APT-CACHE(8)

NAME

apt-cache - APT package handling utility -- cache manipulator

SYNOPSIS

apt-cache [-hvsn] [-o=config string] [-c=file] {[add file...] |
          [gencaches] | [showpkg pkg...] | [showsrc pkg...] | [stats] |
          [dump] | [dumpavail] | [unmet] | [search regex] |
          [show pkg...] | [depends pkg...] | [rdepends pkg...] |
          [pkgnames prefix] | [dotty pkg...] | [xvcg pkg...] |
          [policy pkgs...] | [madison pkgs...]}

DESCRIPTION

apt-cache performs a variety of operations on APT's package cache. apt-cache does not manipulate the state of the system but does provide operations to search and generate interesting output from the package
metadata.

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

add file(s): add adds the named package index files to the package cache. This
is for debugging only.
gencaches: gencaches performs the same operation as apt-get check. It builds the source and package caches from the sources in sources.list(5) and from /var/lib/dpkg/status.
showpkg pkg(s): showpkg displays information about the packages listed on the
command line. Remaining arguments are package names. The available versions and reverse dependencies of each package listed are
listed, as well as forward dependencies for each version. Forward
(normal) dependencies are those packages upon which the package in question depends; reverse dependencies are those packages that
depend upon the package in question. Thus, forward dependencies
must be satisfied for a package, but reverse dependencies need not be. For instance, apt-cache showpkg libreadline2 would produce output similar to the following:

Package: libreadline2
Versions: 2.1-12(/var/state/apt/lists/foo_Packages),
Reverse Depends:
libreadlineg2,libreadline2
libreadline2-altdev,libreadline2

Dependencies:
2.1-12 - libc5 (2 5.4.0-0) ncurses3.0 (0 (null))
Provides:
2.1-12 Reverse Provides:; Thus it may be seen that libreadline2, version 2.1-12, depends on
libc5 and ncurses3.0 which must be installed for libreadline2 to
work. In turn, libreadlineg2 and libreadline2-altdev depend on
libreadline2. If libreadline2 is installed, libc5 and ncurses3.0
(and ldso) must also be installed; libreadlineg2 and
libreadline2-altdev do not have to be installed. For the specific
meaning of the remainder of the output it is best to consult the
apt source code.
stats: stats displays some statistics about the cache. No further
arguments are expected. Statistics reported are:; o Total package names is the number of package names found in the
cache.; o Normal packages is the number of regular, ordinary package
names; these are packages that bear a one-to-one correspondence between their names and the names used by other packages for
them in dependencies. The majority of packages fall into this
category.; o Pure virtual packages is the number of packages that exist only
as a virtual package name; that is, packages only "provide" the virtual package name, and no package actually uses the name.
For instance, "mail-transport-agent" in the Debian GNU/Linux
system is a pure virtual package; several packages provide
"mail-transport-agent", but there is no package named
"mail-transport-agent".; o Single virtual packages is the number of packages with only one
package providing a particular virtual package. For example, in the Debian GNU/Linux system, "X11-text-viewer" is a virtual
package, but only one package, xless, provides
"X11-text-viewer".; o Mixed virtual packages is the number of packages that either
provide a particular virtual package or have the virtual
package name as the package name. For instance, in the Debian
GNU/Linux system, "debconf" is both an actual package, and
provided by the debconf-tiny package.; o Missing is the number of package names that were referenced in
a dependency but were not provided by any package. Missing
packages may be an evidence if a full distribution is not
accessed, or if a package (real or virtual) has been dropped
from the distribution. Usually they are referenced from
Conflicts or Breaks statements.; o Total distinct versions is the number of package versions found
in the cache; this value is therefore at least equal to the
number of total package names. If more than one distribution
(both "stable" and "unstable", for instance), is being
accessed, this value can be considerably larger than the number of total package names.; o Total dependencies is the number of dependency relationships
claimed by all of the packages in the cache.
showsrc pkg(s): showsrc displays all the source package records that match the
given package names. All versions are shown, as well as all records that declare the name to be a Binary.
dump: dump shows a short listing of every package in the cache. It is
primarily for debugging.
dumpavail: dumpavail prints out an available list to stdout. This is suitable for use with dpkg(1) and is used by the dselect(1) method.
unmet: unmet displays a summary of all unmet dependencies in the package
cache.
show pkg(s): show performs a function similar to dpkg --print-avail; it displays the package records for the named packages.
search regex [ regex ... ]: search performs a full text search on all available package lists
for the POSIX regex pattern given, see regex(7). It searches the package names and the descriptions for an occurrence of the regular expression and prints out the package name and the short
description, including virtual package names. If --full is given then output identical to show is produced for each matched package, and if --names-only is given then the long description is not searched, only the package name is.; Separate arguments can be used to specify multiple search patterns that are and'ed together.
depends pkg(s): depends shows a listing of each dependency a package has and all
the possible other packages that can fulfill that dependency.
rdepends pkg(s): rdepends shows a listing of each reverse dependency a package has.
pkgnames [ prefix ]: This command prints the name of each package APT knows. The
optional argument is a prefix match to filter the name list. The
output is suitable for use in a shell tab complete function and the output is generated extremely quickly. This command is best used
with the --generate option.; Note that a package which APT knows of is not necessarily available to download, installable or installed, e.g. virtual packages are
also listed in the generated list.
dotty pkg(s): dotty takes a list of packages on the command line and generates
output suitable for use by dotty from the GraphViz[1] package. The result will be a set of nodes and edges representing the
relationships between the packages. By default the given packages
will trace out all dependent packages; this can produce a very
large graph. To limit the output to only the packages listed on the command line, set the APT::Cache::GivenOnly option.; The resulting nodes will have several shapes; normal packages are
boxes, pure provides are triangles, mixed provides are diamonds,
missing packages are hexagons. Orange boxes mean recursion was
stopped [leaf packages], blue lines are pre-depends, green lines
are conflicts.; Caution, dotty cannot graph larger sets of packages.
xvcg pkg(s): The same as dotty, only for xvcg from the VCG tool[2].
policy [ pkg(s) ]: policy is meant to help debug issues relating to the preferences
file. With no arguments it will print out the priorities of each
source. Otherwise it prints out detailed information about the
priority selection of the named package.
madison /[ pkg(s) ]: apt-cache's madison command attempts to mimic the output format and a subset of the functionality of the Debian archive management
tool, madison. It displays available versions of a package in a
tabular format. Unlike the original madison, it can only display
information for the architecture for which APT has retrieved
package lists (APT::Architecture).

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.

-p, --pkg-cache: Select the file to store the package cache. The package cache is
the primary cache used by all operations. Configuration Item:
Dir::Cache::pkgcache.
-s, --src-cache: Select the file to store the source cache. The source is used only by gencaches and it stores a parsed version of the package
information from remote sources. When building the package cache
the source cache is used to avoid reparsing all of the package
files. Configuration Item: Dir::Cache::srcpkgcache.
-q, --quiet: Quiet; produces output suitable for logging, omitting progress
indicators. More q's will produce more quietness up to a maximum of 2. You can also use -q=# to set the quietness level, overriding the configuration file. Configuration Item: quiet.
-i, --important
Print only important dependencies; for use with unmet and depends. Causes only Depends and Pre-Depends relations to be printed.
Configuration Item: APT::Cache::Important.
--no-pre-depends, --no-depends, --no-recommends, --no-suggests, --no-conflicts, --no-breaks, --no-replaces, --no-enhances Per default the depends and rdepends print all dependencies. This
can be twicked with these flags which will omit the specified
dependency type. Configuration Item: APT::Cache::ShowDependencyType e.g. APT::Cache::ShowRecommends.
-f, --full
Print full package records when searching. Configuration Item:
APT::Cache::ShowFull.
-a, --all-versions
Print full records for all available versions. This is the default;
to turn it off, use --no-all-versions. If --no-all-versions is specified, only the candidate version will displayed (the one which would be selected for installation). This option is only applicable to the show command. Configuration Item: APT::Cache::AllVersions.
-g, --generate
Perform automatic package cache regeneration, rather than use the
cache as it is. This is the default; to turn it off, use
--no-generate. Configuration Item: APT::Cache::Generate.
--names-only, -n
Only search on the package names, not the long descriptions.
Configuration Item: APT::Cache::NamesOnly.
--all-names
Make pkgnames print all names, including virtual packages and
missing dependencies. Configuration Item: APT::Cache::AllNames.
--recurse
Make depends and rdepends recursive so that all packages mentioned are printed once. Configuration Item: APT::Cache::RecurseDepends.
--installed
Limit the output of depends and rdepends to packages which are
currently installed. Configuration Item: APT::Cache::Installed.
-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.
/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 (implicit partial).

DIAGNOSTICS

apt-cache 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. GraphViz: http://www.research.att.com/sw/tools/graphviz/; 2. VCG tool
http://rw4.cs.uni-sb.de/users/sander/html/gsvcg1.html; 3. APT bug page
http://bugs.debian.org/src:apt

docs.sk

comprehensive documentation repository

See also