rtty.scala

import java.io._

object Baudot {
  val ShiftToFigures = 0x1b
  val ShiftToLetters = 0x1f

  val figures = Map(
    0.toChar -> 0x0,
    ' '      -> 0x4,
    '1'      -> 0x1d,
    '2'      -> 0x19,
    '3'      -> 0x10,
    '4'      -> 0xa,
    '5'      -> 0x1,
    '6'      -> 0x15,
    '7'      -> 0x1c,
    '8'      -> 0xc,
    '9'      -> 0x3,
    '0'      -> 0xd,
    '-'      -> 0x18,
    7.toChar -> 0x14,
    '$'      -> 0x12,
    '!'      -> 0x16,
    '&'      -> 0xb,
    '#'      -> 0x5,
    '\''     -> 0x1a,
    '('      -> 0x1e,
    ')'      -> 0x9,
    '"'      -> 0x11,
    '/'      -> 0x17,
    ':'      -> 0xe,
    ';'      -> 0xf,
    '?'      -> 0x13,
    ','      -> 0x6,
    '.'      -> 0x7,
    '\r'     -> 0x2,
    '\n'     -> 0x8
  )

  val letters = Map(
    0.toChar -> 0x0,
    ' '      -> 0x4,
    'Q'      -> 0x1d,
    'W'      -> 0x19,
    'E'      -> 0x10,
    'R'      -> 0xa,
    'T'      -> 0x1,
    'Y'      -> 0x15,
    'U'      -> 0x1c,
    'I'      -> 0xc,
    'O'      -> 0x3,
    'P'      -> 0xd,
    'A'      -> 0x18,
    'S'      -> 0x14,
    'D'      -> 0x12,
    'F'      -> 0x16,
    'G'      -> 0xb,
    'H'      -> 0x5,
    'J''     -> 0x1a,
    'K'      -> 0x1e,
    'L'      -> 0x9,
    'Z'      -> 0x11,
    'X'      -> 0x17,
    'C'      -> 0xe,
    'V'      -> 0xf,
    'B'      -> 0x13,
    'N'      -> 0x6,
    'M'      -> 0x7,
    '\r'     -> 0x2,
    '\n'     -> 0x8
  )
}

object RTTY {
  def main(args: Array[String]) {
    val input = new File(args(0))
    val output = new File(args(1))
    require(input.exists, "The input file does not exist.")
    require(output.canWrite, "The output file must be writable.")

    val inputStream = new DataInputStream(new BufferedInputStream(new FileInputStream(input)))
    val outputStream = new FileOutputStream(output)

    try {
      Iterator
        .continually(inputStream.readChar)
        .foreach { char =>

          // ...

        }
    } catch {
      case e: Throwable => outputStream.close()
    }
  }
}