neversaint,
This is really simple when you leverage the power of CPAN. 
#!/usr/bin/perl
use strict;
use warnings;
use Algorithm::Loops 'NestedLoops';
use Text::Levenshtein 'fastdistance';

my $seed = $ARGV[0] || '000';
my $iter = NestedLoops([([0..3]) x length($seed)]);

while (my @list = $iter->()) {
    my $neighbor = join '', @list;
    print "$neighbor\n" if fastdistance($neighbor, $seed) < 3;
}

[download]

Update: Explanation of how the code works: Simply counts in base 4 and checks each number to see if edit distance is less than 3 from seed.

Cheers - L~R

In reply to Re: Finding String's Neighbors By Up To 2 Differing Positions by Limbic~Region
in thread Finding String's Neighbors By Up To 2 Differing Positions by neversaint

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