Provided by: apt_1.6.17_amd64 
NAME
apt-cache - query the APT cache
SYNOPSIS
apt-cache [-agipns] [-o=config_string] [-c=config_file] {gencaches | showpkg pkg... | showsrc pkg... |
stats | dump | dumpavail | unmet | search regex... |
show pkg [{=pkg_version_number | /target_release}]... |
depends pkg [{=pkg_version_number | /target_release}]... |
rdepends pkg [{=pkg_version_number | /target_release}]... | pkgnames [prefix] |
dotty pkg [{=pkg_version_number | /target_release}]... |
xvcg pkg [{=pkg_version_number | /target_release}]... | policy [pkg...] | madison pkg... |
{-v | --version} | {-h | --help}}
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. The metadata is acquired and updated via the 'update' command of e.g. apt-get, so that
it can be outdated if the last update is too long ago, but in exchange apt-cache works independently of
the availability of the configured sources (e.g. offline).
Unless the -h, or --help option is given, one of the commands below must be present.
gencaches
gencaches creates APT's package cache. This is done implicitly by all commands needing this cache if
it is missing or outdated.
showpkg pkg...
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:
• Total package names is the number of package names found in the cache.
• 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.
• 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 system is a pure virtual package; several packages
provide "mail-transport-agent", but there is no package named "mail-transport-agent".
• Single virtual packages is the number of packages with only one package providing a particular
virtual package. For example, in the Debian system, "X11-text-viewer" is a virtual package, but
only one package, xless, provides "X11-text-viewer".
• 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 system,
"debconf" is both an actual package, and provided by the debconf-tiny package.
• 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.
• Total distinct versions is the number of package versions found in the cache. If more than one
distribution is being accessed (for instance, "stable" and "unstable"), this value can be
considerably larger than the number of total package names.
• Total dependencies is the number of dependency relationships claimed by all of the packages in
the cache.
showsrc pkg...
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 package. Use --only-source to
display only source package names.
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...
show performs a function similar to dpkg --print-avail; it displays the package records for the named
packages.
search 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 and provided
packages are.
Separate arguments can be used to specify multiple search patterns that are and'ed together.
depends pkg...
depends shows a listing of each dependency a package has and all the possible other packages that can
fulfill that dependency.
rdepends pkg...
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...
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 virtual packages are
triangles, mixed virtual packages 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...
The same as dotty, only for xvcg from the VCG tool[2].
policy [pkg...]
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...
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 tweaked with these flags
which will omit the specified dependency type. Configuration Item: APT::Cache::ShowDependencyType
e.g. APT::Cache::ShowRecommends.
--implicit
Per default depends and rdepends print only dependencies explicitly expressed in the metadata. With
this flag it will also show dependencies implicitly added based on the encountered data. A Conflicts:
foo e.g. expresses implicitly that this package also conflicts with the package foo from any other
architecture. Configuration Item: APT::Cache::ShowImplicit.
-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 be 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 and provided 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.
--with-source filename
Adds the given file as a source for metadata. Can be repeated to add multiple files. Supported are
currently *.deb, *.dsc, *.changes, Sources and Packages files as well as source package directories.
Files are matched based on their name only, not their content!
Sources and Packages can be compressed in any format apt supports as long as they have the correct
extension. If you need to store multiple of these files in one directory you can prefix a name of
your choice with the last character being an underscore ("_"). Example: my.example_Packages.xz
Note that these sources are treated as trusted (see apt-secure(8)). Configuration Item:
APT::Sources::With.
-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 (partial will be
implicitly appended)
SEE ALSO
apt.conf(5), sources.list(5), apt-get(8)
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