Provided by: dselect_1.19.7ubuntu3.2_amd64 
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 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 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.
-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.
--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.
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 cdrom, multi_cd, nfs, multi_nfs, harddisk, mounted,
multi_mount 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 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) 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 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 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.
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
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).
1.19.7 2022-05-25 dselect(1)