Provided by: dpkg_1.22.6ubuntu6.1_amd64 bug

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 medium-level tool to install, build, remove and manage Debian packages.  The primary and more
       user-friendly front-end for dpkg as a CLI (command-line interface) is apt(8) and as a TUI (terminal user
       interface) is aptitude(8).  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  or  the postrm script and the data it needs to remove 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 kept on the same version,  that  is,  no  automatic  new  installs,
           upgrades or removals will be performed on them, unless these actions are requested explicitly, or are
           permitted to be done automatically with the --force-hold option.

       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).

       unknown
           The package selection is unknown.  A package that is also in a not-installed state, and  with  an  ok
           flag will be forgotten in the next database store.

   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.

           Will process triggers for Pre-Depends unless --no-triggers has been specified.

       --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 (which is part of the debconf project).

           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.

           Will process triggers unless --no-triggers has been specified.

       --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 and other data cleaned  up  by
           the  postrm  script,  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  there
           is  no  DEBIAN/conffiles control file nor DEBIAN/postrm script, this command is equivalent to calling
           --purge.  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.

           Will process triggers unless --no-triggers has been specified.

       -P, --purge package...|-a|--pending
           Purge  an  installed  or  already removed package.  This removes everything, including conffiles, and
           anything else cleaned up from postrm.  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.

           Will process triggers unless --no-triggers has been specified.

       -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.  This is
           only an integrity check and should not be considered as any kind of security verification.

           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.

           Note: This command makes use of both the available file and the package selections.

       --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.

           Note: This command makes use of both the available file and the package selections.

           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-help
           Give help about the --assert-feature options (since dpkg 1.21.0).

       --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).

           protected-field
               Supports the Protected field (since dpkg 1.20.1).

       --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.

           When used with --robot, the output will be the program version number in a dotted  numerical  format,
           with no newline.

       dpkg-deb actions
           See  dpkg-deb(1)  for more information about the following actions, and other actions and options not
           exposed by the dpkg front-end.

           -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, and other actions and options not
           exposed by the dpkg front-end.

           -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 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 for example 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:
             Allow automatic installs, upgrades or removals of packages even when marked to be on “hold”.  Note:
             When these actions are requested  explicitly,  the  “hold”  package  selection  state  always  gets
             ignored.

           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-protected:
             Remove,  even  if  the  package  is  considered  protected (since dpkg 1.20.1).  Protected packages
             contain mostly important system boot infrastructure or  are  used  for  custom  system-local  meta-
             packages.   Removing  them  might  cause  the  whole  system  to be unable to boot or lose required
             functionality to operate, so use with caution.

           remove-essential:
             Remove, even if the package is considered essential.  Essential packages contain mostly very  basic
             Unix  commands,  required  for  the packaging system, for the operation of the system in general or
             during boot (although the latter should be converted to protected packages instead).  Removing them
             might cause the whole system to stop working, so use with caution.

           depends:
             Turn all dependency problems into warnings.  This affects the Pre-Depends and Depends fields.

           depends-version:
             Don't care about versions when checking dependencies.  This affects  the  Pre-Depends  and  Depends
             fields.

           breaks:
             Install,  even  if  this  would break another package (since dpkg 1.14.6).  This affects the Breaks
             field.

           conflicts:
             Install, even if it conflicts with another package.  This is dangerous, for it will  usually  cause
             overwriting of some files.  This affects the Conflicts field.

           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 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.

           statoverride-add:
             Overwrite an existing stat override when adding it (since dpkg 1.19.5).

           statoverride-remove:
             Ignore a missing stat override when removing it (since dpkg 1.19.5).

           security-mac(*):
             Use platform-specific Mandatory Access Controls (MAC) based security when installing files into the
             filesystem (since dpkg 1.19.5).  On Linux systems the implementation uses SELinux.

           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 scripts 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).  This affects the Pre-Depends, Depends and Breaks fields.

       --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
           Set the administrative directory  to  directory.   This  directory  contains  many  files  that  give
           information  about  status of installed or uninstalled packages, etc.  Defaults to «/var/lib/dpkg» if
           DPKG_ADMINDIR has not been set.

       --instdir=dir
           Set the 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
           Set the root directory to  directory,  which  sets  the  installation  directory  to  «dir»  and  the
           administrative directory 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 and architecture of the package is already installed.

           Since  dpkg  1.21.10,  the architecture is also taken into account, which makes it possible to cross-
           grade packages or install additional co-installable instances with the same  version,  but  different
           architecture.

       --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 actions (since dpkg 1.15.4), and 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, in particular when there
           is a more specific re-inclusion, 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.  These lines have the following format:

            missing   [c] pathname [(error-message)]
            ??5?????? [c] pathname

           The  first  9 characters are used to report the checks result, either a literal missing when the file
           is not present or its metadata cannot be fetched, or one of the  following  special  characters  that
           report the result for each check:

           ‘?’ Implies the check could not be done (lack of support, file permissions, etc).

           ‘.’ Implies the check passed.

           ‘A-Za-z0-9’
               Implies  a  specific  check  failed.   The  following  positions  and alphanumeric characters are
               currently supported:

               1 ‘?’
                   These checks are currently not supported, will always be ‘?’.

               2 ‘M’
                   The file mode check failed (since dpkg 1.21.0).  Because pathname metadata is  currently  not
                   tracked,  this check can only be partially emulated via a very simple heuristic for pathnames
                   that have a known digest, which implies they should be regular files, where  the  check  will
                   fail  if  the  pathname  is  not a regular file on the filesystem.  This check will currently
                   never succeed as it does not have enough information available.

               3 ‘5’
                   The digest check failed, which means the  file  contents  have  changed.   This  is  only  an
                   integrity check and should not be considered as any kind of security verification.

               4-9 ‘?’
                   These checks are currently not supported, will always be ‘?’.

           The  line  is  followed  by a space and an attribute character.  The following attribute character is
           supported:

           ‘c’ The pathname is a conffile.

           Finally followed by another space and the pathname.

           In case the entry was of the missing type, and the file was not actually present on  the  filesystem,
           then the line is followed by a space and the error message enclosed within parenthesis.

       --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.

       --robot
           Use a machine-readable output format.  This provides an interface for programs that need to parse the
           output of some of the commands that do not otherwise  emit  a  machine-readable  output  format.   No
           localization will be used, and the output will be modified to make it easier to parse.

           The only currently supported command is --version.

       --no-pager
           Disables the use of any pager when showing information (since dpkg 1.19.2).

       --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.

       SHELL
           The program dpkg will execute when starting a new interactive shell, or when spawning a command via a
           shell.

       PAGER
       DPKG_PAGER
           The program dpkg will execute when running a pager, which will be  executed  with  «$SHELL  -c»,  for
           example  when  displaying  the conffile differences.  If SHELL is not set, «sh» will be used instead.
           The DPKG_PAGER overrides the PAGER environment variable (since dpkg 1.19.2).

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

       DPKG_DEBUG
           Sets  the  debug  mask  (since  dpkg  1.21.10) from an octal value.  The currently accepted flags are
           described in the --debug option.

       DPKG_FORCE
           Sets the force flags (since dpkg 1.19.5).  When this variable is present, no built-in force  defaults
           will be applied.  If the variable is present but empty, all force flags will be disabled.

       DPKG_ADMINDIR
           If  set  and  the  --admindir  or --root options have not been specified, it will be used as the dpkg
           administrative directory (since dpkg 1.20.0).

       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
       LESS
           Defined  by  dpkg  to  “-FRSXMQ”,  if not already set, when spawning a pager (since dpkg 1.19.2).  To
           change the default behavior, this variable can be preset to  some  other  value  including  an  empty
           string,  or  the  PAGER or DPKG_PAGER variables can be set to disable specific options with «-+», for
           example DPKG_PAGER="less -+F".

       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_FORCE
           Defined by dpkg on the subprocesses environment to all  the  currently  enabled  force  option  names
           separated by commas (since dpkg 1.19.5).

       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).

   Filesystem filenames
       During unpacking and configuration dpkg uses various filenames for backup  and  rollback  purposes.   The
       following is a simplified explanation of how these filenames get used during package installation.

       *.dpkg-new
           During  unpack,  dpkg  extracts  new  filesystem  objects into pathname.dpkg-new (except for existing
           directories or symlinks to directories which get  skipped),  once  that  is  done  and  after  having
           performed backups of the old objects, the objects get renamed to pathname.

       *.dpkg-tmp
           During  unpack,  dpkg  makes  backups  of  the  old  filesystem  objects into pathname.dpkg-tmp after
           extracting the new objects.  These backups are performed as either a rename for directories (but only
           if they switch file type), a new symlink copy for symlinks, or a hard link for any  other  filesystem
           object, except for conffiles which get no backups because they are processed at a later stage.

           In  case  of  needing  to  rollback,  these  backups get used to restore the previous contents of the
           objects.  These get removed automatically after the installation is complete.

       *.dpkg-old
           During configuration, when installing a new version, dpkg can make a backup of the previous  modified
           conffile into pathname.dpkg-old.

       *.dpkg-dist
           During  configuration,  when  keeping  the  old version, dpkg can make a backup of the new unmodified
           conffile into pathname.dpkg-dist.

SECURITY

       Any operation that needs write access to the database  or  the  filesystem  is  considered  a  privileged
       operation  that  might  allow  root escalation.  These operations must never be delegated to an untrusted
       user or be done on untrusted packages, as that might allow root access to the system.

       Some operations (such as package verification) might need root privileges to be able to access  files  on
       the  filesystem  that would otherwise be inaccessible due to restricted permissions, but should otherwise
       work normally and produce appropriate messages in those cases.

       Query operations should never require root, and delegating their execution to unprivileged users via some
       gain-root command can have security implications (such as privilege escalation), for example when a pager
       is automatically invoked by the tool.

       See also the SECURITY section of the dpkg-deb(1) and dpkg-split(1) manual pages.

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 vim neovim | less

       To search the listing of packages yourself:

        dpkg --print-avail | less

       To remove an installed neovim package:

        dpkg -r neovim

       To install a package, you first need to find it in an archive or media disc.  When using an archive based
       on  a  pool  structure,  knowing  the  archive  area  and  the name of the package is enough to infer the
       pathname:

        dpkg -i /media/bdrom/pool/main/v/vim/vim_9.0.2018-1_amd64.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#set-selections> for
       more details), for example:

        apt-cache dumpavail | dpkg --merge-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
       debsig-verify.

SEE ALSO

       aptitude(8), apt(8), 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.

1.22.6                                             2024-07-17                                            dpkg(1)