module Utils::FileXt

def binary?
  old_pos = tell
  seek 0, SEEK_SET
  data = read 2 ** 13
  !data or data.empty? and return nil
  data.count(ZERO) > 0 and return true
  data.count(BINARY).to_f / data.size > 0.3
ensure
  seek old_pos, SEEK_SET
end