Here is a little something allowing you to enter the number of ABC colums and to specify min and max values (ie 0 and 1, 0 and 9, a and z)

#!/usr/local/bin/perl -w
use strict;

print "enter number of columns:";
chomp (my $ow_many=<>);
my $min="f";
my $max="h";
my @array;

$array[$_-1]=$min for 1..$ow_many;

my $i=0;
while ($i <= $ow_many) {
    my $x="";
    for (@array) {$x=$_ if $_ gt $x}
    print join " ", @array, " $x\n";
    $i=0;
    my $carry=1;
    while ($carry) {
        if (defined $array[$i] && $array[$i] eq $max) {
            $array[$i]=$min;
        }else{
           $carry--;
           $array[$i]++;
        }
        $i++;
    }
}
[download]

Cheers,
R.