Provided by: dselect_1.21.1ubuntu2_amd64 bug

NAME

       dselect - Debian package management frontend

SYNOPSIS

       dselect [option...] [command...]

DESCRIPTION

       dselect is one of the primary user interfaces for managing packages on a Debian system. At
       the dselect main menu, the system administrator can:

       ·   Update the list of available package versions,

       ·   View the status of installed and available packages,

       ·   Alter package selections and manage dependencies,

       ·   Install new packages or upgrade to newer versions.

       dselect operates as a front-end to dpkg(1), the low-level Debian package handling tool. It
       features a full-screen package selections manager with package depends and conflicts
       resolver. When run with administrator privileges, packages can be installed, upgraded and
       removed. Various access methods can be configured to retrieve available package version
       information and installable packages from package repositories.  Depending on the used
       access method, these repositories can be public archive servers on the internet, local
       archive servers or CD-ROMs.  The recommended access method is apt, which is provided by
       the package apt(8).

       Normally dselect is invoked without parameters. An interactive menu is presented, offering
       the user a list of commands. If a command is given as argument, then that command is
       started immediately. Several command line parameters are still available to modify the
       running behaviour of dselect or show additional information about the program.

OPTIONS

       All options can be specified both on the command line and in the dselect configuration
       file /etc/dpkg/dselect.cfg or the files on the configuration directory
       /etc/dpkg/dselect.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 ‘#’).

       --admindir directory
           Changes the directory where the dpkg ‘status’, ‘available’ and similar files are
           located.  This defaults to /var/lib/dpkg and normally there shouldn't be any need to
           change it.

       --root directory
           Set the root directory to directory, which sets the administrative directory to
           «directory/var/lib/dpkg» (since dpkg 1.21.0).

       -Dfile, --debug file
           Turn on debugging. Debugging information is sent to file.

       --expert
           Turns on expert mode, i.e. doesn't display possibly annoying help messages.

       --color screenpart:[foreground],[background][:attr[+attr]...]
       --colour screenpart:[foreground],[background][:attr[+attr]...]
           Configures screen colors. This works only if your display supports colors.  This
           option may be used multiple times (and is best used in dselect.cfg). Each use changes
           the color (and optionally, other attributes) of one part of the screen.  The parts of
           the screen (from top to bottom) are:

           title
               The screen title.

           listhead
               The header line above the list of packages.

           list
               The scrolling list of packages (and also some help text).

           listsel
               The selected item in the list.

           pkgstate
               In the list of packages, the text indicating the current state of each package.

           pkgstatesel
               In the list of packages, the text indicating the current state of the currently
               selected package.

           infohead
               The header line that displays the state of the currently selected package.

           infodesc
               The package's short description.

           info
               Used to display package info such as the package's description.

           infofoot
               The last line of the screen when selecting packages.

           query
               Used to display query lines

           helpscreen
               Color of help screens.

           After the part of the screen comes a colon and the color specification. You can
           specify either the foreground color, the background color, or both, overriding the
           compiled-in colors. Use standard curses color names.

           Optionally, after the color specification is another colon, and an attribute
           specification. This is a list of one or more attributes, separated by plus (‘+’)
           characters.  Available attributes include (not all of these will work on all
           terminals): normal, standout, underline, reverse, blink, bright, dim, bold

       -?, --help
           Print a brief help text and exit successfully.

       --version
           Print version information and exit successfully.

COMMANDS

       When dselect is started it can perform the following commands, either directly if it was
       specified on the command line or by prompting the user with a menu of available commands
       if running interactively:

   access
       Choose and configure an access method to access package repositories.

       By default, dselect provides several methods such as multi_cd, mounted or ftp, but other
       packages may provide additional methods, eg. the apt access method provided by the apt(8)
       package.

       The use of the apt access method is strongly recommended.

   update
       Refresh the available packages database.

       Retrieves a list of available package versions from the package repository, configured for
       the current access method, and update the dpkg database. The package lists are commonly
       provided by the repository as files named Packages or Packages.gz.  These files can be
       generated by repository maintainers, using the program dpkg-scanpackages(1).

       Details of the update command depend on the access method's implementation.  Normally the
       process is straightforward and requires no user interaction.

   select
       View or manage package selections and dependencies.

       This is the main function of dselect. In the select screen, the user can review a list of
       all available and installed packages. When run with administrator privileges, it is also
       possible to interactively change packages selection state. dselect tracks the implications
       of these changes to other depending or conflicting packages.

       When a conflict or failed depends is detected, a dependency resolution subscreen is
       prompted to the user. In this screen, a list of conflicting or depending packages is
       shown, and for each package listed, the reason for its listing is shown. The user may
       apply the suggestions proposed by dselect, override them, or back out all the changes,
       including the ones that created the unresolved depends or conflicts.

       The use of the interactive package selections management screen is explained in more
       detail below.

   install
       Installs selected packages.

       The configured access method will fetch installable or upgradable packages from the
       relevant repositories and install these using dpkg.  Depending on the implementation of
       the access method, all packages can be prefetched before installation, or fetched when
       needed.  Some access methods may also remove packages that were marked for removal.

       If an error occurred during install, it is usually advisable to run install again. In most
       cases, the problems will disappear or be solved.  If problems persist or the installation
       performed was incorrect, please investigate into the causes and circumstances, and file a
       bug in the Debian bug tracking system. Instructions on how to do this can be found at
       <https://bugs.debian.org/> or by reading the documentation for bug(1) or reportbug(1), if
       these are installed.

       Details of the install command depend on the access method's implementation.  The user's
       attention and input may be required during installation, configuration or removal of
       packages. This depends on the maintainer scripts in the package. Some packages make use of
       the debconf(1) library, allowing for more flexible or even automated installation setups.

   config
       Configures any previously installed, but not fully configured packages.

   remove
       Removes or purges installed packages, that are marked for removal.

   quit
       Quit dselect.

       Exits the program with zero (successful) error code.

PACKAGE SELECTIONS MANAGEMENT

   Introduction
       dselect directly exposes the administrator to some of the complexities involved with
       managing large sets of packages with many interdependencies. For a user who is unfamiliar
       with the concepts and the ways of the Debian package management system, it can be quite
       overwhelming. Although dselect is aimed at easing package management and administration,
       it is only instrumental in doing so and cannot be assumed to be a sufficient substitute
       for administrator skill and understanding. The user is required to be familiar with the
       concepts underlying the Debian packaging system.  In case of doubt, consult the dpkg(1)
       manpage and the distribution policy.

       Unless dselect is run in expert or immediate mode, a help screen is first displayed when
       choosing this command from the menu. The user is strongly advised to study all of the
       information presented in the online help screens, when one pops up.  The online help
       screens can at any time be invoked with the ‘?’ key.

   Screen layout
       The select screen is by default split in a top and a bottom half.  The top half shows a
       list of packages. A cursor bar can select an individual package, or a group of packages,
       if applicable, by selecting the group header. The bottom half of the screen shows some
       details about the package currently selected in the top half of the screen.  The type of
       detail that is displayed can be varied.

       Pressing the ‘I’ key toggles a full-screen display of the packages list, an enlarged view
       of the package details, or the equally split screen.

   Package details view
       The package details view by default shows the extended package description for the package
       that is currently selected in the packages status list.  The type of detail can be toggled
       by pressing the ‘i’ key.  This alternates between:

       ·   the extended description

       ·   the control information for the installed version

       ·   the control information for the available version

       In a dependency resolution screen, there is also the possibility of viewing the specific
       unresolved depends or conflicts related to the package and causing it to be listed.

   Packages status list
       The main select screen displays a list of all packages known to the Debian package
       management system. This includes packages installed on the system and packages known from
       the available packages database.

       For every package, the list shows the package's status, priority, section, installed and
       available architecture, installed and available versions, the package name and its short
       description, all in one line.  By pressing the ‘A’ key, the display of the installed and
       available architecture can be toggled between on an off.  By pressing the ‘V’ key, the
       display of the installed and available version can be toggled between on an off.  By
       pressing the ‘v’ key, the package status display is toggled between verbose and shorthand.
       Shorthand display is the default.

       The shorthand status indication consists of four parts: an error flag, which should
       normally be clear, the current status, the last selection state and the current selection
       state.  The first two relate to the actual state of the package, the second pair are about
       the selections set by the user.

       These are the meanings of the shorthand package status indicator codes:

           Error flag:

           empty   no error
           R       serious error, needs reinstallation;

           Installed state:

           empty   not installed;
           *       fully installed and configured;
           -       not installed but some config files may remain;
           U       unpacked but not yet configured;
           C       half-configured (an error happened);
           I       half-installed (an error happened).

           Current and requested selections:

           *       marked for installation or upgrade;
           -       marked for removal, configuration files remain;
           =       on hold: package will not be processed at all;
           _       marked for purge, also remove configuration;
           n       package is new and has yet to be marked.

   Cursor and screen movement
       The package selection list and the dependency conflict resolution screens can be navigated
       using motion commands mapped to the following keys:

           p, Up, k           move cursor bar up
           n, Down, j         move cursor bar down
           P, Pgup, Backspace scroll list 1 page up
           N, Pgdn, Space     scroll list 1 page down
           ^p                 scroll list 1 line up
           ^n                 scroll list 1 line down
           t, Home            jump to top of list
           e, End             jump to end of list
           u                  scroll info 1 page up
           d                  scroll info 1 page down
           ^u                 scroll info 1 line up
           ^d                 scroll info 1 line down
           B, Left-arrow      pan display 1/3 screen left
           F, Right-arrow     pan display 1/3 screen right
           ^b                 pan display 1 character left
           ^f                 pan display 1 character right

   Searching and sorting
       The list of packages can be searched by package name. This is done by pressing ‘/’, and
       typing a simple search string. The string is interpreted as a regex(7) regular expression.
       If you add ‘/d’ to the search expression, dselect will also search in descriptions.  If
       you add ‘/i’ the search will be case insensitive.  You may combine these two suffixes like
       this: ‘/id’.  Repeated searching is accomplished by repeatedly pressing the ‘n’ or ‘\’
       keys, until the wanted package is found.  If the search reaches the bottom of the list, it
       wraps to the top and continues searching from there.

       The list sort order can be varied by pressing the ‘o’ and ‘O’ keys repeatedly.  The
       following nine sort orderings can be selected:

           alphabet
           priority+section
           section+priority
           available
           available+priority
           available+section
           status
           status+priority
           status+section

       Where not listed above explicitly, alphabetic order is used as the final subordering sort
       key.

   Altering selections
       The requested selection state of individual packages may be altered with the following
       commands:

           +, Insert    install or upgrade
           =, H         hold in present state and version
           :, G         unhold: upgrade or leave uninstalled
           -, Delete    remove, but leave configuration
           _            remove & purge configuration

       When the change request results in one or more unsatisfied depends or conflicts, dselect
       prompts the user with a dependency resolution screen. This will be further explained
       below.

       It is also possible to apply these commands to groups of package selections, by pointing
       the cursor bar onto a group header. The exact grouping of packages is dependent on the
       current list ordering settings.

       Proper care should be taken when altering large groups of selections, because this can
       instantaneously create large numbers of unresolved depends or conflicts, all of which will
       be listed in one dependency resolution screen, making them very hard to handle. In
       practice, only hold and unhold operations are useful when applied to groups.

   Resolving depends and conflicts
       When the change request results in one or more unsatisfied depends or conflicts, dselect
       prompts the user with a dependency resolution screen. First however, an informative help
       screen is displayed.

       The top half of this screen lists all the packages that will have unresolved depends or
       conflicts, as a result of the requested change, and all the packages whose installation
       can resolve any of these depends or whose removal can resolve any of the conflicts.  The
       bottom half defaults to show the depends or conflicts that cause the currently selected
       package to be listed.

       When the sublist of packages is displayed initially, dselect may have already set the
       requested selection status of some of the listed packages, in order to resolve the depends
       or conflicts that caused the dependency resolution screen to be displayed. Usually, it is
       best to follow up the suggestions made by dselect.

       The listed packages' selection state may be reverted to the original settings, as they
       were before the unresolved depends or conflicts were created, by pressing the ‘R’ key.  By
       pressing the ‘D’ key, the automatic suggestions are reset, but the change that caused the
       dependency resolution screen to be prompted is kept as requested.  Finally, by pressing
       ‘U’, the selections are again set to the automatic suggestion values.

   Establishing the requested selections
       By pressing enter, the currently displayed set of selections is accepted. If dselect
       detects no unresolved depends as a result of the requested selections, the new selections
       will be set.  However, if there are any unresolved depends, dselect will again prompt the
       user with a dependency resolution screen.

       To alter a set of selections that creates unresolved depends or conflicts and forcing
       dselect to accept it, press the ‘Q’ key. This sets the selections as specified by the
       user, unconditionally. Generally, don't do this unless you've read the fine print.

       The opposite effect, to back out any selections change requests and go back to the
       previous list of selections, is attained by pressing the ‘X’ or escape keys. By repeatedly
       pressing these keys, any possibly detrimental changes to the requested package selections
       can be backed out completely to the last established settings.

       If you mistakenly establish some settings and wish to revert all the selections to what is
       currently installed on the system, press the ‘C’ key.  This is somewhat similar to using
       the unhold command on all packages, but provides a more obvious panic button in cases
       where the user pressed enter by accident.

EXIT STATUS

       0   The requested command was successfully performed.

       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

       DPKG_ROOT
           If set and the --root option has not been specified, it will be used as the filesystem
           root directory (since dpkg 1.21.0).

       DPKG_ADMINDIR
           If set and the --admindir option has not been specified, it will be used as the dpkg
           database directory (since dpkg 1.21.0).

       HOME
           If set, dselect will use it as the directory from which to read the user specific
           configuration file.

BUGS

       The dselect package selection interface is confusing to some new users.  Reportedly, it
       even makes seasoned kernel developers cry.

       The documentation is lacking.

       There is no help option in the main menu.

       The visible list of available packages cannot be reduced.

       The built in access methods can no longer stand up to current quality standards. Use the
       access method provided by apt(8), it is not only not broken, it is also much more flexible
       than the built in access methods.

SEE ALSO

       dpkg(1), apt(8), sources.list(5), deb(5).