I felt a bit limited by this, so I've just knocked up a similar tool with far more flexibility. Still actively developing it, but it's far quicker already.
http://dev.mindfuzz.net/domain/
Edit: Grammar.
http://dev.mindfuzz.net/domain/
Edit: Grammar.
do you produce the string with the monte carlo choosing within a specific subset? I'm not sure why it wouldn't produce more than 5 combinations and then 5 different combinations...
also, if you have-time/like, you can probably implement a quick hash on the fly for the domains already returned to avoid listing the same domain twice in a search with few alternatives, it should be quick.
but cool tool!
I build an array of arrays where each subset array has all the possibilities for that letter. So if the query was N then a[0] = [0,..,9]. Then I just pick a random element from each subset array and stitch them all together in order.
Checking if a domain name is registered can be a trick task. The only reliable method is to run a whois; but most hosts only search a fraction of the whois records (perhaps just .com) and also limit your queries. You need to pay money to make mass requests.
I have opted to check for any kind of DNS record. That means registered but unused domains will still return available, but the trade off is that it's very quick, pretty accurate most of the time and most importantly free. :)
the page is pretty, results are fast, and the letter based slots specification is nice.
but i think the results are pretty low quality (gibberish).
Warner Brothers appear to have registered batman[1-9].com, heh.