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<!ENTITY % aptent SYSTEM "apt.ent">
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<!ENTITY % aptverbatiment SYSTEM "apt-verbatim.ent">
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<refentry>

 <refentryinfo>
   &apt-author.jgunthorpe;
   &apt-author.team;
   &apt-email;
   &apt-product;
   <!-- The last update date -->
   <date>2012-06-09T00:00:00Z</date>
 </refentryinfo>
 
 <refmeta>
   <refentrytitle>apt-get</refentrytitle>
   <manvolnum>8</manvolnum>
   <refmiscinfo class="manual">APT</refmiscinfo>
 </refmeta>
 
 <!-- Man page title -->
 <refnamediv>
    <refname>apt-get</refname>
    <refpurpose>APT package handling utility -- command-line interface</refpurpose>
 </refnamediv>

 &synopsis-command-apt-get;

 <refsect1><title>Description</title>
   <para><command>apt-get</command> 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;,
   &aptitude;, &synaptic; and &wajig;.</para>

   <para>Unless the <option>-h</option>, or <option>--help</option> option is given, one of the
   commands below must be present.</para>
   
   <variablelist>
     <varlistentry><term><option>update</option></term>
     <listitem><para><literal>update</literal> is used to resynchronize the package index files from
     their sources. The indexes of available packages are fetched from the
     location(s) specified in <filename>/etc/apt/sources.list</filename>.
     For example, when using a Debian archive, this command retrieves and
     scans the <filename>Packages.gz</filename> files, so that information about new 
     and updated packages is available. An <literal>update</literal> should always be 
     performed before an <literal>upgrade</literal> or <literal>dist-upgrade</literal>. Please 
     be aware that the overall progress meter will be incorrect as the size 
     of the package files cannot be known in advance.</para></listitem>
     </varlistentry>
     
     <varlistentry><term><option>upgrade</option></term>
     <listitem><para><literal>upgrade</literal> is used to install the newest versions of all packages 
     currently installed on the system from the sources enumerated in
     <filename>/etc/apt/sources.list</filename>. 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 <literal>update</literal> must be 
     performed first so that <command>apt-get</command> knows that new versions of packages are 
     available.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>dist-upgrade</option></term>
     <listitem><para><literal>dist-upgrade</literal> in addition to performing the function of 
     <literal>upgrade</literal>, also intelligently handles changing dependencies 
     with new versions of packages; <command>apt-get</command> 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 <literal>dist-upgrade</literal> command may therefore remove some packages.
     The <filename>/etc/apt/sources.list</filename> file contains a list of locations 
     from which to retrieve desired package files.
     See also &apt-preferences; for a mechanism for
     overriding the general settings for individual packages.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>dselect-upgrade</option></term>
     <listitem><para><literal>dselect-upgrade</literal>
     is used in conjunction with the traditional Debian packaging
     front-end, &dselect;. <literal>dselect-upgrade</literal>
     follows the changes made by &dselect; to the <literal>Status</literal>
     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).</para></listitem>
     </varlistentry>

     <varlistentry><term><option>install</option></term>
     <listitem>
	 <para><literal>install</literal> 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, 
	 <package>apt-utils</package> would be the argument provided, not 
	 <filename>apt-utils_&apt-product-version;_amd64.deb</filename>). All packages required 
	 by the package(s) specified for installation will also 
	 be retrieved and installed. 
	 The <filename>/etc/apt/sources.list</filename> 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.
	 </para>

     <para>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).</para>

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

	<para>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.
	</para>

     <para>Finally, the &apt-preferences; mechanism allows you to
     create an alternative installation policy for
     individual packages.</para>

     <para>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.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>remove</option></term>
     <listitem><para><literal>remove</literal> is identical to <literal>install</literal> 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.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>purge</option></term>
     <listitem><para><literal>purge</literal> is identical to <literal>remove</literal> except that packages are 
     removed and purged (any configuration files are deleted too).</para></listitem>
     </varlistentry>

     <varlistentry><term><option>source</option></term>
     <listitem><para><literal>source</literal> causes <command>apt-get</command> 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 <literal>APT::Default-Release</literal>,
     the <option>-t</option> option or per package with the
     <literal>pkg/release</literal> syntax, if possible.</para>

     <para>Source packages are tracked separately
     from binary packages via <literal>deb-src</literal> lines 
     in the &sources-list; 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.</para>

     <para>If the <option>--compile</option> option is specified
     then the package will be compiled to a binary .deb using
     <command>dpkg-buildpackage</command> for the architecture as
     defined by the <command>--host-architecture</command> option.
     If <option>--download-only</option> is specified then the source package
     will not be unpacked.</para>

     <para>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 
     <literal>APT::Get::Only-Source</literal> option.</para>

     <para>Note that source packages are not installed and tracked in the
     <command>dpkg</command> database like binary packages; they are simply downloaded
     to the current directory, like source tarballs.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>build-dep</option></term>
     <listitem><para><literal>build-dep</literal> 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 <option>--host-architecture</option> option instead.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>check</option></term>
     <listitem><para><literal>check</literal> is a diagnostic tool; it updates the package cache and checks 
     for broken dependencies.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>download</option></term>
       <listitem><para><literal>download</literal> will download the given
           binary package into the current directory.
       </para></listitem>
     </varlistentry>

     <varlistentry><term><option>clean</option></term>
     <listitem><para><literal>clean</literal> clears out the local repository of retrieved package 
     files. It removes everything but the lock file from 
     <filename>&cachedir;/archives/</filename> and 
     <filename>&cachedir;/archives/partial/</filename>. When APT is used as a 
     &dselect; method, <literal>clean</literal> is run automatically.
     Those who do not use dselect will likely want to run <literal>apt-get clean</literal>
     from time to time to free up disk space.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>autoclean</option></term>
     <listitem><para>Like <literal>clean</literal>, <literal>autoclean</literal> 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 
     <literal>APT::Clean-Installed</literal> will prevent installed packages from being
     erased if it is set to off.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>autoremove</option></term>
     <listitem><para><literal>autoremove</literal> is used to remove packages that were automatically
     installed to satisfy dependencies for other packages and are now no longer needed.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>changelog</option></term>
       <listitem><para><literal>changelog</literal> downloads a package changelog and displays
           it through <command>sensible-pager</command>. The server name and base
           directory is defined in the <literal>APT::Changelogs::Server</literal>
	   variable (e.g. <ulink url="http://packages.debian.org/changelogs">packages.debian.org/changelogs</ulink> for
	   Debian or <ulink url="http://changelogs.ubuntu.com/changelogs">changelogs.ubuntu.com/changelogs</ulink> for
           Ubuntu).
           By default it displays the changelog for the version that is
           installed.  However, you can specify the same options as for
           the <option>install</option> command.
         </para>
       </listitem>
     </varlistentry>



   </variablelist>
 </refsect1>
 
 <refsect1><title>options</title>
   &apt-cmdblurb;

   <variablelist>
     <varlistentry><term><option>--no-install-recommends</option></term>
     <listitem><para>Do not consider recommended packages as a dependency for installing.
     Configuration Item: <literal>APT::Install-Recommends</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--install-suggests</option></term>
     <listitem><para>Consider suggested packages as a dependency for installing.
     Configuration Item: <literal>APT::Install-Suggests</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>-d</option></term><term><option>--download-only</option></term>
     <listitem><para>Download only; package files are only retrieved, not unpacked or installed.
     Configuration Item: <literal>APT::Get::Download-Only</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>-f</option></term><term><option>--fix-broken</option></term>
     <listitem><para>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; or <command>dpkg --remove</command> to eliminate some of 
     the offending packages). Use of this option together with <option>-m</option> may produce an
     error in some situations. 
     Configuration Item: <literal>APT::Get::Fix-Broken</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>-m</option></term><term><option>--ignore-missing</option></term>
     <term><option>--fix-missing</option></term>
     <listitem><para>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  
     <option>-f</option> 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: <literal>APT::Get::Fix-Missing</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--no-download</option></term>
     <listitem><para>Disables downloading of packages. This is best used with 
     <option>--ignore-missing</option> to force APT to use only the .debs it has 
     already downloaded.
     Configuration Item: <literal>APT::Get::Download</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>-q</option></term><term><option>--quiet</option></term>
     <listitem><para>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
     <option>-q=#</option> to set the quiet level, overriding the configuration file. 
     Note that quiet level 2 implies <option>-y</option>; 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: <literal>quiet</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>-s</option></term>
                   <term><option>--simulate</option></term>
		   <term><option>--just-print</option></term>
		   <term><option>--dry-run</option></term>
		   <term><option>--recon</option></term>
		   <term><option>--no-act</option></term>
     <listitem><para>No action; perform a simulation of events that would occur but do not
     actually change the system. 
     Configuration Item: <literal>APT::Get::Simulate</literal>.</para>

     <para>Simulated runs performed as a user will automatically deactivate locking
     (<literal>Debug::NoLocking</literal>), and if the option
     <literal>APT::Get::Show-User-Simulation-Note</literal> 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 <literal>apt-get</literal>.</para>

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

     <varlistentry><term><option>-y</option></term><term><option>--yes</option></term>
                   <term><option>--assume-yes</option></term>
     <listitem><para>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 <literal>apt-get</literal> will abort. 
     Configuration Item: <literal>APT::Get::Assume-Yes</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--assume-no</option></term>
     <listitem><para>Automatic "no" to all prompts.
     Configuration Item: <literal>APT::Get::Assume-No</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>-u</option></term><term><option>--show-upgraded</option></term>
     <listitem><para>Show upgraded packages; print out a list of all packages that are to be
     upgraded. 
     Configuration Item: <literal>APT::Get::Show-Upgraded</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>-V</option></term><term><option>--verbose-versions</option></term>
     <listitem><para>Show full versions for upgraded and installed packages.
     Configuration Item: <literal>APT::Get::Show-Versions</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>-a</option></term>
                   <term><option>--host-architecture</option></term>
     <listitem><para>This option controls the architecture packages are built for
     by <command>apt-get source --compile</command> 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 <literal>APT::Architecture</literal>).
     Configuration Item: <literal>APT::Get::Host-Architecture</literal>
     </para></listitem>
     </varlistentry>

     <varlistentry><term><option>-b</option></term><term><option>--compile</option></term>
                   <term><option>--build</option></term>
     <listitem><para>Compile source packages after downloading them.
     Configuration Item: <literal>APT::Get::Compile</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--ignore-hold</option></term>
     <listitem><para>Ignore package holds; this causes <command>apt-get</command> to ignore a hold 
     placed on a package. This may be useful in conjunction with 
     <literal>dist-upgrade</literal> to override a large number of undesired holds. 
     Configuration Item: <literal>APT::Ignore-Hold</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--no-upgrade</option></term>
     <listitem><para>Do not upgrade packages; when used in conjunction with <literal>install</literal>,
     <literal>no-upgrade</literal> will prevent packages on the command line
     from being upgraded if they are already installed.
     Configuration Item: <literal>APT::Get::Upgrade</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--only-upgrade</option></term>
     <listitem><para>Do not install new packages; when used in conjunction
     with <literal>install</literal>, <literal>only-upgrade</literal> will
     install upgrades for already installed packages only and ignore requests
     to install new packages.
     Configuration Item: <literal>APT::Get::Only-Upgrade</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--force-yes</option></term>
     <listitem><para>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 
     <literal>force-yes</literal> can potentially destroy your system! 
     Configuration Item: <literal>APT::Get::force-yes</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--print-uris</option></term>
     <listitem><para>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 
     <literal>source</literal> and <literal>update</literal> commands. When used with the
     <literal>update</literal> command the MD5 and size are not included, and it is
     up to the user to decompress any compressed files.
     Configuration Item: <literal>APT::Get::Print-URIs</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--purge</option></term>
     <listitem><para>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. <option>remove --purge</option> is equivalent to the
	 <option>purge</option> command.
     Configuration Item: <literal>APT::Get::Purge</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--reinstall</option></term>
     <listitem><para>Re-install packages that are already installed and at the newest version.
     Configuration Item: <literal>APT::Get::ReInstall</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--list-cleanup</option></term>
     <listitem><para>This option is on by default; use <literal>--no-list-cleanup</literal> to turn
     it off. When it is on, <command>apt-get</command> will automatically manage the contents
     of <filename>&statedir;/lists</filename> to ensure that obsolete files are erased.
     The only reason to turn it off is if you frequently change your sources list.
     Configuration Item: <literal>APT::Get::List-Cleanup</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>-t</option></term>
                   <term><option>--target-release</option></term>
                   <term><option>--default-release</option></term>
     <listitem><para>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 <filename>/etc/apt/preferences</filename>.
     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 
     <option>-t '2.1*'</option>, <option>-t unstable</option>
     or <option>-t sid</option>.
     Configuration Item: <literal>APT::Default-Release</literal>;
     see also the &apt-preferences; manual page.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--trivial-only</option></term>
     <listitem><para>
     Only perform operations that are 'trivial'. Logically this can be considered
     related to <option>--assume-yes</option>; where <option>--assume-yes</option> will answer 
     yes to any prompt, <option>--trivial-only</option> will answer no. 
     Configuration Item: <literal>APT::Get::Trivial-Only</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--no-remove</option></term>
     <listitem><para>If any packages are to be removed apt-get immediately aborts without
     prompting. 
     Configuration Item: <literal>APT::Get::Remove</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--auto-remove</option></term>
     <listitem><para>If the command is either <literal>install</literal> or <literal>remove</literal>,
     then this option acts like running the <literal>autoremove</literal> command, removing unused
     dependency packages. Configuration Item: <literal>APT::Get::AutomaticRemove</literal>.
     </para></listitem>
     </varlistentry>

     <varlistentry><term><option>--only-source</option></term>
     <listitem><para>Only has meaning for the
     <literal>source</literal> and <literal>build-dep</literal>
     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: <literal>APT::Get::Only-Source</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--diff-only</option></term><term><option>--dsc-only</option></term><term><option>--tar-only</option></term>
     <listitem><para>Download only the diff, dsc, or tar file of a source archive. 
     Configuration Item: <literal>APT::Get::Diff-Only</literal>, <literal>APT::Get::Dsc-Only</literal>, and 
     <literal>APT::Get::Tar-Only</literal>.</para></listitem>
     </varlistentry>
     
     <varlistentry><term><option>--arch-only</option></term>
     <listitem><para>Only process architecture-dependent build-dependencies.
     Configuration Item: <literal>APT::Get::Arch-Only</literal>.</para></listitem>
     </varlistentry>

     <varlistentry><term><option>--allow-unauthenticated</option></term>
     <listitem><para>Ignore if packages can't be authenticated and don't prompt about it.
     This is useful for tools like pbuilder.
     Configuration Item: <literal>APT::Get::AllowUnauthenticated</literal>.</para></listitem>
     </varlistentry>
     

     &apt-commonoptions;
     
   </variablelist>
 </refsect1>

 <refsect1><title>Files</title>
   <variablelist>
     &file-sourceslist;
     &file-aptconf;
     &file-preferences;
     &file-cachearchives;
     &file-statelists;
   </variablelist>
 </refsect1>

 <refsect1><title>See Also</title>
   <para>&apt-cache;, &apt-cdrom;, &dpkg;, &dselect;, &sources-list;,
   &apt-conf;, &apt-config;, &apt-secure;, 
   The APT User's guide in &guidesdir;, &apt-preferences;, the APT Howto.</para>
 </refsect1>

 <refsect1><title>Diagnostics</title>
   <para><command>apt-get</command> returns zero on normal operation, decimal 100 on error.</para>
 </refsect1>
 &manbugs;
</refentry>
