binary?

# File lib/rdoc/parser.rb, line 76
  def self.binary?(file)
    return false if file =~ /\.(rdoc|txt)$/

    s = File.read(file, 1024) or return false

    have_encoding = s.respond_to? :encoding

    if have_encoding then
      return false if s.encoding != Encoding::ASCII_8BIT and s.valid_encoding?
    end

    return true if s[0, 2] == Marshal.dump('')[0, 2] or s.index("\x00")

    if have_encoding then
      s.force_encoding Encoding.default_external

      not s.valid_encoding?
    else
      if 0.respond_to? :fdiv then
        s.count("\x00-\x7F", "^ -~\t\r\n").fdiv(s.size) > 0.3
      else # HACK 1.8.6
        (s.count("\x00-\x7F", "^ -~\t\r\n").to_f / s.size) > 0.3
      end
    end
  end