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e.g. apt-get, so that it can be outdated if the last update is too long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 creates APT's package cache. This is done
implicitly by all commands needing this cache if it is missing or
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:
2.1-12 - libc5 (2 5.4.0-0) ncurses3.0 (0 (null))
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
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
•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
•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 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 shows a short listing of every package in the cache.
It is primarily for debugging.
dumpavail prints out an available list to stdout. This is
suitable for use with dpkg(1)
and is used by the dselect(1)
unmet displays a summary of all unmet dependencies in the
show performs a function similar to dpkg
--print-avail; it displays the package records for the named
search performs a full text search on all available
package lists for the POSIX regex pattern given, see regex(7)
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
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 shows a listing of each dependency a package has
and all the possible other packages that can fulfill that dependency.
rdepends shows a listing of each reverse dependency a
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
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 takes a list of packages on the command line and
generates output suitable for use by dotty from the GraphViz
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
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
Caution, dotty cannot graph larger sets of packages.
The same as dotty, only for xvcg from the VCG
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.
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
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.
Select the file to store the package cache. The package
cache is the primary cache used by all operations. Configuration Item:
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:
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.
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-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.
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:
Print full package records when searching. Configuration
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:
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.
Only search on the package and provided package names,
not the long descriptions. Configuration Item: APT::Cache::NamesOnly.
Make pkgnames print all names, including virtual packages
and missing dependencies. Configuration Item: APT::Cache::AllNames.
Make depends and rdepends recursive so that all packages
mentioned are printed once. Configuration Item:
Limit the output of depends and rdepends to packages
which are currently installed. Configuration Item:
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:
Note that these sources are treated as trusted (see
apt-secure(8)). Configuration Item: APT::Sources::With.
Show a short usage summary.
Show the program version.
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
environment variable. See apt.conf(5)
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.