String to Binary

local function numberString(number)
  local s = ""
  repeat
    local remainder = number % 2
    s = remainder..s
    number = (number-remainder)/2
  until number==0
  return s
end
function fromBinary(str)
  if #str % 8 ~= 0 then
    error("Malformed Binary Sequence",2)
  end
  local result = ""
  for i = 1, #str, 8 do
   result = result..string.char(tonumber(str:sub(i,i+7),2))
  end
  return result
end
function toBinary(str)
  if #str > 0 then
    local result = ""
    for a = 1, #str do
      result = result..string.format("%08d",numberString(string.byte(string.sub(str,a,a))))
    end
    return result
  else return nil
  end
end