Reads Bind zone files

gistfile1.rb

#!/usr/bin/ruby

def resolve_node(node)
  return node if node[-1] == '.'[0]
  return node unless $context.has_key? "ORIGIN"
  return "#{node}.#{$context["ORIGIN"]}"
end

ARGS.each do |filename|
  File.open filename, 'r' do |file|
    $context = {}

    file.each_line do |line|
      if line.match /^\$([A-Z]+)\s+(.*)/ then
        key, value = $1.strip, $2.sub(/\s*;.*$/, '').strip
        $context[key] = value
      elsif line.match /(\S+)\s+(A|CNAME)\s+(\S+)/ then
        node = resolve_node $1.strip
        type = $2.strip
        pointer = $3.sub(/\s*;.*$/, '').strip
        action = case type
                 when "A" then
                   "is homed at"
                 when "CNAME" then
                   pointer = resolve_node pointer
                   "is an alias for"
                 else
                   nil
        end
        unless action.nil?
          puts "#{node} #{action} #{pointer}"
        end
      end
    end
  end
end