#!/usr/bin/perl -w

use strict;

my @ten_factors = (['zilch', 'one', 'two', 'three', 'four', 'five', 's
+ix', 
            'seven', 'eight', 'nine'],
           ['ten', 'eleven', 'twelve', 'thirteen', 'fourteen', 
            'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen',
            'twenty', 'thirty', 'forty', 'fifty', 'sixty', 'seventy', 
            'eighty', 'ninety'],
           'thousand',
           'million',
           'billion',
           'trillion',
           'quadrillion',
           'quintillion',
           'sextillion',
           'septillion',
           'octillion');

sub num2word
{
    my $num = shift;;
    chomp($num);
    
    die "NaN\," if($num !~ /^[0-9]*$/);

    $num = '0' . $num while(length($num) % 3);
    
    my $factor = 0;
    my $output = '';
    
    while($num)
    {
    my @trip = reverse (chop($num), chop($num), chop($num));
    my $trip = trip_convert(\@trip);
    if($factor > 0)
    {
        $trip .= ' ' . $ten_factors[$factor+1];
    }
    $output = $trip . ' ' . $output;
    $factor++;
    }
    $output =~ s/zilch [a-z]*//g;
    return $output;
}

sub trip_convert
{
    my $trip = shift;

    my $retval = '';
    if($$trip[1] == 1)
    {
    $retval = $ten_factors[1][$$trip[2]];
    }
    else
    {
    $retval = $ten_factors[0][$$trip[2]];
    $retval = $ten_factors[1][$$trip[1]+8] . ' ' . $retval unless($$tr
+ip[1] == 0);
    }
    $retval = $ten_factors[0][$$trip[0]] . ' hundred ' . $retval;
    return $retval;
}
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It isn't exactly the best I've ever written, but it works (more or less).

~Cybercosis

nemo accipere quod non merere