module FileInputMixin
  def fgetb
    x=0
    ret=0
    each_byte do |i|
      ret=i || 0
      break
    end
    return ret
  end

  def fgetw
    x=0
    ret=0
    each_byte do |i|
      break if !i
      ret|=(i<<x)
      x+=8
      break if x==16
    end
    return ret
  end

  def fgetdw
    x=0
    ret=0
    each_byte do |i|
      break if !i
      ret|=(i<<x)
      x+=8
      break if x==32
    end
    return ret
  end

  def fgetsb
    ret=fgetb
    if (ret&0x80)!=0
      return ret-256
    else
      return ret
    end
  end

  def xfgetb(offset)
    self.pos=offset
    return fgetb
  end

  def xfgetw(offset)
    self.pos=offset
    return fgetw
  end

  def xfgetdw(offset)
    self.pos=offset
    return fgetdw
  end

  def getOffset(index)
    self.binmode
    self.pos=0
    offset=fgetdw>>3
    return 0 if index>=offset
    self.pos=index*8
    return fgetdw
  end

  def getLength(index)
    self.binmode
    self.pos=0
    offset=fgetdw>>3
    return 0 if index>=offset
    self.pos=index*8+4
    return fgetdw
  end

  def readName(index)
    self.binmode
    self.pos=0
    offset=fgetdw>>3
    return "" if index>=offset
    self.pos=index<<3
    offset=fgetdw
    length=fgetdw
    return "" if length==0
    self.pos=offset
    return read(length)
  end
end



module FileOutputMixin
  def fputb(b)
    b=b&0xFF
    write(b.chr)
  end

  def fputw(w)
    2.times do
      b=w&0xFF
      write(b.chr)
      w>>=8
    end
  end

  def fputdw(w)
    4.times do
      b=w&0xFF
      write(b.chr)
      w>>=8
    end
  end
end



class File < IO
=begin
  unless defined?(debugopen)
    class << self
      alias debugopen open
    end
  end

  def open(f,m="r")
    debugopen("debug.txt","ab") { |file| file.write([f,m,Time.now.to_f].inspect+"\r\n") }
    if block_given?
      debugopen(f,m) { |file| yield file }
    else
      return debugopen(f,m)
    end
  end
=end
  include FileInputMixin
  include FileOutputMixin
end



class StringInput
  include FileInputMixin

  def pos=(value)
    seek(value)
  end

  def each_byte
    while !eof?
      yield getc
    end
  end

  def binmode
  end
end



class StringOutput
  include FileOutputMixin
end