Provided by: dpkg_1.19.0.5ubuntu2.4_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 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).
--validate-thing string
Validate that the thing string has a correct syntax (since dpkg 1.18.16). Returns
0 if the string is valid, 1 if the string is invalid but might be accepted in lax
contexts, and 2 if the string is invalid. The current list of validatable things
is:
pkgname
Validates the given package name (since dpkg 1.18.16).
trigname
Validates the given trigger name (since dpkg 1.18.16).
archname
Validates the given architecture name (since dpkg 1.18.16).
version
Validates the given version (since dpkg 1.18.16).
--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-oring 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: 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-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.
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
(default), always and never.
DPKG_FRONTEND_LOCKED
Set by a package manager frontend to notify dpkg that it should not acquire the
frontend lock (since dpkg 1.19.1).
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_ADMINDIR
Defined by dpkg on the maintainer script environment to indicate the dpkg
administrative directory to use (since dpkg 1.16.0). This variable is always set
to the current --admindir value.
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 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 format and contents of a binary package are described in deb(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.