AptPkg::Cache(3)

NAME
AptPkg::Cache - APT package cache interface

SYNOPSIS
use AptPkg::Cache;

DESCRIPTION
The AptPkg::Cache module provides an interface to APT's package cache.

  AptPkg::Cache
The AptPkg::Cache package implements the APT pkgCacheFile class as a hash reference (inherits from AptPkg::hash). The hash keys are the names of packages in the cache, and the values are AptPkg::Cache::Package objects (which in turn appear as hash references, see below).

Constructor

new([LOCK])
    Instantiation of the object uses configuration from the $AptPkg::Config::_config and $AptPkg::System::_system objects (automatically initialised if not done explicitly).

    The cache initialisation can be quite verbose--controlled by the value of $_config->{quiet}, which is set to "2" (quiet) if the $_config object is auto-initialised.

    The cache directory is locked if LOCK is true.

    It is important to note that the structure of the returned object contains self-referential elements, so some care must be taken if attempting to traverse it recursively.

Methods

files
    Return a list of AptPkg::Cache::PkgFile objects describing the package files.

packages
    Return an AptPkg::PkgRecords object which may be used to retrieve additional information about packages.

get, exists, keys
    These methods are used to implement the hashref abstraction: $obj->get($pack) and $obj->{$pack} are equivalent.

is_multi_arch
    Cache is multi-arch enabled.

native_arch
    Native architecture.

  AptPkg::Cache::Package
Implements the APT pkgCache::PkgIterator class as a hash reference.

Keys

Name
Section
Arch
    Package name, section and architecture.

FullName
    Fully qualified name, including architecture.

ShortName
    The shortest unambiguous package name: the same as "Name" for native packages, and "FullName" for non-native.

SelectedState
InstState
CurrentState
    Package state from the status file.

    SelectedState may be "Unknown", "Install", "Hold", "DeInstall" or "Purge".

    InstState may be "Ok", "ReInstReq", "HoldInst" or "HoldReInstReq".

    CurrentState may be "NotInstalled", "UnPacked", "HalfConfigured", "HalfInstalled", "ConfigFiles" or "Installed".

    In a numeric context, SelectedState, InstState and CurrentState evaluate to an AptPkg::State:: constant.

VersionList
    A reference to an array of AptPkg::Cache::Version objects describing available versions of the package.

CurrentVer
    An AptPkg::Cache::Version object describing the currently installed version (if any) of the package.

RevDependsList
    A reference to an array of AptPkg::Cache::Depends objects describing packages which depend upon the current package.

ProvidesList
    For virtual packages, this is a reference to an array of AptPkg::Cache::Provides objects describing packages which provide the current package.

Flags
    A comma separated list if flags: "Auto", "Essential" or "Important".

    In a numeric context, evaluates to a combination of AptPkg::Flag:: constants.

    [Note: the only one of these you need worry about is "Essential", which is set based on the package's header of the same name. "Auto" seems to be used internally by APT, and "Important" seems to only be set on the apt package.]

Index
    Internal APT unique reference for the package record.

  AptPkg::Cache::Version
Implements the APT pkgCache::VerIterator class as a hash reference.

Keys

VerStr
Section
Arch
    The package version, section and architecture.

MultiArch
    Multi-arch state: "No", "All", "Foreign", "Same", "Allowed", "AllForeign" or "AllAllowed".

    In a numeric context, evaluates to an AptPkg::Version:: constant.

ParentPkg
    An AptPkg::Cache::Package objct describing the package providing this version.

DescriptionList
    A list of AptCache::Cache::Description objects describing the files which descrie a package version. The list includes both Package files and Translation files, which contain translated Description fields.

TranslatedDescription
    An AptCache::Cache::Description object for the current locale, which will generally be a Translation file.

DependsList
    A reference to an array of AptPkg::Cache::Depends objects describing packages which the current package depends upon.

ProvidesList
    A reference to an array of AptPkg::Cache::Provides objects describing virtual packages provided by this version.

FileList
    A reference to an array of AptPkg::Cache::VerFile objects describing the packages files which include the current version.

Size
    The .deb file size, in bytes.

InstalledSize
    The disk space used when installed, in bytes.

Index
    Internal APT unique reference for the version record.

Priority
    Package priority: "important", "required", "standard", "optional" or "extra".

    In a numeric context, evaluates to an AptPkg::VerPriority:: constant.

  AptPkg::Cache::Depends
Implements the APT pkgCache::DepIterator class as a hash reference.

Keys

DepType
    Type of dependency: "Depends", "PreDepends", "Suggests", "Recommends", "Conflicts", "Replaces" or "Obsoletes".

    In a numeric context, evaluates to an AptPkg::Dep:: constant.

ParentPkg
ParentVer
    AptPkg::Cache::Package and AptPkg::Cache::Version objects describing the package declaring the dependency.

TargetPkg
    AptPkg::Cache::Package object describing the depended package.

TargetVer
    For versioned dependencies, TargetVer is a string giving the version of the target package required.

CompType
CompTypeDeb
    CompType gives a normalised comparison operator (>, >=, etc) describing the relationship to TargetVer ("" if none).

    CompTypeDeb returns Debian-style operators (>> rather than >).

    In a numeric context, both CompType and CompTypeDeb evaluate to an AptPkg::Dep:: constant.

    Alternative dependencies (Depends: a | b) are identified by all but the last having the AptPkg::Dep::Or bit set in the numeric representation of CompType (and CompTypeDeb).

Index
    Internal APT unique reference for the dependency record.

  AptPkg::Cache::Provides
Implements the APT pkgCache::PrvIterator class as a hash reference.

Keys

Name
    Name of virtual package.

OwnerPkg
OwnerVer
    AptPkg::Cache::Package and AptPkg::Cache::Version objects describing the providing package.

ProvideVersion
    Version of the virtual package. [Not currently supported by dpkg]

Index
    Internal APT unique reference for the provides record.

  AptPkg::Cache::VerFile
Implements the APT pkgCache::VerFileIterator class as a hash reference.

Keys

File
    An AptPkg::Cache::PkgFile object describing the packages file.

Offset
Size
    The byte offset and length of the entry in the file.

Index
    Internal APT unique reference for the version file record.

  AptPkg::Cache::PkgFile
Implements the APT pkgCache::PkgFileIterator class as a hash reference.

Keys

FileName
    Packages file path.

IndexType
    File type: "Debian Package Index", "Debian dpkg status file".

Archive
Component
Version
Origin
Label
Site
    Fields from the Release file.

Index
    Internal APT unique reference for the package file record.

  AptPkg::Cache::DescFile
Implements the APT pkgCache::DescFileIterator class as a hash reference.

Keys

File
    An AptPkg::Cache::PkgFile object describing the packages file.

SEE ALSO
AptPkg::Config(3pm), AptPkg::System(3pm), AptPkg(3pm), AptPkg::hash(3pm), AptPkg::PkgRecords(3pm), AptPkg::Policy(3pm).

AUTHOR
Brendan O'Dea <bod@debian.org>