APT-GET(8)							APT							APT-GET(8)



NAME
       apt-get - APT package handling utility -- command-line interface

SYNOPSIS
       apt-get [-asqdyfmubV] [-o=config_string] [-c=config_file] [-t=target_release] [-a=architecture] {update | upgrade |
	       dselect-upgrade | dist-upgrade | install pkg [{=pkg_version_number | /target_release}]...  | remove pkg...  |
	       purge pkg...  | source pkg [{=pkg_version_number | /target_release}]...	|
	       build-dep pkg [{=pkg_version_number | /target_release}]...  |
	       download pkg [{=pkg_version_number | /target_release}]...  | check | clean | autoclean | autoremove |
	       {-v | --version} | {-h | --help}}

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(1), aptitude(8), synaptic(8) and wajig(1).

       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.

       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 dist-upgrade command may therefore remove
	   some packages. 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.

       dselect-upgrade
	   dselect-upgrade is used in conjunction with the traditional Debian packaging front-end, dselect(1).	dselect-upgrade
	   follows the changes made by dselect(1) 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).

       install
	   install is followed by one or more packages desired for installation or upgrading. Each package is a package name, not
	   a fully qualified filename (for instance, in a Debian system, apt-utils would be the argument provided, not
	   apt-utils_0.9.7.5ubuntu5.1_amd64.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.

	   This is also the target to use if you want to upgrade one or more already-installed packages without upgrading every
	   package you have on your system. Unlike the "upgrade" target, which installs the newest version of all currently
	   installed packages, "install" will install the newest version of only the package(s) specified. Simply provide the name
	   of the package(s) you wish to upgrade, and if a newer version is available, it (and its dependencies, as described
	   above) will be downloaded and installed.

	   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. Note that removing a package
	   leaves its configuration files on the system. If a plus sign is appended to the package name (with no intervening
	   space), the identified package will be installed instead of removed.

       purge
	   purge is identical to remove except that packages are removed and purged (any configuration files are deleted too).

       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
	   while respecting the default release, set with the option APT::Default-Release, the -t option or per package with the
	   pkg/release syntax, if possible.

	   Source packages are tracked separately from binary packages via deb-src lines in the sources.list(5) file. This means
	   that you will need to add such a line for each repository you want to get sources from; otherwise you will probably get
	   either the wrong (too old/too new) source versions or none at all.

	   If the --compile option is specified then the package will be compiled to a binary .deb using dpkg-buildpackage for the
	   architecture as defined by the --host-architecture option. 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 installed and tracked in the dpkg database like binary packages; they are simply
	   downloaded to the current directory, like source tarballs.

       build-dep
	   build-dep causes apt-get to install/remove packages in an attempt to satisfy the build dependencies for a source
	   package. By default the dependencies are satisfied to build the package natively. If desired a host-architecture can be
	   specified with the --host-architecture option instead.

       check
	   check is a diagnostic tool; it updates the package cache and checks for broken dependencies.

       download
	   download will download the given binary package into the current directory.

       clean
	   clean clears out the local repository of retrieved package files. It removes everything but the lock file from
	   /var/cache/apt/archives/ and /var/cache/apt/archives/partial/. When APT is used as a dselect(1) method, clean is run
	   automatically. Those who do not use dselect will likely want to run apt-get clean from time to time to free up disk
	   space.

       autoclean
	   Like clean, autoclean clears out the local repository of retrieved package files. The difference is that it only
	   removes package files that can no longer be downloaded, and are largely useless. This allows a cache to be maintained
	   over a long period without it growing out of control. The configuration option APT::Clean-Installed will prevent
	   installed packages from being erased if it is set to off.

       autoremove
	   autoremove is used to remove packages that were automatically installed to satisfy dependencies for other packages and
	   are now no longer needed.

       changelog
	   changelog downloads a package changelog and displays it through sensible-pager. The server name and base directory is
	   defined in the APT::Changelogs::Server variable (e.g.  packages.debian.org/changelogs[1] for Debian or
	   changelogs.ubuntu.com/changelogs[2] for Ubuntu). By default it displays the changelog for the version that is
	   installed. However, you can specify the same options as for the install command.

OPTIONS
       All command line options may be set using the configuration file, the descriptions indicate the configuration option to
       set. For boolean options you can override the config file by using something like -f-,--no-f, -f=no or several other
       variations.

       --no-install-recommends
	   Do not consider recommended packages as a dependency for installing. Configuration Item: APT::Install-Recommends.

       --install-suggests
	   Consider suggested packages as a dependency for installing. Configuration Item: APT::Install-Suggests.

       -d, --download-only
	   Download only; package files are only retrieved, not unpacked or installed. Configuration Item:
	   APT::Get::Download-Only.

       -f, --fix-broken
	   Fix; attempt to correct a system with broken dependencies in place. This option, when used with install/remove, can
	   omit any packages to permit APT to deduce a likely solution. If packages are specified, these have to completely
	   correct the problem. The option is sometimes necessary when running APT for the first time; APT itself does not allow
	   broken package dependencies to exist on a system. It is possible that a system's dependency structure can be so corrupt
	   as to require manual intervention (which usually means using dselect(1) or dpkg --remove to eliminate some of the
	   offending packages). Use of this option together with -m may produce an error in some situations. Configuration Item:
	   APT::Get::Fix-Broken.

       -m, --ignore-missing, --fix-missing
	   Ignore missing packages; if packages cannot be retrieved or fail the integrity check after retrieval (corrupted package
	   files), hold back those packages and handle the result. Use of this option together with -f may produce an error in
	   some situations. If a package is selected for installation (particularly if it is mentioned on the command line) and it
	   could not be downloaded then it will be silently held back. Configuration Item: APT::Get::Fix-Missing.

       --no-download
	   Disables downloading of packages. This is best used with --ignore-missing to force APT to use only the .debs it has
	   already downloaded. Configuration Item: APT::Get::Download.

       -q, --quiet
	   Quiet; produces output suitable for logging, omitting progress indicators. More q's will produce more quiet up to a
	   maximum of 2. You can also use -q=# to set the quiet level, overriding the configuration file. Note that quiet level 2
	   implies -y; you should never use -qq without a no-action modifier such as -d, --print-uris or -s as APT may decide to
	   do something you did not expect. Configuration Item: quiet.

       -s, --simulate, --just-print, --dry-run, --recon, --no-act
	   No action; perform a simulation of events that would occur but do not actually change the system. Configuration Item:
	   APT::Get::Simulate.

	   Simulated runs performed as a user will automatically deactivate locking (Debug::NoLocking), and if the option
	   APT::Get::Show-User-Simulation-Note is set (as it is by default) a notice will also be displayed indicating that this
	   is only a simulation. Runs performed as root do not trigger either NoLocking or the notice - superusers should know
	   what they are doing without further warnings from apt-get.

	   Simulated runs print out a series of lines, each representing a dpkg operation: configure (Conf), remove (Remv) or
	   unpack (Inst). Square brackets indicate broken packages, and empty square brackets indicate breaks that are of no
	   consequence (rare).

       -y, --yes, --assume-yes
	   Automatic yes to prompts; assume "yes" as answer to all prompts and run non-interactively. If an undesirable situation,
	   such as changing a held package, trying to install a unauthenticated package or removing an essential package occurs
	   then apt-get will abort. Configuration Item: APT::Get::Assume-Yes.

       --assume-no
	   Automatic "no" to all prompts. Configuration Item: APT::Get::Assume-No.

       -u, --show-upgraded
	   Show upgraded packages; print out a list of all packages that are to be upgraded. Configuration Item:
	   APT::Get::Show-Upgraded.

       -V, --verbose-versions
	   Show full versions for upgraded and installed packages. Configuration Item: APT::Get::Show-Versions.

       -a, --host-architecture
	   This option controls the architecture packages are built for by apt-get source --compile and how
	   cross-builddependencies are satisfied. By default is it not set which means that the host architecture is the same as
	   the build architecture (which is defined by APT::Architecture). Configuration Item: APT::Get::Host-Architecture

       -b, --compile, --build
	   Compile source packages after downloading them. Configuration Item: APT::Get::Compile.

       --ignore-hold
	   Ignore package holds; this causes apt-get to ignore a hold placed on a package. This may be useful in conjunction with
	   dist-upgrade to override a large number of undesired holds. Configuration Item: APT::Ignore-Hold.

       --no-upgrade
	   Do not upgrade packages; when used in conjunction with install, no-upgrade will prevent packages on the command line
	   from being upgraded if they are already installed. Configuration Item: APT::Get::Upgrade.

       --only-upgrade
	   Do not install new packages; when used in conjunction with install, only-upgrade will install upgrades for already
	   installed packages only and ignore requests to install new packages. Configuration Item: APT::Get::Only-Upgrade.

       --force-yes
	   Force yes; this is a dangerous option that will cause apt to continue without prompting if it is doing something
	   potentially harmful. It should not be used except in very special situations. Using force-yes can potentially destroy
	   your system! Configuration Item: APT::Get::force-yes.

       --print-uris
	   Instead of fetching the files to install their URIs are printed. Each URI will have the path, the destination file
	   name, the size and the expected MD5 hash. Note that the file name to write to will not always match the file name on
	   the remote site! This also works with the source and update commands. When used with the update command the MD5 and
	   size are not included, and it is up to the user to decompress any compressed files. Configuration Item:
	   APT::Get::Print-URIs.

       --purge
	   Use purge instead of remove for anything that would be removed. An asterisk ("*") will be displayed next to packages
	   which are scheduled to be purged.  remove --purge is equivalent to the purge command. Configuration Item:
	   APT::Get::Purge.

       --reinstall
	   Re-install packages that are already installed and at the newest version. Configuration Item: APT::Get::ReInstall.

       --list-cleanup
	   This option is on by default; use --no-list-cleanup to turn it off. When it is on, apt-get will automatically manage
	   the contents of /var/lib/apt/lists to ensure that obsolete files are erased. The only reason to turn it off is if you
	   frequently change your sources list. Configuration Item: APT::Get::List-Cleanup.

       -t, --target-release, --default-release
	   This option controls the default input to the policy engine; it creates a default pin at priority 990 using the
	   specified release string. This overrides the general settings in /etc/apt/preferences. Specifically pinned packages are
	   not affected by the value of this option. In short, this option lets you have simple control over which distribution
	   packages will be retrieved from. Some common examples might be -t '2.1*', -t unstable or -t sid. Configuration Item:
	   APT::Default-Release; see also the apt_preferences(5) manual page.

       --trivial-only
	   Only perform operations that are 'trivial'. Logically this can be considered related to --assume-yes; where
	   --assume-yes will answer yes to any prompt, --trivial-only will answer no. Configuration Item: APT::Get::Trivial-Only.

       --no-remove
	   If any packages are to be removed apt-get immediately aborts without prompting. Configuration Item: APT::Get::Remove.

       --auto-remove
	   If the command is either install or remove, then this option acts like running the autoremove command, removing unused
	   dependency packages. Configuration Item: APT::Get::AutomaticRemove.

       --only-source
	   Only has meaning for the source and build-dep commands. Indicates that the given source names are not to be mapped
	   through the binary table. This means that if this option is specified, these commands will only accept source package
	   names as arguments, rather than accepting binary package names and looking up the corresponding source package.
	   Configuration Item: APT::Get::Only-Source.

       --diff-only, --dsc-only, --tar-only
	   Download only the diff, dsc, or tar file of a source archive. Configuration Item: APT::Get::Diff-Only,
	   APT::Get::Dsc-Only, and APT::Get::Tar-Only.

       --arch-only
	   Only process architecture-dependent build-dependencies. Configuration Item: APT::Get::Arch-Only.

       --allow-unauthenticated
	   Ignore if packages can't be authenticated and don't prompt about it. This is useful for tools like pbuilder.
	   Configuration Item: APT::Get::AllowUnauthenticated.

       -h, --help
	   Show a short usage summary.

       -v, --version
	   Show the program version.

       -c, --config-file
	   Configuration File; Specify a configuration file to use. The program will read the default configuration file and then
	   this configuration file. If configuration settings need to be set before the default configuration files are parsed
	   specify a file with the APT_CONFIG environment variable. See apt.conf(5) for syntax information.

       -o, --option
	   Set a Configuration Option; This will set an arbitrary configuration option. The syntax is -o Foo::Bar=bar.	-o and
	   --option can be used multiple times to set different options.

FILES
       /etc/apt/sources.list
	   Locations to fetch packages from. Configuration Item: Dir::Etc::SourceList.

       /etc/apt/sources.list.d/
	   File fragments for locations to fetch packages from. Configuration Item: Dir::Etc::SourceParts.

       /etc/apt/apt.conf
	   APT configuration file. Configuration Item: Dir::Etc::Main.

       /etc/apt/apt.conf.d/
	   APT configuration file fragments. Configuration Item: Dir::Etc::Parts.

       /etc/apt/preferences
	   Version preferences file. This is where you would specify "pinning", i.e. a preference to get certain packages from a
	   separate source or from a different version of a distribution. Configuration Item: Dir::Etc::Preferences.

       /etc/apt/preferences.d/
	   File fragments for the version preferences. Configuration Item: Dir::Etc::PreferencesParts.

       /var/cache/apt/archives/
	   Storage area for retrieved package files. Configuration Item: Dir::Cache::Archives.

       /var/cache/apt/archives/partial/
	   Storage area for package files in transit. Configuration Item: Dir::Cache::Archives (partial will be implicitly
	   appended)

       /var/lib/apt/lists/
	   Storage area for state information for each package resource specified in sources.list(5) Configuration Item:
	   Dir::State::Lists.

       /var/lib/apt/lists/partial/
	   Storage area for state information in transit. Configuration Item: Dir::State::Lists (partial will be implicitly
	   appended)

SEE ALSO
       apt-cache(8), apt-cdrom(8), dpkg(1), dselect(1), sources.list(5), apt.conf(5), apt-config(8), apt-secure(8), The APT User's
       guide in /usr/share/doc/apt-doc/, apt_preferences(5), the APT Howto.

DIAGNOSTICS
       apt-get returns zero on normal operation, decimal 100 on error.

BUGS
       APT bug page[3]. If you wish to report a bug in APT, please see /usr/share/doc/debian/bug-reporting.txt or the reportbug(1)
       command.

AUTHORS
       Jason Gunthorpe

       APT team

NOTES
	1. packages.debian.org/changelogs
	   http://packages.debian.org/changelogs

	2. changelogs.ubuntu.com/changelogs
	   http://changelogs.ubuntu.com/changelogs

	3. APT bug page
	   http://bugs.debian.org/src:apt



APT 0.9.7.5ubuntu5.1					   09 June 2012 						APT-GET(8)