oc netcat over modems

local shell = require("shell")
local fs = require("filesystem")
local component = require("component")
local event = require("event")

if not component.modem then
	error("wireless network card required")
end

local modem = component.modem
if not modem.isWireless() then
	error("wireless network card required")
end

local args, options = shell.parse(...)
if #args < 2 then
  error("usage: netcat [-r: receive] <port> <file [use '-' for stdin / recv end stdout]>")
end

local port = tonumber(args[1])

if not port then
	error("invalid port")
end
local file = args[2]

if options.r then
	modem.open(port)

	local input_method, input_param = "write", require("tty").getViewport()

	--for i = 1, #args do
		local arg = shell.resolve(args[2])
		if fs.isDirectory(arg) then
			io.stderr:write(string.format('netcat %s: Is a directory\n', arg))
			os.exit(1)
		else
			local file, reason
			if args[2] == "-" then
				file, reason = io.stdout, "missing stdout"
				input_method, input_param = "write", false
			else
				file, reason = fs.open(arg)
			end
			if not file then
				io.stderr:write(string.format("netcat: %s: %s\n", args[i], tostring(reason)))
				os.exit(1)
			else
				while true do
					local _, _, _, _, _, msg = event.pull("modem_message")
					if msg ~= "EOF" then
						file[input_method](file, msg)
					else
						print("file received")
						break
					end
				end
				file:close()
			end
		end
	--end
else
	local input_method, input_param = "read", require("tty").getViewport()

	--for i = 1, #args do
		local arg = shell.resolve(args[2])
		if fs.isDirectory(arg) then
			io.stderr:write(string.format('netcat %s: Is a directory\n', arg))
			os.exit(1)
		else
			local file, reason
			if args[2] == "-" then
				file, reason = io.stdin, "missing stdin"
				input_method, input_param = "readLine", false
			else
				file, reason = fs.open(arg)
			end
			if not file then
				io.stderr:write(string.format("netcat: %s: %s\n", args[i], tostring(reason)))
				os.exit(1)
			else
				repeat
					local chunk = file[input_method](file, input_param)
					if chunk then
						--io.write(chunk)
						modem.broadcast(port, chunk)
					end
				until not chunk
				modem.broadcast(port, "EOF")
				print("file sent")
				file:close()
			end
		end
	--end
end