NAME

AptPkg::Config - APT configuration interface

SYNOPSIS

use AptPkg::Config;

DESCRIPTION

The AptPkg::Config module provides an interface to APT's configuration mechanism.

Provides a configuration file and command line parser for a tree-oriented configuration environment.

AptPkg::Config

The AptPkg::Config package implements the APT Configuration class.

A global instance of the libapt-pkg _config instance is provided as $AptPkg::Config::_config, and may be imported.

The following methods are implemented:

get(KEY, [DEFAULT])

Fetch the value of KEY from the configuration object, returning undef if not found (or DEFAULT if given).

If the key ends in ::, an array of values is returned in an array context, or a string containing the values seperated by spaces in a scalar context.

A trailing /f, /d, /b or /i causes file, directory, boolean or integer interpretation (the underlying XS call is FindAny).

get_file(KEY, [DEFAULT]), get_dir(KEY, [DEFAULT])

Variants of get which prepend the directory value from the parent key. The get_dir method additionally appends a `/'.

For example, given the configuration file:

    foo "/some/dir/" { bar "value"; }

then:

    $conf->get("foo::bar")	# "value"
    $conf->get_file("foo::bar")	# "/some/dir/value"
    $conf->get_dir("foo::bar")	# "/some/dir/value/"

get_bool(KEY, [DEFAULT])

Another get varient, which returns true (1) if the value contains any of:

    1 yes true with on enable

otherwise false ('').

set(KEY, VALUE)

Set configuration entry KEY to VALUE. Returns VALUE. Note that empty parent entries may be created for KEYs containing ::.

exists(KEY)

Test if KEY exists in the configuration.

dump

Principally for debugging, output the contents of the configuration object to stderr.

read_file(FILE, [AS_SECTIONAL, [DEPTH]])

Load the contents of FILE into the object. The format of the file is described in apt.conf(5).

If the AS_SECTIONAL argument is true, then the file is parsed as a BIND-style config. That is:

    foo "bar" { baz "quux"; }

is interpreted as if it were:

    foo::bar { baz "quux"; }

The DEPTH argument may be used to restrict the number of nested include directives processed.

read_dir(DIR, [AS_SECTIONAL, [DEPTH]])

Load configuration from all files in DIR.

init

Initialise the configuration object with some default values for the libapt-pkg library and reads the default configuration file /etc/apt/apt.conf (or as given by the environment variable APT_CONFIG) if it exists.

system

Return the AptPkg::System object apropriate for this system.

parse_cmdline(DEFS, [ARG, ...])

Parse the arguments given by ARGs based on the contents of DEFS and returns the list of remaining arguments.

Note, the function does not return if there are errors processing the args. Use eval to trap such errors.

DEFS is a reference to an array containing a set argument definition arrays. The elements of each definition define: the short argument character, the long argument string, the configuration key and the optional argument type (defaults to Boolean).

Valid argument types are defined by the strings:

    HasArg	takes an argument value (-f foo)
    IntLevel	defines an integer value (-q -q, -qq, -q2, -q=2)
    Boolean	true/false (-d, -d=true, -d=yes, --no-d, -d=false, etc)
    InvBoolean	same as Boolean but false with no specified sense (-d)
    ConfigFile	load the specified configuration file
    ArbItem	arbitary configuration string of the form key=value

The configuration key in the last two cases is ignored, and for the rest gives the key into which the value is placed.

Single case equivalents also work (has_arg == HasArg).

Example:

    @files = $conf->parse_cmndline([
	    [ 'h', 'help', 'help' ],
	    [ 'v', 'version', 'version' ],
	    [ 'c', 'config-file', '', ConfigFile ],
	    [ 'o', 'option', '', ArbItem ],
	], @ARGV);

The module uses AptPkg::hash to provide a hash-like access to the object, so that $conf->{key} is equivalent to using the get/set methods.

Additionally inherits the constructor (new) and keys methods from that module.

Methods of the internal XS object (AptPkg::_config) such as Find may also be used. See AptPkg.

AptPkg::Config::Iter

Iterator object for AptPkg::Config which is returned by the keys method.

new(XS_OBJ, [ROOT]): Constructor, which is invoked by the keys method. ROOT, if given determines the subset of the tree to walk (may be given as an argument to keys).
next: Returns the current key and advances to the next.

AUTHOR