16.2). 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
(since dpkg 1.16.2). 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 (since dpkg
1.16.2).
--assert-feature
Asserts that dpkg supports the requested feature. Returns 0 if
the feature is fully supported, 1 if the feature is known but
dpkg cannot provide support for it yet, and 2 if the feature is
unknown. The current list of assertable features is:
support-predepends
Supports the Pre-Depends field (since dpkg 1.1.0).
working-epoch
Supports epochs in version strings (since dpkg 1.4.0.7).
long-filenames
Supports long filenames in deb(5) archives (since dpkg
1.4.1.17).
multi-conrep
Supports multiple Conflicts and Replaces (since dpkg
1.4.1.19).
multi-arch
Supports multi-arch fields and semantics (since dpkg
1.16.2).
versioned-provides
Supports versioned Provides (since dpkg 1.17.11).
--compare-versions ver1 op ver2
Compare version numbers, where op is a binary operator. dpkg
returns true (0) if the specified condition is satisfied, and
false (1) 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: < << <= = >= >> >. The < and >
operators are obsolete and should not be used, due to confusing
semantics. To illustrate: 0.1 < 0.1 evaluates to true.
-?, --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 archive [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.
--ctrl-tarfile archive
Output the control tar-file contained in a Debian package.
--fsys-tarfile archive
Output 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 (since
dpkg 1.14.6).
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 (since dpkg 1.15.8). 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
(since dpkg 1.15.8.6). 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.
script-chrootless: Run maintainer scrips without chroot(2)ing
into instdir even if the package does not support this mode of
operation (since dpkg 1.18.5).
Warning: This can destroy your host system, use with extreme
care.
architecture: Process even packages with wrong or no
architecture.
bad-version: Process even packages with wrong versions (since
dpkg 1.16.1).
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
--record-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, purge, add-architecture and remove-architecture dpkg
actions (since dpkg 1.15.4; add-architecture and
remove-architecture actions since dpkg 1.17.19). 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 (since dpkg 1.15.8).
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.
The filters are applied when unpacking the binary packages, and
as such only have knowledge of the type of object currently
being filtered (e.g. a normal file or a directory) and have not
visibility of what objects will come next. Because these
filters have side effects (in contrast to find(1) filters),
excluding an exact pathname that happens to be a directory
object like /usr/share/doc will not have the desired result, and
only that pathname will be excluded (which could be
automatically reincluded if the code sees the need). Any
subsequent files contained within that directory will fail to
unpack.
Hint: make sure the globs are not expanded by your shell.
--verify-format format-name
Sets the output format for the --verify command (since dpkg
1.17.2).
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 each specific check
result, 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 md5sum verification failure (the file contents have changed)
is 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, to be run via "sh -c" (since
dpkg 1.16.0). 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 startup type command' for each dpkg
invocation where type is archives (with a command of unpack or
install) or packages (with a command of configure,
triggers-only, remove or purge); '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, configure,
trigproc, disappear, remove or 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 (since dpkg 1.14.17), but
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 (since dpkg 1.14.17).
EXIT STATUS
0 The requested action was successfully performed. Or a check or
assertion command returned true.
1 A check or assertion command returned false.
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.
ENVIRONMENT
External environment
PATH This variable is expected to be defined in the environment and
point to the system paths where several required programs are to
be found. If it's not set or the programs are not found, dpkg
will abort.
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 interactive
shell.
COLUMNS
Sets the number of columns dpkg should use when displaying
formatted text. Currently only used by --list.
DPKG_COLORS
Sets the color mode (since dpkg 1.18.5). The currently accepted
values are: auto, always and never (default).
Internal environment
DPKG_ROOT
Defined by dpkg on the maintainer script environment to indicate
which installation to act on (since dpkg 1.18.5). The value is
intended to be prepended to any path maintainer scripts operate
on. During normal operation, this variable is empty. When
installing packages into a different instdir, dpkg normally
invokes maintainer scripts using chroot(2) and leaves this
variable empty, but if --force-script-chrootless is specified
then the chroot(2) call is skipped and instdir is non-empty.
DPKG_SHELL_REASON
Defined by dpkg on the shell spawned on the conffile prompt to
examine the situation (since dpkg 1.15.6). Current valid value:
conffile-prompt.
DPKG_CONFFILE_OLD
Defined by dpkg on the shell spawned on the conffile prompt to
examine the situation (since dpkg 1.15.6). 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 (since dpkg 1.15.6). Contains the path to
the new conffile.
DPKG_HOOK_ACTION
Defined by dpkg on the shell spawned when executing a hook
action (since dpkg 1.15.4). Contains the current dpkg action.
DPKG_RUNNING_VERSION
Defined by dpkg on the maintainer script environment to the
version of the currently running dpkg instance (since dpkg
1.14.17).
DPKG_MAINTSCRIPT_PACKAGE
Defined by dpkg on the maintainer script environment to the
(non-arch-qualified) package name being handled (since dpkg
1.14.17).
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 (since dpkg 1.15.4).
DPKG_MAINTSCRIPT_NAME
Defined by dpkg on the maintainer script environment to the name
of the script running, one of preinst, postinst, prerm or postrm
(since dpkg 1.15.7).
DPKG_MAINTSCRIPT_DEBUG
Defined by dpkg on the maintainer script environment to a value
('0' or '1') noting whether debugging has been requested (with
the --debug option) for the maintainer scripts (since dpkg
1.18.4).
FILES
/etc/dpkg/dpkg.cfg.d/[0-9a-zA-Z_-]*
Configuration fragment files (since dpkg 1.15.4).
/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 (deb-control(5))
conffiles (deb-conffiles(5))
preinst
postinst
prerm
postrm
triggers (deb-triggers(5))
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:
apt-cache dumpavail | dpkg --merge-avail
or with dpkg 1.17.6 and earlier:
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.
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