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NAME    [Toc]    [Back]

       apt.conf - Configuration file for APT

DESCRIPTION    [Toc]    [Back]

       apt.conf is the main configuration file for the APT suite of tools, all
       tools make use of the configuration file  and  a  common  command  line
       parser  to provide a uniform environment. When an APT tool starts up it
       will read the configuration specified  by  the  APT_CONFIG  environment
       variable  (if any) and then read the files in Dir::Etc::Parts then read
       the main configuration file specified by  Dir::Etc::main  then  finally
       apply  the  command  line  options to override the configuration directives,
 possibly loading even more config files.

       The configuration file is organized in a tree  with  options  organized
       into  functional  groups.  Option  specification is given with a double
       colon notation, for instance APT::Get::Assume-Yes is an	option	within
       the APT tool group, for the Get tool. Options do not inherit from their
       parent groups.

       Syntacticly the configuration language is modeled after	what  the  ISC
       tools such as bind and dhcp use. Each line is of the form

       APT::Get::Assume-Yes "true";

       The  trailing  semicolon is required and the quotes are optional. A new
       scope can be opened with curly braces, like:

       APT {
	 Get {
	   Assume-Yes "true";
	   Fix-Broken "true";

       with newlines placed to make it more readable. Lists can be created  by
       opening a scope and including a single word enclosed in quotes followed
       by a semicolon. Multiple entries can be included, each seperated  by  a

       DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";};

       In  general  the sample configuration file in /usr/share/doc/apt//exam-
       ples/apt.conf /usr/share/doc/apt/examples/configure-index.gz is a  good
       guide for how it should look.

       Two  specials  are allowed, #include and #clear.  #include will include
       the given file, unless the filename ends in a  slash,  then  the  whole
       directory is included.  #clear is used to erase a list of names.

       All of the APT tools take a -o option which allows an arbitary configuration
 directive to be specified on the command line. The syntax  is  a
       full  option  name  (APT::Get::Assume-Yes  for instance) followed by an
       equals sign then the new value of the option. Lists can be appended too
       by adding a trailing :: to the list name.

THE APT GROUP    [Toc]    [Back]

       This  group of options controls general APT behavoir as well as holding
       the options for all of the tools.

       Architecture    [Toc]    [Back]
	      System Architecture; sets the architecture to use when  fetching
	      files  and  parsing  package  lists. The internal default is the
	      architecture apt was compiled for.

       Ignore-Hold    [Toc]    [Back]
	      Ignore Held packages; This  global  option  causes  the  problem
	      resolver to ignore held packages in its decision making.

       Clean-Installed    [Toc]    [Back]
	      Defaults to on. When turned on the autoclean feature will remove
	      any pacakge which can no longer be downloaded from the cache. If
	      turned  off  then  packages  that are locally installed are also
	      excluded from cleaning - but note that APT  provides  no	direct
	      means to reinstall them.

       Immediate-Configure    [Toc]    [Back]
	      Disable  Immedate  Configuration; This dangerous option disables
	      some of APT's ordering code to  cause  it  to  make  fewer  dpkg
	      calls.  Doing  so may be necessary on some extremely slow single
	      user systems but is very dangerous and may cause package install
	      scripts to fail or worse.  Use at your own risk.

       Force-LoopBreak    [Toc]    [Back]
	      Never  Enable  this option unless you -really- know what you are
	      doing. It permits APT to temporarily remove an essential package
	      to  break  a  Conflicts/Conflicts  or  Conflicts/Pre-Depend loop
	      between two essential packages. SUCH A LOOP SHOULD  NEVER  EXIST
	      AND IS A GRAVE BUG. This option will work if the essential packages
 are not tar, gzip, libc, dpkg, bash or anything that  those
	      packages depend on.

       Cache-Limit    [Toc]    [Back]
	      APT  uses  a  fixed  size  memory mapped cache file to store the
	      'available' information. This sets the size of that cache.

       Get    The Get subsection controls the apt-get(8) tool, please see  its
	      documentation for more information about the options here.

       Cache  The  Cache subsection controls the apt-cache(8) tool, please see
	      its documentation for more information about the options here.

       CDROM  The CDROM subsection controls the apt-cdrom(8) tool, please  see
	      its documentation for more information about the options here.

THE ACQUIRE GROUP    [Toc]    [Back]

       The  Acquire group of options controls the download of packages and the
       URI handlers.

       Queue-Mode    [Toc]    [Back]
	      Queuing mode; Queue-Mode can be one  of  host  or  access  which
	      determines how APT parallelizes outgoing connections. host means
	      that one connection per target host will be opened, access means
	      that one connection per URI type will be opened.

       Retries    [Toc]    [Back]
	      Number of retries to perform. If this is non-zero APT will retry
	      failed files the given number of times.

       Source-Symlinks    [Toc]    [Back]
	      Use symlinks for source archives. If set to true then source archives
  will be symlinked when possible instead of copying. True
	      is the default

       http   HTTP URIs; http::Proxy is the default http proxy to use.	It  is
	      in the standard form of http://[[user][:pass]@]host[:port]/. Per
	      host  proxies  can  also	be  specified  by   using   the   form
	      http::Proxy::<host>  with  the special keyword DIRECT meaning to
	      use no proxies. The http_proxy environment variable  will  override
 all settings.

	      Three settings are provided for cache control with HTTP/1.1 complient
 proxy caches. No-Cache tells the proxy to	not  used  its
	      cached  response	under  any circumstances, Max-Age is sent only
	      for index files and tells the cache to refresh its object if  it
	      is  older  than  the given number of seconds. Debian updates its
	      index files daily so the default is 1  day.  No-Store  specifies
	      that  the  cache should never store this request, it is only set
	      for archive files. This may be useful  to  prevent  polluting  a
	      proxy  cache  with very large .deb files. Note: Squid 2.0.2 does
	      not support any of these options.

	      The option timeout sets the timeout timer used  by  the  method,
	      this applies to all things including connection timeout and data

	      One setting is provided to control the pipeline depth  in  cases
	      where  the remote server is not RFC conforming or buggy (such as
	      Squid 2.0.2) Acquire::http::Pipeline-Depth can be a value from 0
	      to 5 indicating how many outstanding requests APT should send. A
	      value of zero MUST be specified if  the  remote  host  does  not
	      properly	linger	on TCP connections - otherwise data corruption
	      will occur. Hosts which require this are	in  violation  of  RFC

       ftp    FTP  URIs;  ftp::Proxy is the default proxy server to use. It is
	      in the standard form of  ftp://[[user][:pass]@]host[:port]/  and
	      is overriden by the ftp_proxy environment variable. To use a ftp
	      proxy you will have to set the  ftp::ProxyLogin  script  in  the
	      configuration file. This entry specifies the commands to send to
	      tell  the  proxy	server	what  to  connect   to.   Please   see
	      /usr/share/doc/apt/examples/configure-index.gz for an example of
	      how  to  do  this.  The  subsitution  variables  available   are
	      $(SITE), and $(SITE_PORT).  Each is taken from  it's  respective
	      URI component.

	      The  option  timeout  sets the timeout timer used by the method,
	      this applies to all things including connection timeout and data

	      Several settings are provided to control passive mode. Generally
	      it is safe to leave passive mode on, it works  in  nearly  every
	      environment.   However some situations require that passive mode
	      be disabled and port mode ftp used instead.  This  can  be  done
	      globally,  for connections that go through a proxy or for a specific
 host (See the sample config file for examples)

	      It is possible to proxy FTP over HTTP by setting	the  ftp_proxy
	      environment  variable  to a http url - see the discussion of the
	      http method above for syntax. You cannot set this in the configuration
  file and it is not recommended to use FTP over HTTP due
	      to its low efficiency.

	      The setting ForceExtended controls the use of RFC2428  EPSV  and
	      EPRT  commands.  The defaut is false, which means these commands
	      are only used if the control connection is IPv6. Setting this to
	      true  forces  their use even on IPv4 connections. Note that most
	      FTP servers do not support RFC2428.

       cdrom  CDROM URIs; the only setting for CDROM URIs is the mount	point,
	      cdrom::Mount  which  must be the mount point for the CDROM drive
	      as specified in /etc/fstab. It is possible to provide  alternate
	      mount  and unmount commands if your mount point cannot be listed
	      in the fstab (such as an SMB mount and old mount packages).  The
	      syntax is to put

	      "/cdrom/"::Mount "foo";

	      within  the  cdrom  block.  It is important to have the trailing
	      slash. Unmount commands can be specified using UMount.

DIRECTORIES    [Toc]    [Back]

       The Dir::State section has directories  that  pertain  to  local  state
       information.  lists  is the directory to place downloaded package lists
       in and status is the name of the dpkg status file.  preferences is  the
       name  of  the  APT  preferences	file.  Dir::State contains the default
       directory to prefix on all sub items if they do not start with / or ./.

       Dir::Cache  contains  locations	pertaining to local cache information,
       such as the two package caches srcpkgcache and pkgcache as well as  the
       location to place downloaded archives, Dir::Cache::archives. Generation
       of caches can be turned off by setting their names to  be  blank.  This
       will  slow down startup but save disk space. It is probably prefered to
       turn off the pkgcache rather than the srcpkgcache. Like Dir::State  the
       default directory is contained in Dir::Cache

       Dir::Etc contains the location of configuration files, sourcelist gives
       the location of the sourcelist and main is  the	default  configuration
       file  (setting  has  no	effect, unless it is done from the config file
       specified by APT_CONFIG).

       The Dir::Parts setting reads in all the	config	fragments  in  lexical
       order  from  the  directory specified. After this is done then the main
       config file is loaded.

       Binary programs are pointed to by Dir::Bin. methods specifies the location
 of the method handlers and gzip, dpkg, apt-get, dpkg-source, dpkgbuildpackage
 and apt-cache specify the location of the respective  programs.

APT IN DSELECT    [Toc]    [Back]

       When  APT  is  used as a dselect(8) method several configuration directives
 control the default behaviour. These are in the DSelect  section.

       Clean  Cache Clean mode; this value may be one of always, prompt, auto,
	      pre-auto and never. always and prompt will remove  all  packages
	      from  the  cache	after  upgrading, prompt (the default) does so
	      conditionally.  auto removes only those packages	which  are  no
	      longer  downloadable (replaced with a new version for instance).
	      pre-auto performs this action before downloading new packages.

       Options    [Toc]    [Back]
	      The contents of this variable is passed to apt-get(8) as command
	      line options when it is run for the install phase.

       UpdateOptions    [Toc]    [Back]
	      The contents of this variable is passed to apt-get(8) as command
	      line options when it is run for the update phase.

       PromptAfterUpdate    [Toc]    [Back]
	      If true the [U]pdate operation in dselect(8) will always	prompt
	      to continue.  The default is to prompt only on error.

HOW APT CALLS DPKG    [Toc]    [Back]

       Several configuration directives control how APT invokes dpkg(8). These
       are in the DPkg section.

       Options    [Toc]    [Back]
	      This is a list of options to pass to dpkg. The options  must  be
	      specified  using	the list notation and each list item is passed
	      as a single argument to dpkg(8).

       Pre-Invoke    [Toc]    [Back]

       Post-Invoke    [Toc]    [Back]
	      This is a list of shell commands to  run	before/after  invoking
	      dpkg(8).	 Like Options this must be specified in list notation.
	      The commands are invoked in order using /bin/sh, should any fail
	      APT will abort.

       Pre-Install-Pkgs    [Toc]    [Back]
	      This  is	a  list of shell commands to run before invoking dpkg.
	      Like Options this must be specified in list notation.  The  commands
  are  invoked  in order using /bin/sh, should any fail APT
	      will abort. APT will pass to the commands on standard input  the
	      filenames  of  all  .deb	files  it is going to install, one per

	      Version 2 of this protocol dumps more information, including the
	      protocol	version, the APT configuration space and the packages,
	      files and versions being changed. Version 2 is enabled  by  setting
  DPkg::Tools::Options::cmd::Version	to 2. cmd is a command
	      given to Pre-Install-Pkgs.

       Run-Directory    [Toc]    [Back]
	      APT chdirs to this directory before invoking dpkg,  the  default
	      is /.

       Build-Options    [Toc]    [Back]
	      These  options are passed to dpkg-buildpackage(1) when compiling
	      packages, the default is to  disable  signing  and  produce  all

DEBUG OPTIONS    [Toc]    [Back]

       Most  of  the  options  in the debug section are not interesting to the
       normal user, however Debug::pkgProblemResolver shows interesting output
       about the decisions dist-upgrade makes.	Debug::NoLocking disables file
       locking so APT can do some operations as non-root and  Debug::pkgDPkgPM
       will   print   out   the   command   line  for  each  dpkg  invokation.
       Debug::IdentCdrom will disable the inclusion of statfs  data  in  CDROM

EXAMPLES    [Toc]    [Back]

       /usr/share/doc/apt/examples/configure-index.gz  contains  a sample configuration
 file showing the default values for all possible options.

FILES    [Toc]    [Back]


SEE ALSO    [Toc]    [Back]

       apt-cache(8), apt-config(8), apt_preferences(5).

BUGS    [Toc]    [Back]

       See the APT bug page <URL:http://bugs.debian.org/apt>.  If you wish  to
       report a bug in APT, please see /usr/share/doc/debian/bug-reporting.txt
       or the bug(1) command.

AUTHOR    [Toc]    [Back]

       APT was written by the APT team <apt@packages.debian.org>.

				 12 March 2001			   APT.CONF(5)
[ Back ]
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