View difference between Paste ID: sHRw0WxH and 5Z7uvCXQ

 local ftp_client = [[
 -- socket_client class(client)
 local socket_client = {
 	_modem         = false;
 	_channel       = 0;
 	_reply_channel = 0;
 	_side 	       = "top";
 	_stack		   = {};
 }
 socket_client.__index = socket_client
 
 socket_client.__call = function(self, ch, rep_ch)
 	local sides = {
 		"right", "left",
 		"top", "bottom",
 		"front", "back"
 	}
 
 	local m = nil
 	local side = "none"
 	for k, v in ipairs(sides) do
 		if peripheral.getType(v) == "modem" then
 			side = v
 			break
 		end
 	end
 
 	if side == "none" then
 		return -1
 	end
 
 	m = peripheral.wrap(side)
 
 	local t = {
 		_channel = ch;
 		_reply_channel = rep_ch;
 		_side 	 = s or "top";
 		_modem 	 = m;
 	}
 	setmetatable(t, socket_client)
 
 	return t
 end
 
 function socket_client:connect(timeout)
 	if not self._modem then return end
 
 	self:write("request_connect")
 	local timer_id = 0
 	if timeout then timer_id = os.startTimer(timeout) end
 
 	while true do
 		local ev, p1, p2, p3, p4 = os.pullEvent()
 
 		if timeout and ev == "timer" and p1 == timer_id then
 			return false
 		elseif ev == "modem_message" then
 			if p4:find("success") ~= nil then
 				return true
 			end
 		end
 	end
 
 	self._modem.closeAll()
 
 	return false
 end
 
 function socket_client:listen()
 	if not self._modem then return end
 
 	self._modem.open(self._channel)
 	self._modem.open(self._reply_channel)
 
 	while true do
 		local ev, p1, p2, p3, p4 = os.pullEvent("modem_message")
 		if p2 == self._reply_channel then
 			return p4
 		end
 	end
 
 	self._modem.closeAll()
 
 	return ""
 end
 
 function socket_client:read()
 	return self:listen()
 end
 
 function socket_client:write(msg)
 	if not self._modem then return end
 
 	self._modem.open(self._channel)
 	self._modem.transmit(self._channel, self._reply_channel, msg)
 	self._modem.closeAll()
 end
 setmetatable(socket_client, socket_client)
 
 local text_utils = {}
 text_utils.last = function(str, tok)
 	local pos = -1
 
 	while str:find(tok, pos + 1) ~= nil do
 		pos = str:find(tok, pos + 1)
 	end
 
 	return (pos < 0 and 0 or pos - 1)
 end
 
 function string:split(sep)
         local sep, fields = sep or ":", {}
         local pattern = string.format("([^%s]+)", sep)
         self:gsub(pattern, function(c) fields[#fields+1] = c end)
         return fields
 end
 
 local arg = {...}
 
 if arg[1] ~= nil and arg[1]:lower() == "help" then
 	print("Usage:\nFTP_client [server channel] [client channel]")
 	return
 end
 
 local ch = arg[1] == nil and 12 or (tonumber(arg[1]) == nil and 12 or tonumber(arg[1]))
 local reply_ch = arg[2] == nil and 13 or (tonumber(arg[2]) == nil and 13 or tonumber(arg[2]))
 local socket = socket_client(ch, reply_ch)
 
 if type(socket) == "number" and socket == -1 then
 	print("No modem found.")
 	return
 end
 
 local remote_dir = "/"
 local local_dir = shell.getRunningProgram():sub(0, text_utils.last(shell.getRunningProgram(), "/"))
 local history = {}
 
 local function cmd_cd(c, str)
 	socket:write("cmd:" .. str)
 	local d = socket:read(1)
 	if d == -1 then
 		print("Error reading from server")
 	else
 		remote_dir = d
 	end
 
 	return socket:read(1)
 end
 
 local function cmd_ls(c, str)
 	socket:write("cmd:" .. str)
 	local l = socket:read(1)
 	if l == -1 then
 		print("Error reading from server.")
 	else
 		if l ~= "" then
 			print(l)
 		end
 	end
 end
 
 local function cmd_lls(c, str)
 	local p = c[2]
 	if not fs.exists(local_dir .. (p and "/" .. p or "")) then
 		return "no_such_file"
 	end
 
 	local l = fs.list(local_dir .. (p and "/" .. p or ""))
 	local s = ""
 	for k, v in ipairs(l) do
 		s = s .. v .. "\n"
 	end
 	s = s:sub(1, #s - 1)
 	print(s)
 end
 
 local function cmd_mkdir(c, str)
 	socket:write("cmd:" .. str)
 	local l = socket:read(1)
 	if l == -1 then
 		print("Error reading from server.")
 	else
 		return l
 	end
 end
 
 local function cmd_lcd(c, str)
 	local p = c[2]
 	if p == ".." then
 		local_dir = local_dir:sub(1, text_utils.last(local_dir, "/"))
 	elseif p ~= "." then
 		if fs.isDir(local_dir .. "/" .. p) then
 			local_dir = local_dir .. "/" .. p
 		else
 			return "no_such_file"
 		end
 	end
 
 	return local_dir .. "/"
 end
 
 local function cmd_delete(c, str)
 	socket:write("cmd:" .. str)
 	local l = socket:read(1)
 	if l == -1 then
 		print("Error reading from server.")
 	else
 		return l
 	end
 end
 
 local function cmd_rmdir(c, str)
 	socket:write("cmd:" .. str)
 	local l = socket:read(1)
 	if l == -1 then
 		print("Error reading from server.")
 	else
 		return l
 	end
 end
 
 local function cmd_put(c, str)
 	local t = os.time()
 	if not c[2] then
 		return "wrong_args"
 	end
 
 	if fs.isDir(local_dir .. "/" .. c[2]) then
 		return "custom_err Cannot upload directory. Use 'rput' or 'mput' instead."
 	end
 
 	if not fs.exists(local_dir .. "/" .. c[2]) then
 		return "no_such_file"
 	end
 
 	socket:write("cmd:" .. str)
 	local l = socket:read(1)
 	if l == -1 then
 		print("Error reading from server.")
 		return "unknown_error"
 	elseif l == "ready" then
 		local f = io.open(local_dir .. "/" .. c[2], "r")
 		local data = f:read("*a")
 		f:close()
 
 		socket:write(data)
 
 		local res = socket:read(1)
 		if res == -1 then
 			return "unknown_error"
 		else
 			return (res == "" and "custom_err Wrote " .. #data .. " bytes in " .. (os.time() - t) * 0.0138 .. " seconds." or res)
 		end
 	else
 		return l
 	end
 end
 
 local function putfiles(dir, abs)
 	local ret = cmd_mkdir({}, "mkdir " .. abs)
 	if ret ~= "" then return ret end
 
 	local l = fs.list(dir)
 
 	for k, v in ipairs(l) do
 		if fs.isDir(local_dir .. "/" .. dir .. "/" .. v) then
 			putfiles(local_dir .. "/" .. dir .. "/" .. v, abs .. "/" .. v)
 		else
 			local ret = cmd_put({"put", local_dir .. "/" .. dir .. "/" .. v, abs .. "/" .. v}, "put asd " .. abs .. "/" .. v)
 			if ret ~= "" then
 				return ret
 			end
 		end
 	end
 end
 
 local function cmd_rput(c, str)
 	if not c[2] then
 		return "wrong_args"
 	end
 
 	if not fs.exists(local_dir .. "/" .. c[2]) then
 		return "no_such_file"
 	end
 
 	if not fs.isDir(local_dir .. "/" .. c[2]) then
 		return "custom_err Given path is not a directory. Use 'put' instead."
 	end
 
 	ret = putfiles(local_dir .. "/" .. c[2], c[3] or c[2])
 	return ret
 end
 
 local function cmd_get(c, str)
 	if not c[2] then
 		return "wrong_args"
 	end
 
 	if fs.isDir(local_dir .. "/" .. (c[3] or c[2])) then
 		return "custom_err Cannot overwrite directory."
 	end
 
 	if fs.exists(local_dir .. "/" .. (c[3] or c[2])) then
 		io.write("Overwrite file '" .. (c[3] or c[2]) .. "? (y/n) ")
 		local ans = io.read()
 
 		if ans:lower() ~= "y" and ans:lower() ~= "yes" then
 			return ""
 		end
 	end
 
 	socket:write("cmd:" .. str)
 
 	local ret = socket:read()
 	if ret == "ok" then
 		socket:write("ready")
 		local data = socket:read()
 
 		local f = io.open(local_dir .. "/" .. (c[3] or c[2]), "w")
 		f:write(data)
 		f:close()
 
 		ret = socket:read()
 		return ret
 	else
 		return ret
 	end
 end
 
 local function cmd_rget(c, str)
 	if not c[2] then
 		return "wrong_args"
 	end
 
 	if fs.isDir(local_dir .. "/" .. (c[3] or c[2])) then
 		return "custom_err Cannot overwrite directory."
 	end
 
 	if fs.exists(local_dir .. "/" .. (c[3] or c[2])) then
 		io.write("Overwrite file '" .. (c[3] or c[2]) .. "? (y/n) ")
 		local ans = io.read()
 
 		if ans:lower() ~= "y" and ans:lower() ~= "yes" then
 			return ""
 		end
 	end
 
 	socket:write("cmd:" .. str)
 
 	local ret = socket:read()
 
 	if ret == "ok" then
 		socket:write("ready")
 		local p = socket:read()
 		while p ~= "__getfiles_done__" do
 			if p:sub(1, 1) == "d" then
 				fs.makeDir(local_dir .. "/" .. p:sub(2))
 			else
 				local data = socket:read()
 				local f = io.open(local_dir .. "/" .. p:sub(2), "w")
 				f:write(data)
 				f:close()
 			end
 
 			p = socket:read()
 		end
 
 		ret = socket:read()
 
 		return ret
 	else
 		return ret
 	end
 end
 
 local help_text = {
 	["cd"] = "Usage:\ncd <dir>\n\nChanges directory to <dir> on remote\nmachine.";
 
 	["lcd"] = "Usage:\ncd <dir>\n\nChanges directory to <dir> on local\nmachine.";
 
 	["ls"] = "Usage:\nls [dir]\n\nLists files in current directory on remote\nmachine.\nIf [dir] is provided, files in that directory\nwill be listed instead.";
 
 	["lls"] = "Usage:\nls [dir]\n\nLists files in current directory on local\nmachine.\nIf [dir] is provided, files in that directory\nwill be listed instead.";
 
 	["quit"] = "Usage:\nquit|bye\n\nCloses the connection and exists the program.";
 
 	["pwd"] = "Usage:\npwd\n\nPrints the current directory on the remote\nmachine.";
 
 	["mkdir"] = "Usage:\nmkdir <dir>\n\nCreates the directory <dir> on the remote\nmachine.";
 
 	["delete"] = "Usage:\ndelete <file>\n\nDeletes the file <file> on the remote machine.\nCannot delete directories.";
 
 	["rmdir"] = "Usage:\nrmdir <dir>\n\nRemoves the directory <dir> on the remote\nmachine. Cannot delete files.";
 
 	["put"] = "Usage:\nput <local/path> [remote/path]\n\nUploads a file to the remote machine.\nIf [remote/path] is specified, it will upload\nto that filename, otherwise it will upload to\nas <local/path> on remote machine.\nCannot upload directories.";
 
 	["rput"] = "Usage:\nrput|mput <local/path> [remote/path]\n\nUploads a directory to the remote machine.\nIf [remote/path] is specified, it will upload\nto that filename, otherwise it will upload to\nas <local/path> on remote machine.\nCannot upload single files.";
 
 	["get"] = "Usage:\nget <remote/path> [local/path]\n\nDownloads a single file from <remote/path> on\nthe remote machine. If [local/path] is specified,\nit will save there, otherwise in <remote/path>.\nCannot download directories. Use 'rget' or 'mget'.";
 
 	["rget"] = "Usage:\nrget|mget <remote/path>\n\nDownloads the directory <remote/path> from the\nremote machine. The directory is saved as\n<remote/path>";
 }
 help_text["bye"] = help_text["quit"]
 help_text["mput"] = help_text["rput"]
 help_text["mget"] = help_text["rget"]
 
 local function cmd_help(c, str)
 	if c[2] ~= nil then
 		local text = help_text[c[2] ]
 		if text == nil then
 			return "custom_err No help available for '" .. c[2] .. "'"
 		end
 
 		print(text .. "\n")
 
 		return ""
 	end
 
 	print("Help for FTP:\ncd <dir>      - change directory on remote\nlcd <dir>     - change directory locally\nls [dir]      - list files on remote\nlls [dir]     - list files locally\nquit/bye      - close connection\npwd           - print current remote dir\nmkdir <dir>   - create directory on remote\ndelete <file> - remove file on remote\nrmdir <dir>   - remove directory on remote\nput <file> [remote_file] - upload file\nrput/mput <dir> [remote_dir] - upload dir\nget <remote_file> [file] - download file\nhelp          - show this screen\nhelp <cmd>    - help for specific command\n")
 	return ""
 end
 
 local function main()
 	print("Connecting...")
 	if socket:connect(2) == false then
 		return false
 	end
 
 	while true do
 		io.write(local_dir .. "> ")
 		local cmd = read(nil, history)
 		table.insert(history, cmd)
 
 		local w = string.split(cmd, " ")
 
 
 		local ret = ""
 
 		if w[1] ~= nil then
 			if w[1]:lower() == "cd" then
 				ret = cmd_cd(w, cmd)
 			elseif w[1]:lower() == "ls" then
 				ret = cmd_ls(w, cmd)
 			elseif w[1]:lower() == "lls" then
 				ret = cmd_lls(w, cmd)
 			elseif w[1]:lower() == "lcd" then
 				ret = cmd_lcd(w, cmd)
 			elseif w[1]:lower() == "quit" or w[1]:lower() == "bye" then
 				socket:write("request_disconnect")
 				return true
 			elseif w[1]:lower() == "pwd" then
 				print(remote_dir)
 			elseif w[1]:lower() == "mkdir" then
 				ret = cmd_mkdir(w, cmd)
 			elseif w[1]:lower() == "delete" then
 				ret = cmd_delete(w, cmd)
 			elseif w[1]:lower() == "rmdir" then
 				ret = cmd_rmdir(w, cmd)
 			elseif w[1]:lower() == "put" then
 				ret = cmd_put(w, cmd)
 			elseif w[1]:lower() == "mput" or w[1]:lower() == "rput" then
 				ret = cmd_rput(w, cmd)
 			elseif w[1]:lower() == "get" then
 				ret = cmd_get(w, cmd)
 			elseif w[1]:lower() == "rget" or w[1]:lower() == "mget" then
 				ret = cmd_rget(w, cmd)
 			elseif w[1]:lower() == "help" or w[1] == "?" then
 				ret = cmd_help(w, cmd)
 			else
 				ret = "unknown_command"
 			end
 		end
 
 		if ret == "unknown_error" then
 			print("Unknown error.")
 		elseif ret == "unknown_command" then
 			print("Unknown command. Try 'help'")
 		elseif ret == "wrong_args" then
 			print("Insufficient arguments. Try 'help'")
 		elseif ret == "no_such_file" then
 			print("No such file or directory.")
 		elseif ret == "invalid_path" then
 			print("Invalid path.")
 		elseif ret == "already_exists" then
 			print("File or directory already exists.")
 		elseif ret == "not_allowed" then
 			print("Insufficient permissions.")
 		elseif type(ret) == "string" and ret:sub(0, string.len("custom_err")) == "custom_err" then
 			print(ret:sub(string.len("custom_err") + 2))
 		end
 	end
 
 	return true
 end
 
 term.clear()
 term.setCursorPos(1, 1)
 print("Welcome to FTP!\nFor a list of commands, run 'help'")
 if main() == true then
 	term.clear()
 	term.setCursorPos(1, 1)
 	print("Thanks for using FTP!")
 else
 	print("Unable to connect.")
 end
 ]]
 
 local ftp_server = [[
 local text_utils = {}
 text_utils.last = function(str, tok)
 	local pos = -1
 
 	while str:find(tok, pos + 1) ~= nil do
 		pos = str:find(tok, pos + 1)
 	end
 
 	return (pos < 0 and 0 or pos - 1)
 end
 
 function string:split(sep)
         local sep, fields = sep or ":", {}
         local pattern = string.format("([^%s]+)", sep)
         self:gsub(pattern, function(c) fields[#fields+1] = c end)
         return fields
 end
 
 -- Socket server class
 local socket_server = {
 	_modem	       = false;
 	_channel       = -1;
 	_reply_channel = 0;
 	_side 	       = "top";
 	_connected     = false;
 }
 socket_server.__index = socket_server
 
 socket_server.__call = function(self, rep_ch)
 	local sides = {
 		"right", "left",
 		"top", "bottom",
 		"front", "back"
 	}
 
 	local m = nil
 	local side = "none"
 	for k, v in ipairs(sides) do
 		if peripheral.getType(v) == "modem" then
 			side = v
 			break
 		end
 	end
 
 	if side == "none" then
 		return -1
 	end
 
 	m = peripheral.wrap(side)
 
 	local t = {
 		_side 	 	   = s or "top";
 		_reply_channel = rep_ch;
 		_modem 	  	   = m;
 	}
 	setmetatable(t, socket_server)
 
 	return t
 end
 
 function socket_server:accept(ch, timeout)
 	if self._connected then return end
 	if not self._modem then return end
 
 	self._modem.open(ch)
 
 	local timer_id = 0
 	if timeout then timer_id = os.startTimer(timeout) end
 
 	while true do
 		local ev, p1, p2, p3, p4 = os.pullEvent()
 
 		if timeout and ev == "timer" and p1 == timer_id then
 			return false
 		elseif ev == "modem_message" then
 			if p4:find("request_connect") ~= nil then
 				print("Client connected on channel " .. p2)
 				self._channel = p2
 				self._connected = true
 				self._modem.transmit(self._channel, self._reply_channel, "success")
 				return true
 			end
 		end
 	end
 
 	self._modem.closeAll()
 
 	return false
 end
 
 function socket_server:accept_any(timeout)
 	if self._connected then return end
 	if not self._modem then return end
 
 	for i = 0, 1000 do
 		self._modem.open(i)
 	end
 
 	local timer_id = 0
 	if timeout then timer_id = os.startTimer(timeout) end
 
 	while true do
 		local ev, p1, p2, p3, p4 = os.pullEvent()
 
 		if timeout and ev == "timer" and p1 == timer_id then
 			return false
 		elseif ev == "modem_message" then
 			if p4:find("request_connect") ~= nil then
 				print("Client connected on channel " .. p3)
 				self._channel = p3
 				self._connected = true
 				self._modem.transmit(self._channel, self._reply_channel, "success")
 				return true
 			end
 		end
 	end
 
 	self._modem.closeAll()
 
 	return false
 end
 
 function socket_server:listen()
 	if not self._modem then return end
 
 	while true do
 		if self._channel ~= -1 then
 			self._modem.open(self._channel)
 			self._modem.open(self._reply_channel)
 
 			local ev, p1, p2, p3, p4 = os.pullEvent("modem_message")
 			if p2 == self._reply_channel then
 				return p4
 			end
 
 			self._modem.closeAll()
 		end
 	end
 
 	return ""
 end
 
 function socket_server:read()
 	local r = self:listen()
 	if r == "request_disconnect" then
 		print("Client on channel ".. self._channel .. " disconnected.")
 		self._connected = false
 	end
 	return r
 end
 
 function socket_server:write(msg)
 	if not self._modem then return end
 
 	self._modem.open(self._channel)
 	self._modem.transmit(self._channel, self._reply_channel, msg)
 	self._modem.closeAll()
 end
 setmetatable(socket_server, socket_server)
 
 local arg = {...}
 
 _print = function(...)
 	if not bg then print(...) end
 end
 
 if arg[2] == nil and arg[1] ~= nil and (arg[1]:lower() == "-b" or arg[1]:lower() == "--background") then
 	arg[3] = arg[1]
 end
 
 if arg[1] ~= nil and arg[1]:lower() == "help" then
 	_print("Usage:\nFTP_server [channel] [options]\nIf the option -b is provided, the server will run in the background")
 	return
 end
 
 local ch = arg[1] == nil and 12 or (tonumber(arg[1]) == nil and 12 or tonumber(arg[1]))
 
 local server = socket_server(ch)
 
 if type(server) == "number" and server == -1 then
 	_print("No modem found.")
 	return
 end
 
 local dir = ""
 local bg = false
 
 local function cd(p)
 	if p == ".." then
 		dir = dir:sub(1, text_utils.last(dir, "/"))
 	elseif p ~= "." then
 		if fs.isDir(dir .. "/" .. p) then
 			dir = dir .. "/" .. p
 		else
 			server:write(dir .. "/")
 			return "no_such_file"
 		end
 	end
 
 	server:write(dir .. "/")
 	return dir .. "/"
 end
 
 local function ls(p)
 	if not fs.exists(dir .. (p and "/" .. p or "")) then
 		server:write("")
 		return "no_such_file"
 	end
 
 	local l = fs.list(dir .. (p and "/" .. p or ""))
 	local s = ""
 	for k, v in ipairs(l) do
 		s = s .. v .. "\n"
 	end
 	s = s:sub(1, #s - 1)
 	server:write(s)
 
 	return ""
 end
 
 local function mkdir(p)
 	if fs.exists(dir .. "/" .. p) then
 		return "already_exists"
 	end
 
 	fs.makeDir(dir .. "/" .. p)
 
 	return ""
 end
 
 local function delete(p)
 	if not fs.exists(dir .. "/" .. p) then
 		return "no_such_file"
 	elseif fs.isReadOnly(dir .. "/" .. p) then
 		return "not_allowed"
 	elseif fs.isDir(dir .. "/" .. p) then
 		return "custom_err Cannot remove a directory. Use 'rmdir' instead."
 	end
 
 	fs.delete(dir .. "/" .. p)
 
 	return ""
 end
 
 local function rmdir(p)
 	if not fs.exists(dir .. "/" .. p) then
 		return "no_such_file"
 	elseif fs.isReadOnly(dir .. "/" .. p) then
 		return "not_allowed"
 	elseif not fs.isDir(dir .. "/" .. p) then
 		return "custom_err Cannot remove a file. Use 'delete' instead."
 	end
 
 	fs.delete(dir .. "/" .. p)
 
 	return ""
 end
 
 local function put(p)
 	if fs.isDir(dir .. "/" .. p) then
 		return "custom_err Cannot overwrite directory."
 	end
 
 	server:write("ready")
 	local data = server:read()
 	local f = io.open(dir .. "/" .. p, "w")
 	f:write(data)
 	f:close()
 
 	return ""
 end
 
 local function get(p)
 	if not fs.exists(dir .. "/" .. p) then
 		return "no_such_file"
 	end
 
 	if fs.isDir(dir .. "/" .. p) then
 		return "custom_err Cannot download directory. Use 'rget' or 'mget' instead."
 	end
 
 	server:write("ok")
 	local ret = server:read()
 	if ret ~= "ready" then
 		return "unknown_err"
 	end
 
 	local f = io.open(dir .. "/" .. p, "r")
 	local data = f:read("*a")
 	f:close()
 	server:write(data)
 
 	return ""
 end
 
 local function rget(p)
 	if not fs.exists(dir .. "/" .. p) then
 		return "no_such_file"
 	end
 
 	if not fs.isDir(dir .. "/" .. p) then
 		return "custom_err Cannot download single files.\nUse 'get' instead."
 	end
 
 	server:write("ok")
 
 	local function getfiles(path)
 		server:write("d" .. path)
 		local l = fs.list(dir .. "/" .. path)
 
 		for k, v in ipairs(l) do
 			if fs.isDir(dir .. "/" .. path .. "/" .. v) then
 				getfiles(dir .. "/" .. path .. "/" .. v)
 			else
 				server:write("f" .. path .. "/" .. v)
 
 				local ret = server:read()
 				if ret ~= "ready" then
 					return ret
 				end
 
 				local f = io.open(dir .. "/" .. path .. "/" .. v, "r")
 				local data = f:read("*a")
 				f:close()
 
 				server:write(data)
 			end
 		end
 	end
 
 	getfiles(p)
 	server:write("__getfiles_done__")
 end
 
 local function main()
 	server:accept_any()
 
 	while true do
 		if not server._connected then
 			server:accept_any()
 		end
 
 		local msg = server:read()
 
 		if msg:sub(1, 4) == "cmd:" then
 			local cmd = msg:sub(5)
 			_print("Command: " .. cmd)
 			cmd = string.split(cmd, " ")
 
 			if cmd[1]:lower() == "cd" then
 				if not cmd[2] then
 					server:write("wrong_args")
 				else
 					local ret = cd(cmd[2])
 					server:write(ret)
 				end
 			elseif cmd[1]:lower() == "ls" then
 				local ret = ls(cmd[2] or "")
 				server:write(ret)
 			elseif cmd[1]:lower() == "mkdir" then
 				if not cmd[2] then
 					server:write("wrong_args")
 				else
 					local ret = mkdir(cmd[2])
 					server:write(ret)
 				end
 			elseif cmd[1]:lower() == "delete" then
 				if not cmd[2] then
 					server:write("wrong_args")
 				else
 					local ret = delete(cmd[2])
 					server:write(ret)
 				end
 			elseif cmd[1]:lower() == "rmdir" then
 				if not cmd[2] then
 					server:write("wrong_args")
 				else
 					local ret = rmdir(cmd[2])
 					server:write(ret)
 				end
 			elseif cmd[1]:lower() == "put" then
 				if not cmd[2] then
 					server:write("wrong_args")
 				else
 					local ret = put((cmd[3] ~= nil and cmd[3] or cmd[2]))
 					server:write(ret)
 				end
 			elseif cmd[1]:lower() == "get" then
 				if not cmd[2] then
 					server:write("wrong_args")
 				else
 					local ret = get(cmd[2])
 					server:write(ret)
 				end
 			elseif cmd[1]:lower() == "rget" or cmd[1]:lower() == "mget" then
 				if not cmd[2] then
 					server:write("wrong_args")
 				else
 					local ret = rget((cmd[3] ~= nil and cmd[3] or cmd[2]))
 					server:write(ret)
 				end
 			else
 				server:write("unknown_command")
 			end
 		end
 	end
 
 	return ""
 end
 
 if arg[3] ~= nil and (arg[3]:lower() == "-b" or arg[3] == "--background") then
 	bg = true
 	term.clear()
 	term.setCursorPos(1, 1)
 	parallel.waitForAll(main, function() shell.run("shell") end)
 else
 	main()
 end
 ]]
 
 local arg = {...}
 
 if not arg[1] then print("Usage:\ninstall server|client") else
 	if arg[1]:lower() == "c" or arg[1]:lower() == "client" then
 		local f = io.open("ftp_client", "w")
 		f:write(ftp_client)
 		f:close()
 		print("Installed to 'ftp_client'.\nRun 'ftp_client help' for information about using it.")
 	elseif arg[1]:lower() == "s" or arg[1]:lower() == "server" then
 		local f = io.open("ftp_server", "w")
 		f:write(ftp_server)
 		f:close()
-		print("Installed to 'ftp_server'.\nRun 'ftp_server' help' for information about using it.")
+		print("Installed to 'ftp_server'.\nRun 'ftp_server help' for information about using it.")
 	end
 end