# config_data(1p) - man - phpMan

[CONFIG_DATA(1p)](https://www.chedong.com/phpMan.php/man/CONFIGDATA/1p/markdown)                  User Contributed Perl Documentation                 [CONFIG_DATA(1p)](https://www.chedong.com/phpMan.php/man/CONFIGDATA/1p/markdown)



## NAME
       config_data - Query or change configuration of Perl modules

## SYNOPSIS
         # Get config/feature values
         config_data --module [Foo::Bar](https://www.chedong.com/phpMan.php/perldoc/Foo%3A%3ABar/markdown) --feature bazzable
         config_data --module [Foo::Bar](https://www.chedong.com/phpMan.php/perldoc/Foo%3A%3ABar/markdown) --config magic_number

         # Set config/feature values
         config_data --module [Foo::Bar](https://www.chedong.com/phpMan.php/perldoc/Foo%3A%3ABar/markdown) --set_feature bazzable=1
         config_data --module [Foo::Bar](https://www.chedong.com/phpMan.php/perldoc/Foo%3A%3ABar/markdown) --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](https://www.chedong.com/phpMan.php/perldoc/CPAN%3A%3AConfig/markdown)"), Jon Swartz ("[HTML::Mason::Config](https://www.chedong.com/phpMan.php/perldoc/HTML%3A%3AMason%3A%3AConfig/markdown)"), Andy Wardley
       ("[Template::Config](https://www.chedong.com/phpMan.php/perldoc/Template%3A%3AConfig/markdown)"), and Larry Wall (perl's own Config.pm) have developed independently.

       The configuration system employed here was developed in the context of "[Module::Build](https://www.chedong.com/phpMan.php/perldoc/Module%3A%3ABuild/markdown)".
       Under this system, configuration information for a module "Foo", for example, is stored in a
       module called "[Foo::ConfigData](https://www.chedong.com/phpMan.php/perldoc/Foo%3A%3AConfigData/markdown)") (I would have called it "[Foo::Config](https://www.chedong.com/phpMan.php/perldoc/Foo%3A%3AConfig/markdown)", 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](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3ADumper/markdown)".  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](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3ADumper/markdown)" (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)](https://www.chedong.com/phpMan.php/man/Build/3/markdown), [**perl**(1)](https://www.chedong.com/phpMan.php/man/perl/1/markdown).



perl v5.30.0                                 2020-01-30                              [CONFIG_DATA(1p)](https://www.chedong.com/phpMan.php/man/CONFIGDATA/1p/markdown)