sub process_article {
my $fh=shift; # Filehandle
my $locations=shift; # Reference to hash containing location information for this article
my $keywords=shift; # Reference to an array containing keywords
my $all=shift; # Reference to a list of all keywords or chromosomal bands found

if (-e "$$locations{file}") { # If file exists in the location indicated by the index file
    open(INFO, "$$locations{file}") or die("cannot open file $$locations{file}: $!");
    } else { # If not, search for it
    my ($file)=($$locations{file}=~/.+\/(.+)/); # Get just the filename
    find(sub{m/$file/ and $file=$File::Find::name}, 'c:/perl' );
    open(INFO, "$file") or die("cannot open file $file: $!");
    }
seek (INFO, $$locations{offset}, 0); # Set location to article
my $string=<INFO>; # Get line from file
my ($title, $line, $abstract)=($string=~/(.+?)\t(.+)\t(.*)/);
if (@$keywords) { # If keywords were provided
    my ($score, @found)=find_keywords($title.' '.$abstract, @$keywords); # Get keywords
    push @$all, @found;
    my $kwords_found=join('|', @found);
    print $fh "$title\t$line\t$kwords_found\t$score\n" if ($score>0); # Print line
    } else { # No keywords provided, means look for chromosomal bands
    my ($score, @found)=find_bands($title.' '.$abstract); # Get chromosomes
    push @$all, @found;
    my $chroms_found=join('|', @found);
    print $fh "$title\t$line\t$chroms_found\t$score\n" if ($score>0); # Print line
    }
close(INFO);
}