View difference between Paste ID: 7NqBFeuK and MVSQ9ci4

 -- File Transfers over CRFv3.1
 
 -- Packet structure:
 -- [1] : Ident string
 -- [2] : Action
 -- [3] : Target
 -- [4] : Data Parameter
 -- [5] : Binary Flag
 
 if not LANClient then
 	error("LAN Client API not loaded.")
 end
 
 function readFile(server, file, binary)
 	LANClient.send(server, textutils.serialize({"FileTransfer", "read", file, binary}))
 	while true do
-		local sender, data = LANClient.receive(5)
+	local sender, data = LANClient.receive(5)
 		if not sender then
 			return false, "Server timed out"
 		elseif sender == server then
 			data = textutils.unserialize(data)
 			if type(data) == "table" then
 				if data[1] == "FileTransfer" then
 					if data[2] == "Error" then
 						return false, data[3]
 					elseif data[2] == "data" then
 						return true, data[3]
 					else
 						return false, "Unknown response"
 					end
 				end
 			end
 		end
 	end
 end
 
 function listFiles(server, dir)
 	LANClient.send(server, textutils.serialize({"FileTransfer", "list", file}))
 	local sender, data = LANClient.receive(5, server)
 	if not sender then
 		return false, "Server timed out"
 	else
 		data = textutils.unserialize(data)
 		if type(data) == "table" then
 			if data[1] == "FileTransfer" then
 				if data[2] == "Error" then
 					return false, data[3]
 				elseif data[2] == "list" then
 					return true, data[3]
 				else
 					return false, "Unknown response"
 				end
 			end
 		end
 	end
 end
 
 function writeFile(server, file, data, binary)
 	LANClient.send(server, textutils.serialize({"FileTransfer", "write", file, binary}))
 	local sender, data = LANClient.receive(5, server)
 	if not sender then
 		return false, "Server timed out"
 	else
 		data = textutils.unserialize(data)
 		if type(data) == "table" then
 			if data[1] == "FileTransfer" then
 				if data[2] == "Error" then
 					return false, data[3]
 				elseif data[2] == "Okay" then
 					return true
 				else
 					return false, "Unknown response"
 				end
 			end
 		end
 	end
 end
 
 function deleteFile(server, file)
-	LANClient.send(server, textutils.serialize({"FileTransfer", "delete", file}))
+	return false, "This action is prohibited on your system"
 end
 
 function mkDir(server, dir)
 	LANClient.send(server, textutils.serialize({"FileTransfer", "mkdir", dir}))
 	local sender, data = LANClient.receive(5, server)
 	if not sender then
 		return false, "Server timed out"
 	else
 		data = textutils.unserialize(data)
 		if type(data) == "table" then
 			if data[1] == "FileTransfer" then
 				if data[2] == "Error" then
 					return false, data[3]
 				elseif data[2] == "Okay" then
 					return true
 				else
 					return false, "Unknown response"
 				end
 			end
 		end
 	end
 end
 
 if shell then
 	local file = fs.open(shell.getRunningProgram(), "r")
 	if file then
 		local l = file.readLine()
 		file.close()
 		if string.match(l, "File Transfers") then
 			local args = {...}
 			if #args == 0 then
 				print("FTP -- File transfer interface and API")
 				print(string.rep("-", term.getSize()))
 				print("Usage: ftp [action] [server] [target] [params]")
 				print("Actions:")
 				print("read (\"ftp read [server] [remoteFile] [localFile]\"): Get a file.")
 				print("write (\"ftp write [server] [localFile] [remoteFile]\"): Send a file.")
 				print("mkdir (\"ftp mkdir [server] [remoteDir]\"): Make a directory.")
 				print("delete (\"ftp delete [server] [remoteFile]\"): Delete a file.")
 				print("list (\"ftp list [server] [remoteDir]\"): Get a directory listing.")
 			elseif #args == 4 then
 				if args[1] == "read" then
 					local stat, data = readFile(tonumber(args[2]), args[3], false)
 					if stat then
 						local f = fs.open(args[4], "w")
 						f.write(data)
 						f.close()
 						print("Data written to "..args[4])
 					else
 						print("Could not get file: "..data)
 					end
 				elseif args[1] == "write" then
 					local f = fs.open(args[3], "r")
 					data = f.readAll()
 					f.close()
 					local stat, err = writeFile(tonumber(args[2]), args[4], data, false)
 					if stat then
 						print("File successfully transferred.")
 					else
 						print("Could not transfer file: "..err)
 					end
 				end
 			elseif #args == 3 then
 				if args[1] == "mkdir" then
 					local stat, err = mkDir(tonumber(args[2]), args[3])
 					if stat then
 						print("Directory successfully created.")
 					else
 						print("Could not make directory: "..err)
-                    if fs.exists(args[3]) then
+
-                        local f = fs.open(args[3], "r")
+
-                        data = f.readAll()
+
-                        f.close()
+
-                        local stat, err = writeFile(tonumber(args[2]), args[4], data, false)
+
-                        if stat then
+
-                            print("File successfully transferred.")
+
-                        else
+
-                            print("Could not transfer file: "..err)
+
-                        end
+
-                    else
+
-                        print("File does not exist: "..args[3])
+
-                    end
+
 						print("Could not get directory listing: "..err)
 					end
 				end
 			end
 		end
 	end
 end