config_data - Query or change configuration of Perl modules
- # 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
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.
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 shown.
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.
Sets the given feature
to the given boolean value. Specify the value
as either 1 or 0.
Sets the given config
entry to the given value.
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, kwilliams@cpan.org
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.
Module::Build(3), perl(1).