apt-get(8) - Linux man page

Name

Synopsis

apt-get [ -hvs ] [ -o=config string ] [ -c=file ] { update | upgrade | dselect-upgrade | install pkg ... | remove pkg ... | source pkg ... | build-dep pkg ... | check | clean | autoclean }

Description

apt-get is the command-line tool for handling packages, and may be considered the user's "back-end" to other tools using the APT library. Several "front-end" interfaces exist, such as dselect(8), aptitude, synaptic, gnome-apt and wajig.

Unless the -h, or --help option is given, one of the commands below must be present.

update

update is used to resynchronize the package index files from their sources. The indexes of available packages are fetched from the location(s) specified in /etc/apt/sources.list. For example, when using a Debian archive, this command retrieves and scans the Packages.gz files, so that information about new and updated packages is available. An update should always be performed before an upgrade or dist-upgrade. Please be aware that the overall progress meter will be incorrect as the size of the package files cannot be known in advance.

upgrade

upgrade is used to install the newest versions of all packages currently installed on the system from the sources enumerated in /etc/apt/sources.list. Packages currently installed with new versions available are retrieved and upgraded; under no circumstances are currently installed packages removed, or packages not already installed retrieved and installed. New versions of currently installed packages that cannot be upgraded without changing the install status of another package will be left at their current version. An update must be performed first so that apt-get knows that new versions of packages are available.

dselect-upgrade

dselect-upgrade is used in conjunction with the traditional Debian packaging front-end, dselect(8). dselect-upgrade follows the changes made by dselect(8) to the Status field of available packages, and performs the actions necessary to realize that state (for instance, the removal of old and the installation of new packages).

dist-upgrade

dist-upgrade, in addition to performing the function of upgrade, also intelligently handles changing dependencies with new versions of packages; apt-get has a "smart" conflict resolution system, and it will attempt to upgrade the most important packages at the expense of less important ones if necessary. The /etc/apt/sources.list file contains a list of locations from which to retrieve desired package files. See also apt_preferences(5) for a mechanism for overriding the general settings for individual packages.

install

install is followed by one or more packages desired for installation. Each package is a package name, not a fully qualified filename (for instance, in a Debian GNU/Linux system, libc6 would be the argument provided, not libc6_1.9.6-2.deb). All packages required by the package(s) specified for installation will also be retrieved and installed. The /etc/apt/sources.list file is used to locate the desired packages. If a hyphen is appended to the package name (with no intervening space), the identified package will be removed if it is installed. Similarly a plus sign can be used to designate a package to install. These latter features may be used to override decisions made by apt-get's conflict resolution system.

A specific version of a package can be selected for installation by following the package name with an equals and the version of the package to select. This will cause that version to be located and selected for install. Alternatively a specific distribution can be selected by following the package name with a slash and the version of the distribution or the Archive name (stable, testing, unstable).

Both of the version selection mechanisms can downgrade packages and must be used with care.

Finally, the apt_preferences(5) mechanism allows you to create an alternative installation policy for individual packages.

If no package matches the given expression and the expression contains one of '.', '?' or '*' then it is assumed to be a POSIX regular expression, and it is applied to all package names in the database. Any matches are then installed (or removed). Note that matching is done by substring so 'lo.*' matches 'how-lo' and 'lowest'. If this is undesired, anchor the regular expression with a '^' or '$' character, or create a more specific regular expression.

remove

remove is identical to install except that packages are removed instead of installed. If a plus sign is appended to the package name (with no intervening space), the identified package will be installed instead of removed.

source

source causes apt-get to fetch source packages. APT will examine the available packages to decide which source package to fetch. It will then find and download into the current directory the newest available version of that source package. Source packages are tracked separately from binary packages via deb-src type lines in the sources.list(5) file. This probably will mean that you will not get the same source as the package you have installed or as you could install. If the --compile options is specified then the package will be compiled to a binary .deb using dpkg-buildpackage, if --download-only is specified then the source package will not be unpacked.

A specific source version can be retrieved by postfixing the source name with an equals and then the version to fetch, similar to the mechanism used for the package files. This enables exact matching of the source package name and version, implicitly enabling the APT::Get::Only-Source option.

Note that source packages are not