check a crc file matches a datafile

gistfile1.rb

      def check_crc(crc_file, datafile)
        expected_crc = File.read(crc_file).split(' ')
        actual_crc = `cksum #{datafile}`.split(' ')
        unless File.exist?(crc_file)
          puts 'crc file missing'
          return false
        end
        unless File.exist?(datafile)
          puts 'datafile missing'
          return false
        end
        unless expected_crc[1] == actual_crc[1]
          puts 'filesize mismatch'
          return false
        end
        unless expected_crc[0] == actual_crc[0]
          puts 'checksum mismatch'
          return false
        end
        return true
      end