trusty (1) dselect.1.gz

Provided by: dselect_1.17.5ubuntu5.8_amd64 bug

NAME

       dselect - Debian package management frontend

SYNOPSIS

       dselect [option...] [action]

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 cdroms.  The recommended access method is apt, which is provided
       by the package apt.

       Normally dselect is invoked without parameters. An interactive menu is presented,  offering  the  user  a
       list  of  actions.  If  an  action is given as argument, then that action 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.

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

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

       --colour|--color 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.

ACTIONS

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

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

       By  default, dselect provides several methods such as cdrom, multi_cd, nfs, multi_nfs, harddisk, mounted,
       multi_mount, floppy or ftp, but other packages may provide additional methods, eg. the apt access  method
       provided by the apt 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 action 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 http://bugs.debian.org/ or by reading the documentation
       for bug(1) or reportbug(1), if these are installed.

       Details of the install action 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) errorcode.

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 can not 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 Debian Policy manual, contained in the debian-policy package.

       Unless  dselect  is  run in expert or immediate mode, a help screen is first displayed when choosing this
       action 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
       versions,  the  package  name  and  its  short description, all in one line. 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          available           status
        priority+section  available+priority  status+priority
        section+priority  available+section   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.

ENVIRONMENT

       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, it is not only not broken, it is also much  more  flexible  than  the  built  in  access
       methods.

SEE ALSO

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