.bashrc 1-character whois. Bash function to check domain name availability; type one character, get one character.

bash_fast_whois_checker_function.sh

d () {
  # see http://troy.yort.com/short-fast-micro-whois
  result=`dig -t NS "$1" | grep -c "ANSWER SECTION"`
  if [ "$result" = "0" ]; then
    # some registered domains have no NS resource record in root servers; may 
    # be false negative, so confirm with whois
    result=`whois -n "$1" | grep -c "Registrar: "`
  fi
  echo $result
  return $result
}

bash_fast_whois_checker_ruby.sh

d () {
  # see http://troy.yort.com/short-fast-micro-whoisshort-fast-micro-whois
  # note: does not handle registered domain without NS records
  ruby -e "require 'net/dns/resolver'; available = Net::DNS::Resolver.new.send('$1', 'NS').answer.empty?; puts available ? '0' : '1'"
}