A random script I wrote to look up short potentially available domain names that are 'real' words including the TLD. This was a random script I pulled out a laptop that I was cleaning up and I'm saving for posterity.

idn.rb

#!/usr/bin/env ruby

require 'socket'

# cc.cc, cu.cc, cz.cc, co.nr, dot.tk -> Free domain services
# Pity can't do .ie, .it as they're common word endings

# This is a list of the ASCII internationalized TLDs that allow second level
# domain registrations and do not require any form of physical presence of
# citizenship within their country as reported by Wikipedia.
tld_list = %w{
  ac ae af ag ai am ao as at ax az ba bb be bf bg bh bi bj bs bw by bz cc cd cf
  cg ch ci ck cl co cr cu cv cx cy cz dj dk dm do dz ec eg es fj fm fo ga gd de
  df gg gh gi gl gm gp gr gs gt gw gy hk hm hn hr ht im in io iq ir is je jo kg
  hi hm hn kr kz la bc li lk lt lu lv ly ma md me mg mh ml mn mp mr ms mu mv mw
  mx na nc ne nf ng nl nr nu pe pf ph pk pl pn pr ps pt pw ro rs ru rw sc sd se
  sg sh si sk sl sn so sr st su sy tc tg tj tk tl tm tn to tp tr tt tv tw ug us
  uy uz vc vg vi vn vu ws
}

# The following were removed because it was found they were unable to be
# reasonably obtained or the sole provider of them added further restrictions
# (such as a minimum character length)

blacklist_tld = %w{
  li
}

tld_list = tld_list - blacklist_tld

found_domains = []

def has_a_record(domain)
  !!(Socket.getaddrinfo(domain, 0, Socket::AF_UNSPEC, Socket::SOCK_STREAM, nil, Socket::AI_CANONNAME))
rescue SocketError
  false
end

nr = File.open('name_report.txt', 'w')

File.open('/usr/share/dict/words', 'r') do |f|
  while !f.eof?
    line = f.readline.strip.downcase

    # We're looking for short domain names...
    next if line.length > 7
    # ... but is not just a TLD ...
    next unless line.length > 2
    # ... that end in a valid TLD ...
    next unless tld_list.include?(line[-2..-1])
    # ... which only include regular characters ...
    next unless line.match(/\A[a-z0-9]+\Z/i)
    # ... and isn't a duplicate of one we've already found
    next if found_domains.include?(line)

    domain = line.insert(-3, '.')

    # We also only care about domains that might not be registered
    next if has_a_record(domain)

    nr.write("#{domain}\n")
    found_domains << domain
  end
end

# Order by the length of the domain (smallest first)
found_domains = found_domains.sort_by { |t| t.size }

nr.close

# Print out the first 100
puts found_domains.first(300).inspect