startup

fuel = turtle.getFuelLevel()
ID = os.getComputerLabel()


function commas (num)
  assert (type (num) == "number" or
          type (num) == "string")

  local result = ""

  -- split number into 3 parts, eg. -1234.545e22
  -- sign = + or -
  -- before = 1234
  -- after = .545e22

  local sign, before, after =
    string.match (tostring (num), "^([%+%-]?)(%d*)(%.?.*)$")

  -- pull out batches of 3 digits from the end, put a comma before them

  while string.len (before) > 3 do
    result = "," .. string.sub (before, -3, -1) .. result
    before = string.sub (before, 1, -4)  -- remove last 3 digits
  end -- while

  -- we want the original sign, any left-over digits, the comma part,
  -- and the stuff after the decimal point, if any
  return sign .. before .. result .. after

end -- function commas

print("ID:  "..ID)
print("Fuel: "..commas(fuel))