#! /usr/bin/env ruby

# --
# Copyright 2007 Nominet UK
# 
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ++

# = NAME
# 
# digitar - Ruby script to perform DNS queries, validated against the IANA TAR
# (trust anchor repository).
# 
# = SYNOPSIS
# 
# digroot name [ type [ class ] ]
# 
# = DESCRIPTION
# 
# Performs a DNS query on the given name.  The record type
# and class can also be specified; if left blank they default
# to A and IN. The program firstly performs the requested DNS
# query. The response is then validated from the signed root.
# 
# = AUTHOR
# 
# Michael Fuhr <mike@fuhr.org>
# Alex D <alexd@nominet.org.uk>

require 'dnsruby'

def fatal_error(message)
  puts message
  exit -1
end

unless (1..3).include?(ARGV.length)
  fatal_error("Usage: #{$0}  name [ type [ class ] ]")
end


inner_resolver = Dnsruby::Resolver.new
inner_resolver.do_validation = true
resolver = Dnsruby::Recursor.new(inner_resolver)

#    Dnsruby::TheLog.level=Logger::DEBUG

name, type, klass = ARGV
type  ||= 'A'
klass ||= 'IN'

begin
  answer = resolver.query(name, type, klass)
  print answer
rescue Exception => e
  fatal_error("query failed: #{e}")
end
