use strict;
use DB_File;

# Hash with composite key strings: $words{category-word} gives count of
# 'word' in 'category'.  Tied to a DB_File to keep it persistent.

my %words;
tie %words, 'DB_File', 'words.db';

open( TXT, '>', 'words.txt';

while ( my ($key, $value) = each %words ) {
    print TXT "$key\t$value\n";
}
close TXT;
untie %words;