numbers = {}
numbers["1"] = " "
numbers["2"] = "!"
numbers["3"] = '"'
numbers["4"] = "#"
numbers["5"] = "$"
numbers["6"] = "%"
numbers["7"] = "&"
numbers["8"] = "'"
numbers["9"] = "("
numbers["10"] = ")"
numbers["11"] = "*"
numbers["12"] = "+"
numbers["13"] = ","
numbers["14"] = "-"
numbers["15"] = "."
numbers["16"] = "/"
numbers["17"] = "0"
numbers["18"] = "1"
numbers["19"] = "2"
numbers["20"] = "3"
numbers["21"] = "4"
numbers["22"] = "5"
numbers["23"] = "6"
numbers["24"] = "7"
numbers["25"] = "8"
numbers["26"] = "9"
numbers["27"] = ":"
numbers["28"] = ";"
numbers["29"] = "<"
numbers["30"] = "="
numbers["31"] = ">"
numbers["32"] = "?"
numbers["33"] = "@"
numbers["34"] = "A"
numbers["35"] = "B"
numbers["36"] = "C"
numbers["37"] = "D"
numbers["38"] = "E"
numbers["39"] = "F"
numbers["40"] = "G"
numbers["41"] = "H"
numbers["42"] = "I"
numbers["43"] = "J"
numbers["44"] = "K"
numbers["45"] = "L"
numbers["46"] = "M"
numbers["47"] = "N"
numbers["48"] = "O"
numbers["49"] = "P"
numbers["50"] = "Q"
numbers["51"] = "R"
numbers["52"] = "S"
numbers["53"] = "T"
numbers["54"] = "U"
numbers["55"] = "V"
numbers["56"] = "W"
numbers["57"] = "X"
numbers["58"] = "Y"
numbers["59"] = "Z"
numbers["60"] = "["
numbers["61"] = "\\"
numbers["62"] = "]"
numbers["63"] = "^"
numbers["64"] = "_"
numbers["65"] = "`"
numbers["66"] = "a"
numbers["67"] = "b"
numbers["68"] = "c"
numbers["69"] = "d"
numbers["70"] = "e"
numbers["71"] = "f"
numbers["72"] = "g"
numbers["73"] = "h"
numbers["74"] = "i"
numbers["75"] = "j"
numbers["76"] = "k"
numbers["77"] = "l"
numbers["78"] = "m"
numbers["79"] = "n"
numbers["80"] = "o"
numbers["81"] = "p"
numbers["82"] = "q"
numbers["83"] = "r"
numbers["84"] = "s"
numbers["85"] = "t"
numbers["86"] = "u"
numbers["87"] = "v"
numbers["88"] = "w"
numbers["89"] = "x"
numbers["90"] = "y"
numbers["91"] = "z"
numbers["92"] = "{"
numbers["93"] = "|"
numbers["94"] = "}"
numbers["95"] = "~"
numbers["96"] = "end of line"
numbers["97"] = "ping"
function getChar(str, pos)
	return str:sub(pos, pos)
end
function numbertoBinary(dec)
	dec = tonumber(dec)
	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 numberfromBinary(bin)
  return tonumber(bin, 2)
end
function getNumber(str)
	count = 0
	for k,v in pairs(numbers) do
		count = count+1
		if v=="str" then return count end
	end
end
function toBinary(str)
	bin = ""
	for i=1, #str do
		local a = getChar(str, i)
		if a=="\n" then a = "end of line" end
		local b = getNumber(a)
		bin = bin..numbertoBinary(b)
	end
	print("Passed to binary")
	return bin
end
function fromBinary(str)
	count = 0
	temp = ""
	tempt = {}
	result = ""
	for i=1, #str do
		count = count+1
		temp = temp..str[i]
		if count==8 then
			table.insert(tempt, temp)
			temp = ""
			count = 0
		end
	end
	for i=1, #tempt do
		local a = numberfromBinary(tempt[i])
		if a=="end of line" then a = "\n" end
		result = result..temp
	end
	temp = nil
	count = nil
	tempt = nil
	return result
end
line = "back"
args = {...}
result = ""
if not args==2 then
	error(shell.getRunningProgram().." send/receive filename")
end
if args[1]=="send" then
	file = fs.open(args[2], "r")
	local rts = file.readAll()
	file.close()
	tosend = numbertoBinary(97)..toBinary(rts)..numbertoBinary(97)
	print("Sending...")
	for i=1, #tosend do
		local bit = getChar(tosend, i)
		if bit=="1" then
			rs.setOutput(line, true)
			sleep(0.2)
			rs.setOutput(line, false)
		else
			sleep(0.2)
		end
		sleep(0)
	end
	print("sended")
else
	os.pullEvent("redstone")
	actualbit = ""
	count = 0
	resultb = ""
	started = false
	while true do
		if rs.getInput(line) then
			count = count+1
			actualbit = actualbit.."1"
		else
			count = count+1
			actualbit = actualbit.."0"
		end
		sleep(0.2)
		if count==8 then
			if actualbit==numbertoBinary(97) then
				if started then break end
				if not started then started = true end
			else
				resultb = resultb..actualbit
			end
			actualbit = ""
			count = 0
		end
	end
	actualbit = nil
	count = nil
	started = nil
	result = fromBinary(resultb)
	resultb = nil
	file = fs.open(args[2], "w")
	file.write(result)
	file.close()
	result = nil
end