--254 is end of line
--255 is end of stream
line = "back"
function dec2Bin(dec2)
	dec = tonumber(dec2)
	dec=dec*2
	local bin=""
	for i=0,7 do
		bin=bin..tostring(math.ceil(math.floor(dec/2)%2))
		dec=math.floor(dec/2)
	end
	return string.reverse(bin)
end

function bin2Dec(bin)
	return tonumber(bin, 2)
end
function toBinary(str)
	binary = ""
	for i=1, #str do
		local a = str:sub(i, i)
		if a == "\n" then
			b = dec2Bin(254)
		else
			local b = dec2Bin(string.byte(a))
			binary = binary..b
		end
	end
	return binary
end
function fromBinary(str)
	count = 0
	actualbit = ""
	text = ""
	print("Sending "..#str * 8.." bytes")
	for i=1, #str do
		count = count+1
		actualbit = actualbit..str:sub(i,i)
		if count==8 then
			if actualbit==dec2Bin(254) then
				text = text.."\n"
			else
				text = text..string.char(bin2Dec(actualbit))
				actualbit = ""
				count = 0
			end
		end
	end
	count = nil
	actualbit = nil
	return text
end
function send(filename)
	file = fs.open(filename, "r")
	local a = file.readAll()
	file.close()
	local b = toBinary(a)
	rs.setOutput(line, true)
	sleep(0)
	rs.setOutput(line, false)
	for i=1, #b do
		local c = b:sub(i, i)
		if c=="1" then
			rs.setOutput(line, true)
			sleep(0)
			rs.setOutput(line, false)
		else
			sleep(0)
		end
	end
end
function receive(filename)
	bin = ""
	actualbit = ""
	count = 0
	os.pullEvent("redstone")
	while true do
		sleep(0)
		count = count+1
		if rs.getInput(line) then
			actualbit = actualbit.."1"
		else
			actualbit = actualbit.."0"
		end
		if count==8 then
			if actualbit == dec2Bin(255) then break end
			bin = bin..actualbit
			actualbit = ""
			count = 0
		end
	end
	actualbit = nil
	count = nil
	text = fromBinary(bin)
	file = fs.open(filename, "w")
	file.write(text)
	file.close()
end
args = {...}
if #args==2 then
	if args[1]=="-send" then
		send(args[2])
	else
		receive(args[2])
	end
end