apt-cache

Query the APT package cache

TLDR

Search package names and descriptions

$ apt-cache search [keyword]

Restrict the search to names only

$ apt-cache search --names-only [keyword]

Show a package's record

$ apt-cache show [package]

Show which versions are available and which is installed

$ apt-cache policy [package]

Show the versions each repository offers

$ apt-cache madison [package]

Show what a package depends on

$ apt-cache depends [package]

Show only the hard dependencies, skipping suggests and recommends

$ apt-cache depends --important [package]

Show what depends on a package

$ apt-cache rdepends [package]

Limit reverse dependencies to installed packages

$ apt-cache rdepends --installed [package]

Show the raw record, including providers and reverse dependencies

$ apt-cache showpkg [package]

List every package name starting with a prefix

$ apt-cache pkgnames [prefix]

Report unmet dependencies in the cache

$ apt-cache unmet

Summarize the cache itself

$ apt-cache stats

SYNOPSIS

apt-cache [options] command [arguments]

apt-cache queries the local APT package cache to search for packages, display detailed package information, and analyze dependency relationships. It reads the package index files downloaded by apt update and provides fast, offline access to package metadata without contacting remote repositories.Common operations include searching for packages by name or description, inspecting version and dependency details, checking installation policies, and listing reverse dependencies. The output is suitable for scripting and can help diagnose dependency conflicts or determine which repository provides a given package.

PARAMETERS

search regex

Search for packages matching the POSIX regex in names and descriptions

show package

Show detailed package record for a package

showpkg package

Show general information including versions and dependencies

showsrc package

Show all source package records for a package

policy [package]

Show policy settings, installation status, and repository priorities

depends package

Show dependencies for a package

rdepends package

Show reverse dependencies (packages that depend on this one)

madison package

Show available versions in a tabular format

pkgnames [prefix]

List all package names in the cache, optionally filtered by prefix

stats

Show cache statistics

dump

Show a short listing of every package in the cache

unmet

Show a summary of all unmet dependencies in the cache

-f, --full

Print full package records when searching

-n, --names-only

Only search package names, not descriptions

-i, --important

Print only Depends and Pre-Depends relations (for use with depends and unmet)

--installed

Limit output to currently installed packages

--recurse

Make depends and rdepends recursive

CONFIGURATION

/etc/apt/sources.list

Main file listing configured package repositories.

/etc/apt/sources.list.d/

Directory for additional repository source files.

/etc/apt/preferences.d/

Directory for package pinning and priority preferences.

INSTALL

sudo apt install apt

sudo dnf install apt

sudo pacman -S apt

sudo apk add apt

brew install apt

nix profile install nixpkgs#apt

CAVEATS

This tool operates on the local cache; run apt update first to ensure the cache is current.

HISTORY

Part of the APT (Advanced Package Tool) suite developed for Debian-based systems in the late 1990s.