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

AptPkg::Cache::Package

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

Keys

Name
Section
Package name and section.
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 seperated 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.
ParentPkg
An AptPkg::Cache::Package objct describing the package providing this version.
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.
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.
Architecture
Architecture.
Archive
Component
Version
Origin
Label
Site
Fields from the Release file.
IsOk
True if the cache is in sync with this file.
Index
Internal APT unique reference for the package file record.

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>