Dynamically parse BibTeX and create hash of hash

[wakatana]

Hello gurus, Iam trying to parse following BibTex file (bibliography.bib):

@book{Lee2000a,
abstract = {Abstract goes here},
author = {Lee, Wenke and Stolfo, Salvatore J},
title = {{Data mining approaches for intrusion detection}},
year = {2000}
}
@article{Forrest1996,
abstract = {Abstract goes here},
author = {Forrest, Stephanie and Hofmeyr, Steven A. and Anil, Somayaji},
title = {{Computer immunology}},
year = {1996}
}

I am using BibTeX-Parser for this which works as expected, problem that I have is with creating hash of hash array. Following code:

#!/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);

CURRENT output of Dumper (\%bibliography);

$VAR1 = {
          'Lee2000a' => {},
          'Forrest1996' => $VAR1->{'Lee2000a'}
        };

EXPECTED output of Dumper (\%bibliography);

$VAR1 = {
          'Lee2000a' => {
			    'abstract' => 'Abstract goes here',
			    'author' => 'Lee, Wenke and Stolfo, Salvatore J'
			    'title' => 'Data mining approaches for intrusion detection'
			    'year' => '2000'
			  },
          'Forrest1996' => {
			    'abstract' => 'Abstract goes here',
			    'author' => 'Forrest, Stephanie and Hofmeyr, Steven A. and Anil, Somayaji'
			    'title' => 'Computer immunology'
			    'year' => '1996'
			    }
        };

What I am doing Wrong ? Many thanks.

[atreyu]

Hi,

Try this modified loop:

while($entry = $parser->next ){
  if($entry->parse_ok){

    # return article's key (Lee2000a, Forrest1996)
    $key = $entry->key;

    # 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) {

#      $article->{"$_"} = $entry->field("$_");
      $bibliography{$key}{$_} = $entry->field($_);
    }
  }else{
    warn "error...";
  }
}