1 <?xml version=
"1.0" encoding=
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"no"?>
2 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
5 <!ENTITY % aptent SYSTEM
"apt.ent">
8 <!ENTITY % aptverbatiment SYSTEM
"apt-verbatim.ent">
16 &apt-author.jgunthorpe;
20 <!-- The last update date -->
21 <date>04 February
2011</date>
25 <refentrytitle>apt-cache
</refentrytitle>
26 <manvolnum>8</manvolnum>
27 <refmiscinfo class=
"manual">APT
</refmiscinfo>
30 <!-- Man page title -->
32 <refname>apt-cache
</refname>
33 <refpurpose>query the APT cache
</refpurpose>
36 &synopsis-command-apt-cache;
38 <refsect1><title>Description
</title>
39 <para><command>apt-cache
</command> performs a variety of operations on APT's package
40 cache.
<command>apt-cache
</command> does not manipulate the state of the system
41 but does provide operations to search and generate interesting output
42 from the package metadata.
</para>
44 <para>Unless the
<option>-h
</option>, or
<option>--help
</option> option is given, one of the
45 commands below must be present.
</para>
48 <varlistentry><term>gencaches
</term>
49 <listitem><para><literal>gencaches
</literal> performs the same operation as
50 <command>apt-get check
</command>. It builds the source and package caches from
51 the sources in &sources-list; and from
52 <filename>/var/lib/dpkg/status
</filename>.
</para></listitem>
55 <varlistentry><term>showpkg
<replaceable>pkg(s)
</replaceable></term>
56 <listitem><para><literal>showpkg
</literal> displays information about the packages listed on the
57 command line. Remaining arguments are package names. The available
58 versions and reverse dependencies of each package listed are listed, as
59 well as forward dependencies for each version. Forward (normal)
60 dependencies are those packages upon which the package in question
61 depends; reverse dependencies are those packages that depend upon the
62 package in question. Thus, forward dependencies must be satisfied for a
63 package, but reverse dependencies need not be.
64 For instance,
<command>apt-cache showpkg libreadline2
</command> would produce
65 output similar to the following:
</para>
67 <informalexample><programlisting>
69 Versions:
2.1-
12(/var/state/apt/lists/foo_Packages),
71 libreadlineg2,libreadline2
72 libreadline2-altdev,libreadline2
74 2.1-
12 - libc5 (
2 5.4.0-
0) ncurses3.0 (
0 (null))
78 </programlisting></informalexample>
80 <para>Thus it may be seen that libreadline2, version
2.1-
12, depends on
81 libc5 and ncurses3.0 which must be installed for libreadline2 to work.
82 In turn, libreadlineg2 and libreadline2-altdev depend on libreadline2. If
83 libreadline2 is installed, libc5 and ncurses3.0 (and ldso) must also be
84 installed; libreadlineg2 and libreadline2-altdev do not have to be
85 installed. For the specific meaning of the remainder of the output it
86 is best to consult the apt source code.
</para></listitem>
89 <varlistentry><term>stats
</term><listitem><para><literal>stats
</literal> displays some statistics about the cache.
90 No further arguments are expected. Statistics reported are:
92 <listitem><para><literal>Total package names
</literal> is the number of package names found
96 <listitem><para><literal>Normal packages
</literal> is the number of regular, ordinary package
97 names; these are packages that bear a one-to-one correspondence between
98 their names and the names used by other packages for them in
99 dependencies. The majority of packages fall into this category.
</para>
102 <listitem><para><literal>Pure virtual packages
</literal> is the number of packages that exist
103 only as a virtual package name; that is, packages only "provide" the
104 virtual package name, and no package actually uses the name. For
105 instance, "mail-transport-agent" in the Debian GNU/Linux system is a
106 pure virtual package; several packages provide "mail-transport-agent",
107 but there is no package named "mail-transport-agent".
</para>
110 <listitem><para><literal>Single virtual packages
</literal> is the number of packages with only
111 one package providing a particular virtual package. For example, in the
112 Debian GNU/Linux system, "X11-text-viewer" is a virtual package, but
113 only one package, xless, provides "X11-text-viewer".
</para>
116 <listitem><para><literal>Mixed virtual packages
</literal> is the number of packages that either
117 provide a particular virtual package or have the virtual package name
118 as the package name. For instance, in the Debian GNU/Linux system,
119 "debconf" is both an actual package, and provided by the debconf-tiny
123 <listitem><para><literal>Missing
</literal> is the number of package names that were referenced in
124 a dependency but were not provided by any package. Missing packages may
125 be an evidence if a full distribution is not accessed, or if a package
126 (real or virtual) has been dropped from the distribution. Usually they
127 are referenced from Conflicts or Breaks statements.
</para>
130 <listitem><para><literal>Total distinct
</literal> versions is the number of package versions
131 found in the cache; this value is therefore at least equal to the
132 number of total package names. If more than one distribution (both
133 "stable" and "unstable", for instance), is being accessed, this value
134 can be considerably larger than the number of total package names.
</para>
137 <listitem><para><literal>Total dependencies
</literal> is the number of dependency relationships
138 claimed by all of the packages in the cache.
</para>
144 <varlistentry><term>showsrc
<replaceable>pkg(s)
</replaceable></term>
145 <listitem><para><literal>showsrc
</literal> displays all the source package records that match
146 the given package names. All versions are shown, as well as all
147 records that declare the name to be a Binary.
</para></listitem>
150 <varlistentry><term>dump
</term>
151 <listitem><para><literal>dump
</literal> shows a short listing of every package in the cache. It is
152 primarily for debugging.
</para></listitem>
155 <varlistentry><term>dumpavail
</term>
156 <listitem><para><literal>dumpavail
</literal> prints out an available list to stdout. This is
157 suitable for use with
&dpkg; and is used by the
&dselect; method.
</para></listitem>
160 <varlistentry><term>unmet
</term>
161 <listitem><para><literal>unmet
</literal> displays a summary of all unmet dependencies in the
162 package cache.
</para></listitem>
165 <varlistentry><term>show
<replaceable>pkg(s)
</replaceable></term>
166 <listitem><para><literal>show
</literal> performs a function similar to
167 <command>dpkg --print-avail
</command>; it displays the package records for the
168 named packages.
</para></listitem>
171 <varlistentry><term>search
<replaceable>regex [ regex ... ]
</replaceable></term>
172 <listitem><para><literal>search
</literal> performs a full text search on all available package
173 lists for the POSIX regex pattern given, see
174 <citerefentry><refentrytitle><command>regex
</command></refentrytitle>
175 <manvolnum>7</manvolnum></citerefentry>.
176 It searches the package names and the
177 descriptions for an occurrence of the regular expression and prints out
178 the package name and the short description, including virtual package
180 If
<option>--full
</option> is given
181 then output identical to
<literal>show
</literal> is produced for each matched
182 package, and if
<option>--names-only
</option> is given then the long description
183 is not searched, only the package name is.
</para>
185 Separate arguments can be used to specify multiple search patterns that
186 are and'ed together.
</para></listitem>
189 <varlistentry><term>depends
<replaceable>pkg(s)
</replaceable></term>
190 <listitem><para><literal>depends
</literal> shows a listing of each dependency a package has
191 and all the possible other packages that can fulfill that dependency.
</para></listitem>
194 <varlistentry><term>rdepends
<replaceable>pkg(s)
</replaceable></term>
195 <listitem><para><literal>rdepends
</literal> shows a listing of each reverse dependency a
196 package has.
</para></listitem>
199 <varlistentry><term>pkgnames
<replaceable>[ prefix ]
</replaceable></term>
200 <listitem><para>This command prints the name of each package APT knows. The optional
201 argument is a prefix match to filter the name list. The output is suitable
202 for use in a shell tab complete function and the output is generated
203 extremely quickly. This command is best used with the
204 <option>--generate
</option> option.
</para>
205 <para>Note that a package which APT knows of is not necessarily available to download,
206 installable or installed, e.g. virtual packages are also listed in the generated list.
210 <varlistentry><term>dotty
<replaceable>pkg(s)
</replaceable></term>
211 <listitem><para><literal>dotty
</literal> takes a list of packages on the command line and
212 generates output suitable for use by dotty from the
213 <ulink url=
"http://www.research.att.com/sw/tools/graphviz/">GraphViz
</ulink>
214 package. The result will be a set of nodes and edges representing the
215 relationships between the packages. By default the given packages will
216 trace out all dependent packages; this can produce a very large graph.
217 To limit the output to only the packages listed on the command line,
218 set the
<literal>APT::Cache::GivenOnly
</literal> option.
</para>
220 <para>The resulting nodes will have several shapes; normal packages are boxes,
221 pure provides are triangles, mixed provides are diamonds,
222 missing packages are hexagons. Orange boxes mean recursion was stopped
223 [leaf packages], blue lines are pre-depends, green lines are conflicts.
</para>
225 <para>Caution, dotty cannot graph larger sets of packages.
</para></listitem>
228 <varlistentry><term>xvcg
<replaceable>pkg(s)
</replaceable></term>
229 <listitem><para>The same as
<literal>dotty
</literal>, only for xvcg from the
230 <ulink url=
"http://rw4.cs.uni-sb.de/users/sander/html/gsvcg1.html">VCG tool
</ulink>.
231 </para></listitem></varlistentry>
233 <varlistentry><term>policy
<replaceable>[ pkg(s) ]
</replaceable></term>
234 <listitem><para><literal>policy
</literal> is meant to help debug issues relating to the
235 preferences file. With no arguments it will print out the
236 priorities of each source. Otherwise it prints out detailed information
237 about the priority selection of the named package.
</para></listitem>
240 <varlistentry><term>madison
<replaceable>[ pkg(s) ]
</replaceable></term>
241 <listitem><para><literal>apt-cache
</literal>'s
<literal>madison
</literal> command attempts to mimic
242 the output format and a subset of the functionality of the Debian
243 archive management tool,
<literal>madison
</literal>. It displays
244 available versions of a package in a tabular format. Unlike the
245 original
<literal>madison
</literal>, it can only display information for
246 the architecture for which APT has retrieved package lists
247 (
<literal>APT::Architecture
</literal>).
</para></listitem>
252 <refsect1><title>options
</title>
256 <varlistentry><term><option>-p
</option></term><term><option>--pkg-cache
</option></term>
257 <listitem><para>Select the file to store the package cache. The package cache is the
258 primary cache used by all operations.
259 Configuration Item:
<literal>Dir::Cache::pkgcache
</literal>.
</para></listitem>
262 <varlistentry><term><option>-s
</option></term><term><option>--src-cache
</option></term>
263 <listitem><para>Select the file to store the source cache. The source is used only by
264 <literal>gencaches
</literal> and it stores a parsed version of the package
265 information from remote sources. When building the package cache the
266 source cache is used to avoid reparsing all of the package files.
267 Configuration Item:
<literal>Dir::Cache::srcpkgcache
</literal>.
</para></listitem>
270 <varlistentry><term><option>-q
</option></term><term><option>--quiet
</option></term>
271 <listitem><para>Quiet; produces output suitable for logging, omitting progress indicators.
272 More q's will produce more quietness up to a maximum of
2. You can also use
273 <option>-q=#
</option> to set the quietness level, overriding the configuration file.
274 Configuration Item:
<literal>quiet
</literal>.
</para></listitem>
277 <varlistentry><term><option>-i
</option></term><term><option>--important
</option></term>
278 <listitem><para>Print only important dependencies; for use with unmet and depends. Causes only Depends and
279 Pre-Depends relations to be printed.
280 Configuration Item:
<literal>APT::Cache::Important
</literal>.
</para></listitem>
283 <varlistentry><term><option>--no-pre-depends
</option></term>
284 <term><option>--no-depends
</option></term>
285 <term><option>--no-recommends
</option></term>
286 <term><option>--no-suggests
</option></term>
287 <term><option>--no-conflicts
</option></term>
288 <term><option>--no-breaks
</option></term>
289 <term><option>--no-replaces
</option></term>
290 <term><option>--no-enhances
</option></term>
291 <listitem><para>Per default the
<literal>depends
</literal> and
292 <literal>rdepends
</literal> print all dependencies. This can be tweaked with
293 these flags which will omit the specified dependency type.
294 Configuration Item:
<literal>APT::Cache::Show
<replaceable>DependencyType
</replaceable></literal>
295 e.g.
<literal>APT::Cache::ShowRecommends
</literal>.
</para></listitem>
297 <varlistentry><term><option>-f
</option></term><term><option>--full
</option></term>
298 <listitem><para>Print full package records when searching.
299 Configuration Item:
<literal>APT::Cache::ShowFull
</literal>.
</para></listitem>
302 <varlistentry><term><option>-a
</option></term><term><option>--all-versions
</option></term>
303 <listitem><para>Print full records for all available versions. This is the
304 default; to turn it off, use
<option>--no-all-versions
</option>.
305 If
<option>--no-all-versions
</option> is specified, only the candidate version
306 will displayed (the one which would be selected for installation).
307 This option is only applicable to the
<literal>show
</literal> command.
308 Configuration Item:
<literal>APT::Cache::AllVersions
</literal>.
</para></listitem>
311 <varlistentry><term><option>-g
</option></term><term><option>--generate
</option></term>
312 <listitem><para>Perform automatic package cache regeneration, rather than use the cache
313 as it is. This is the default; to turn it off, use
<option>--no-generate
</option>.
314 Configuration Item:
<literal>APT::Cache::Generate
</literal>.
</para></listitem>
317 <varlistentry><term><option>--names-only
</option></term><term><option>-n
</option></term>
318 <listitem><para>Only search on the package names, not the long descriptions.
319 Configuration Item:
<literal>APT::Cache::NamesOnly
</literal>.
</para></listitem>
322 <varlistentry><term><option>--all-names
</option></term>
323 <listitem><para>Make
<literal>pkgnames
</literal> print all names, including virtual packages
324 and missing dependencies.
325 Configuration Item:
<literal>APT::Cache::AllNames
</literal>.
</para></listitem>
328 <varlistentry><term><option>--recurse
</option></term>
329 <listitem><para>Make
<literal>depends
</literal> and
<literal>rdepends
</literal> recursive so
330 that all packages mentioned are printed once.
331 Configuration Item:
<literal>APT::Cache::RecurseDepends
</literal>.
</para></listitem>
334 <varlistentry><term><option>--installed
</option></term>
336 Limit the output of
<literal>depends
</literal> and
<literal>rdepends
</literal> to
337 packages which are currently installed.
338 Configuration Item:
<literal>APT::Cache::Installed
</literal>.
</para></listitem>
346 <refsect1><title>Files
</title>
353 <refsect1><title>See Also
</title>
354 <para>&apt-conf;, &sources-list;, &apt-get;
358 <refsect1><title>Diagnostics
</title>
359 <para><command>apt-cache
</command> returns zero on normal operation, decimal
100 on error.