CONFIG_DATA(1)						 Perl Programmers Reference Guide					    CONFIG_DATA(1)

NAME

       config_data - Query or change configuration of Perl modules

SYNOPSIS

	 # Get config/feature values
	 config_data --module Foo::Bar --feature bazzable
	 config_data --module Foo::Bar --config magic_number

	 # Set config/feature values
	 config_data --module Foo::Bar --set_feature bazzable=1
	 config_data --module Foo::Bar --set_config magic_number=42

	 # Print a usage message
	 config_data --help

DESCRIPTION

       The "config_data" tool provides a command-line interface to the configuration of Perl modules.  By "configuration", we mean something akin
       to "user preferences" or "local settings".  This is a formalization and abstraction of the systems that people like Andreas Koenig
       ("CPAN::Config"), Jon Swartz ("HTML::Mason::Config"), Andy Wardley ("Template::Config"), and Larry Wall (perl's own Config.pm) have
       developed independently.

       The configuration system employed here was developed in the context of "Module::Build".	Under this system, configuration information for a
       module "Foo", for example, is stored in a module called "Foo::ConfigData") (I would have called it "Foo::Config", but that was taken by all
       those other systems mentioned in the previous paragraph...).  These "...::ConfigData" modules contain the configuration data, as well as
       publicly accessible methods for querying and setting (yes, actually re-writing) the configuration data.	The "config_data" script (whose
       docs you are currently reading) is merely a front-end for those methods.  If you wish, you may create alternate front-ends.

       The two types of data that may be stored are called "config" values and "feature" values.  A "config" value may be any perl scalar,
       including references to complex data structures.  It must, however, be serializable using "Data::Dumper".  A "feature" is a boolean (1 or
       0) value.

USAGE

       This script functions as a basic getter/setter wrapper around the configuration of a single module.  On the command line, specify which
       module's configuration you're interested in, and pass options to get or set "config" or "feature" values.  The following options are
       supported:

       module
	   Specifies the name of the module to configure (required).

       feature
	   When passed the name of a "feature", shows its value.  The value will be 1 if the feature is enabled, 0 if the feature is not enabled,
	   or empty if the feature is unknown.	When no feature name is supplied, the names and values of all known features will be shown.

       config
	   When passed the name of a "config" entry, shows its value.  The value will be displayed using "Data::Dumper" (or similar) as perl code.
	   When no config name is supplied, the names and values of all known config entries will be shown.

       set_feature
	   Sets the given "feature" to the given boolean value.  Specify the value as either 1 or 0.

       set_config
	   Sets the given "config" entry to the given value.

       eval
	   If the "--eval" option is used, the values in "set_config" will be evaluated as perl code before being stored.  This allows moderately
	   complicated data structures to be stored.  For really complicated structures, you probably shouldn't use this command-line interface,
	   just use the Perl API instead.

       help
	   Prints a help message, including a few examples, and exits.

AUTHOR

       Ken Williams, kwilliams@cpan.org

COPYRIGHT

       Copyright (c) 1999, Ken Williams.  All rights reserved.

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

       Module::Build(3), perl(1).

perl v5.18.2							    2018-08-17							    CONFIG_DATA(1)