# 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
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
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)
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:
Specifies the name of the module to configure (required).
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
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.
Prints a help message, including a few examples, and exits.
Ken Williams, email@example.com
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.
perl v5.22.1 2016-02-02 CONFIG_DATA(1p)
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