class RDoc::Parser

def self.binary?(file)
  return false if file =~ /\.(rdoc|txt)$/
  s = File.read(file, 1024) or return false
  return true if s[0, 2] == Marshal.dump('')[0, 2] or s.index("\x00")
  mode = 'r:utf-8' # default source encoding has been changed to utf-8
  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?
end