def validate
      if options[:config].nil?
        unless (File.exist?("config.yaml"))
          Trollop::die "No config file in default location (#{Dir.pwd}). You
                        need to specify the #{:config} parameter. Read the
                        documentation on how to create a config.yaml file."
        end
      else
        Trollop::die "Cannot find file #{options[:config]}" \
          unless File.exist?(options[:config])
      end

      unless @options[:user].nil?
        if not Process.uid == 0
          Trollop::die "Option --user (-u) can only be specified by root"
        end
          begin
            Etc.getpwnam(@options[:user])
          rescue ArgumentError
            Trollop::die "No such user: #{@options[:user]}"
          end
      end
    end
def validate
      if options[:config].nil?
        unless (File.exist?("config.yaml"))
          Trollop::die "No config file in default location (#{Dir.pwd}). You
                        need to specify the #{:config} parameter. Read the
                        documentation on how to create a config.yaml file."
        end
      else
        Trollop::die "Cannot find file #{options[:config]}" \
          unless File.exist?(options[:config])
      end

      unless @options[:user].nil?
        if not Process.uid == 0
          Trollop::die "Option --user (-u) can only be specified by root"
        end
          begin
            Etc.getpwnam(@options[:user])
          rescue ArgumentError
            Trollop::die "No such user: #{@options[:user]}"
          end
      end
    end
Examine the validity of the provided options in the context of the
 executed command. Subclasses can also call super to also invoke the checks
 provided by this class.