binary?

# File lib/rdoc/parser.rb, line 72
  def self.binary?(file)
    return false if file =~ /\.(rdoc|txt)$/

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

    have_encoding = s.respond_to? :encoding

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

    if have_encoding then
      mode = "r"
      s.sub!(/\A#!.*\n/, '')     # assume shebang line isn't longer than 1024.
      encoding = s[/^\s*\#\s*(?:-\*-\s*)?(?:en)?coding:\s*([^\s;]+?)(?:-\*-|[\s;])/, 1]
      mode = "rb:#{encoding}" if encoding
      s = File.open(file, mode) {|f| f.gets(nil, 1024)}

      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