7.1.4 dselect

This program is a menu-driven interface to the Debian package management system. It is particularly useful for first-time installations. Some users might feel more comfortable using aptitude which is also recommended over dselect for large-scale upgrades. For more information on aptitude please see aptitude, Section 7.1.3.

dselect can:

• guide the user as he/she chooses among packages to install or remove, ensuring that no packages are installed that conflict with one another, and that all packages required to make each package work properly are installed;

• warn the user about inconsistencies or incompatibilities in their selections;

• determine the order in which the packages must be installed;

• automatically perform the installation or removal; and

• guide the user through whatever configuration process are required for each package.

dselect begins by presenting the user with a menu of 7 items, each of which is a specific action. The user can select one of the actions by using the arrow keys to move the highlighter bar, then pressing the <enter> key to select the highlighted action.

What the user sees next depends on the action he selected. If he selects any option but Access or Select, then dselect will simply proceed to execute the specified action: e.g., if the user selected the action Remove, then dselect would proceed to remove all of the files selected for removal when the user last chose the Select action.

Both the Access menu item and the Select menu item lead to additional menus. In both cases, the menus are presented as split screens; the top screen gives a scrollable list of choices, while the bottom screen gives a brief explanation ("info") for each choice.

Extensive on-line help is available, use the '?' key to get to a help screen at any time.

The order in which the actions are presented in the first dselect menu represents the order in which a user would normally choose dselect to install packages. However, a user can pick any of the main menu choices as often as needed (including not at all, depending on what one wants to do).

• Begin by choosing an Access Method. This is the method by which the user plans on accessing Debian packages; e.g., some users have Debian packages available on CD-ROM, while others plan to fetch them using anonymous FTP. The selected "Access Method" is stored after dselect exits, so if it does not change, then this option need not be invoked again.

• Then Update the list of available packages. To do this, dselect reads the file "Packages.gz" which should be included in the top level of the directory where the Debian packages to be installed are stored. (But if it is not there, dselect will offer to make it for you.)

• Select specific packages for installation on his system. After choosing this menu item, the user is first presented with a full screen of help (unless the `--expert' command line option was used). Once the user exits the Help screen, he sees the split-screen menu for choosing packages to install (or remove).

  The top part of the screen is a relatively narrow window into the list of Debian's 15400 packages; the bottom part of the screen contains description of the package or group of packages which are highlighted above.

  One can specify which packages should be operated on by highlighting a package name or the label for a group of packages. After that, you can select packages:

  to be installed:

  This is accomplished by pressing the `+' key.

  to be deleted:

  Packages can be deleted two ways:

  • removed: this removes most of the files associated with the package, but preserves the files listed as configuration files (see What is a Debian conffile?, Section 6.5) and package configuration information. This is done by pressing the `-' key.

  • purged: this removes every file that is part of the package. This is done by pressing the `_' key.

  Note that it's not possible to remove "All Packages". If you try that, your system will instead be reduced to the initial installed base packages.

  to be put "on hold"

  This is done by pressing `=', and it effectively tells dselect not to upgrade a package even if the version currently installed on your system is not as recent as the version that is available in the Debian repository you are using (this was specified when you set the Access Method, and acquired when you used Update).

  Just like you can put a package on hold, you can reverse such setting by pressing `:'. That tells dselect that the package(s) may be upgraded if a newer version is available. This is the default setting.

  You can select a different order in which the packages are presented, by using the `o' key to cycle between various options for sorting the packages. The default order is to present packages by Priority; within each priority, packages are presented in order of the directory (a.k.a. section) of the archive in which they are stored. Given this sort order, some packages in section A (say) may be presented first, followed by some packages in section B, followed by more packages (of lower priority) in section A.

  You can also expand meanings of the labels at the top of the screen, by using the `v' (verbose) key. This action pushes much of the text that formerly fit onto the display off to the right. To see it, press the right arrow; to scroll back to the left, press the left arrow.

  If you select a package for installation or removal, e.g., foo.deb, and that package depends on (or recommends) another package, e.g., blurf.deb, then dselect will place the you in a sub-screen of the main selection screen. There you can choose among the related packages, accepting the suggested actions (to install or not), or rejecting them. To do the latter, press Shift-D; to return to the former, press Shift-U. In any case, you can save your selections and return to the main selection screen by pressing Shift-Q.

• Users returning to the main menu can then select the "Install" menu item to unpack and configure the selected packages. Alternatively, users wishing to remove files can choose the "Remove" menu item. At any point, users can choose "Quit" to exit dselect; users' selections are preserved by dselect.