#!/usr/bin/perl
# http://search.cpan.org/~gerhard/BibTeX-Parser-0.62/lib/BibTeX/Parser.pm
use BibTeX::Parser;
use IO::File;
use Data::Dumper;
use strict;
use warnings;

my $filename="bibliography.bib";
my (%bibliography, %article);
my $i;
my ($entry, @entries, $type, $key);
my (my $hkey, my $hvalue);

# open BibTeX
my $fh = IO::File->new("$filename") or die "could not open $filename: $!\n";

# create parser object ...
my $parser = BibTeX::Parser->new($fh);
    
# ... and iterate over entries
while ($entry = $parser->next ) {
  if ($entry->parse_ok) {
  
    # return BibTeX elements like abstract, author, title ...
    @entries = $entry->fieldlist();
    
    # create %article as a hash array e.g. year -> 1996; isbn -> 1581138709 etc.
    foreach (@entries) {
      $article{"$_"} = $entry->field("$_");
    }
    
    # return article's key (Lee2000a, Forrest1996)
    $key = $entry->key;
    
    # append %article into %bibliography with approporiate key
    $bibliography{"$key"} = \%article;
    
    #Debug
    #print $entry->key, "\n";
    #print Dumper (\%article);

    # removes all elements of %article (prepare for next iteration)
    %article = ();
    
    #Debug
    #print "================================\n";
  }
  
  else {
    warn "Error parsing file: " . $entry->error;
 }
}

    #Debug
    #print Dumper (\%bibliography);