The Debian GNU/Linux FAQ
Chapter 7 The Debian Package Management Tools

7.1 What programs does Debian provide for managing its packages?

7.1.1 dpkg

This is the main package management program. dpkg can be invoked with many options. Some common uses are:

• Find out all the options: dpkg --help.
• Print out the control file (and other information) for a specified package: dpkg --info foo_VVV-RRR.deb
• Install a package (including unpacking and configuring) onto the file system of the hard disk: dpkg --install foo_VVV-RRR.deb.
• Unpack (but do not configure) a Debian archive into the file system of the hard disk: dpkg --unpack foo_VVV-RRR.deb. Note that this operation does not necessarily leave the package in a usable state; some files may need further customization to run properly. This command removes any already-installed version of the program and runs the preinst (see What is a Debian preinst, postinst, prerm, and postrm script?, Section 6.6) script associated with the package.
• Configure a package that already has been unpacked: dpkg --configure foo. Among other things, this action runs the postinst (see What is a Debian preinst, postinst, prerm, and postrm script?, Section 6.6) script associated with the package. It also updates the files listed in the conffiles for this package. Notice that the 'configure' operation takes as its argument a package name (e.g., foo), not the name of a Debian archive file (e.g., foo_VVV-RRR.deb).
• Extract a single file named "blurf" (or a group of files named "blurf*" from a Debian archive: dpkg --fsys-tarfile foo_VVV-RRR.deb | tar -xf - blurf*
• Remove a package (but not its configuration files): dpkg --remove foo.
• Remove a package (including its configuration files): dpkg --purge foo.
• List the installation status of packages containing the string (or regular expression) "foo*": dpkg --list 'foo*'.

7.1.2 dselect

This program is a menu-driven interface to the Debian package management system. It is particularly useful for first-time installations and large-scale upgrades.

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 se