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 emplyed 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 publically 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).