read

sign = peripheral.wrap("right")
while true do
  if turtle.detect() then
    text1,text2,text3,text4 = sign.read()
    if text1 == "Left" or text1 == "left" or text1 == "LEFT" then
      turtle.turnLeft()
      turtle.forward()
    elseif text1 == "Right" or text1 == "right" or text1 == "RIGHT" then
      turtle.turnRight()
      turtle.forward()
    elseif text1 == "Stop" or text1 == "stop" or text1 == "STOP" then
      break
    elseif text1 == "Break" or text1 == "break" or text1 == "BREAK" then
      turtle.dig()
      turtle.forward()
      turtle.dig()
      turtle.back()
      turtle.place("Stop")
    elseif text1 == "Forward" or text1 == "forward" or text1 == "FORWARD" then
      turtle.dig()
      turtle.forward()
    elseif test1 == "Back" or text1 == "back" or text1 == "BACK" then
      turtle.back()
    elseif text1 == "Up" or text1 == "up" or text1 == "UP" then
      turtle.digUp()
      turtle.up()
    elseif text1 == "Down" or text1 == "down" or text1 == "DOWN" then
      turtle.digDown()
      turtle.down()
    elseif text1 == "Dance" or text1 == "dance" or text1 == "DANCE" then
      shell.run("dance")
    elseif text1 == "Craft" or text1 == "craft" or text1 == "CRAFT" then
      turtle.craft()
    elseif text1 == "Place" or text1 == "place" or text1 == "PLACE" then
      if text2 ~= nil then
        text2 = tonumber(text2)
        turtle.select(text2)
      end
      if text3 ~= nil and text4 == nil then
        turtle.dig()
        turtle.place(text3)
      elseif text3 == nil and text4 == nil then
        turtle.dig()
        turtle.place()
      elseif text3 ~= nil and text4 ~= nil then
        if text4 == "right" or text4 == "Right" or text4 == "RIGHT" then
          turtle.turnRight()
          turtle.place(text3)
          turtle.turnLeft()
        elseif text4 == "left" or text4 == "Left" or text4 == "LEFT" then
          turtle.turnLeft()
          turtle.place(text3)
          turtle.turnRight()
        elseif text4 == "up" or text4 == "Up" or text4 == "UP" then
          turtle.placeUp(text3)
        elseif text4 == "down" or text4 == "Down" or text4 == "DOWN" then
          turtle.placeDown(text3)
        end
        turtle.dig()
      elseif text3 == nil and text4 ~= nil then
        if text4 == "right" or text4 == "Right" or text4 == "RIGHT" then
          turtle.turnRight()
          turtle.place()
          turtle.turnLeft()
        elseif text4 == "left" or text4 == "Left" or text4 == "LEFT" then
          turtle.turnLeft()
          turtle.place()
          turtle.turnRight()
        elseif text4 == "up" or text4 == "Up" or text4 == "UP" then
          turtle.placeUp()
        elseif text4 == "down" or text4 == "Down" or text4 == "DOWN" then
          turtle.placeDown()
        end
        turtle.dig()
      end
      print(text1)
    else
      error(text1.." is an unrecognised Sign Command.")
    end
  else
    error("No sign found.")
  end
end