def option_excess
      ARGV.each do |opt|
	o = getopt( opt )
	if o[:n] != '' then
	  puts "fatal error: unknown option '#{o[:t]}#{o[:n]}'"
	  exit
	end
      end
    end
def option_excess
      ARGV.each do |opt|
	o = getopt( opt )
	if o[:n] != '' then
	  puts "fatal error: unknown option '#{o[:t]}#{o[:n]}'"
	  exit
	end
      end
    end
Check ARGV to exess options.