An improved Perl API for cme and Config::Model

Hello

While hacking on a script to update build dependencies on a Debian package, it occured to me that using Config::Model in a Perl program should be no more complicated than using cme from a shell script. That was an itch that I scratched immediately.

Fast forward a few days, Config::Model now features new cme() and modify() functions that have a behavior similar to cme modify command.

For instance, the following program is enough to update popcon’s configuration file:

use strict; # let's not forget best practices ;-)
use warnings;
use Config::Model qw(cme); # cme function must be imported
cme('popcon')->modify("PARTICIPATE=yes");

The object returned by cme() is a Config;:Model::Instance. All its methods are available for a finer control. For instance:

my $instance = cme('popcon');
$instance->load("PARTICIPATE=yes");
$instance->apply_fixes;
$instance->say_changes; 
$instance->save;

When run as root, the script above shows:

Changes applied to popcon configuration:
- PARTICIPATE: 'no' -> 'yes'

If need be, you can also retrieve the root node of the configuration tree to use Config;:Model::Node methods:

my $root_node = cme('popcon')->config_root;
say "is popcon active ? ",$root_node->fetch_element_value('PARTICIPATE');

In summary, using cme in a Perl program is now as easy as using cme from a shell script.

To provide feedback, comments, ideas, patches or to report problems, please follow the instructions from CONTRIBUTING page on github.

All the best