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 separated 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 appropriate 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     arbitrary 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.

SEE ALSO

       AptPkg::System(3pm), AptPkg(3pm), AptPkg::hash(3pm).

AUTHOR

       Brendan O'Dea <bod@debian.org>