NAME

Data::Fallback::ConfFile - conf file package for Data::Fallback

DESCRIPTION

Data::Fallback looks through an array ref of hash refs, where each hash ref (a level) describes how to get data from that level. Here's a typical level

{ # refers to Data::Fallback::ConfFile package => 'ConfFile',

  # content is a filename, $primary_key gets parsed in with the primary key for a given request
  content => '/tmp/fallback/state_$primary_key',

  # this says the conf file will be updated with information from subsequent levels
  accept_update => 'group',

  # this would say to only allow updates of individual items
  #accept_update => 'item',
},

Please refer to the Data::Fallback perldoc for more information about lists and levels.

EXAMPLE

Let's say you have a list of directories that contain parallel conf files, like so

  # the 12 is some arbitrary primary key
  /tmp/dir1/file_12
  key1 key1 from dir1
  key2 key2 from dir1

  /tmp/dir2/file_12
  key2 key2 from dir2
  key3 key3 from dir2

The code below could be used to fallback through them.

#!/usr/bin/perl -w

use strict; use Data::Fallback;

my $self = Data::Fallback->new({

list => [ { # filename content => '/tmp/dir1/file_$primary_key', }, { content => '/tmp/dir2/file_$primary_key', }, ],

  # the package looks first to the level, then to the object
  # so if each level has the same package, you can just specify it in the object
  package => 'ConfFile',

  # lists must be names
  list_name => 'test_list',
});

# 12 is the primary key (use // if no primary key), and key3 is the name of the key to retrieve my $got = $self->get("/12/key3");

FILE PARSING

Right now, I just do something like

split /\s+/, $line, 2

to get a key/value pair for each line in the conf file. This is done through the method contentToHash, which you can easily override for more complicated parsing. The actual line looks like something like this

my %hash = $line =~ /(.+?)\s+(.+)/g;

AUTHOR

Copyright 2001-2002, Earl J. Cahill. All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

Address bug reports and comments to: cpan@spack.net.

When sending bug reports, please provide the version of Data::Fallback, the version of Perl, and the name and version of the operating system you are using.