I'm trying to use named pipes in my application. The problem is when I try to connect to the named pipe before the server is running, I get the following error:
events.js:141
throw er; // Unhandled 'error' event
^
Error: connect ENOENT \\?\pipe\\testpipe
at Object.exports._errnoException (util.js:870:11)
at exports._exceptionWithHostPort (util.js:893:20)
at PipeConnectWrap.afterConnect [as oncomplete] (net.js:1062:14)
How can I check if the pipe exists before attempting to connect to it?
Note: Wrapping my connect code in a try-catch doesn't prevent the error.
Here is my code:
var net = require('net');
var addr = '\\\\?\\pipe\\testpipe';
var client = net.createConnection({ path: addr }, function() {
console.log("Connected");
client.on('data', function(data) {
console.log("Recieved: " + data);
});
client.on('error', function(){
console.log(arguments);
});
}.bind(this));
Using the domain module prevents a fatal error. The following code can be used to safely run the connect code.
Not what I was hoping for, but the closed solution since there have been no answers.
var net = require('net');
var domain = require('domain');
var addr = '\\\\?\\pipe\\testpipe';
var d = domain.create();
d.on('error', function(err) {
console.error(err);
});
d.run(function() {
var client = net.createConnection({ path: addr }, function() {
console.log("Connected");
client.on('data', function(data) {
console.log("Recieved: " + data);
});
client.on('error', function(){
console.log(arguments);
});
}.bind(this));
});
make the socket, then listen for an error event, then call connect and it won't be thrown: https://nodejs.org/api/net.html#net_event_error_1
Related
I am working on a machine with Arduino motors for rotation on yaw and pitch axis. Also I have a nodejs server implementation to send data to machine (list of coordinates). For this purpose I have implemented a TCPClient class in TCP_Client.js as following:
var net = require('net');
/***********************************************************************************************************************
---------------------------------------------------Client TCP socket----------------------------------------------------
* *********************************************************************************************************************/
const port = 5303;
const host = 'localhost';
// creating a custom socket client and connecting it....
var client;
class TCPClient {
constructor(host, port) {
this.host = host;
this.port = port;
client = new net.Socket();
client.connect({
port: this.port,
host: this.host
});
this.onConnect();
}
onConnect() {
client.on('connect',function(){
console.log('Client: connection established with server');
console.log('---------client details -----------------');
var address = client.address();
var port = address.port;
var family = address.family;
var ipaddr = address.address;
console.log('Client is listening at port' + port);
console.log('Client ip :' + ipaddr);
console.log('Client is IP4/IP6 : ' + family);
});
client.on('drain', function(){
console.log("DRAIN");
});
this.setEncoding();
client.on('data', function(data) {
console.log("RECEIVED");
client.end();
});
client.on('end', function(){
console.log("END");
});
}
setEncoding() {
console.log("setEncoding");
client.setEncoding('utf8');
}
onData(data) {
console.log("DATA= ", data);
client.write(data);
}
end() {
client.end();
}
close() {
client.close();
}
}
//CREATE A TCP CLIENT OBJECT
exports.newTCPclient = function (host, port) {
console.log("CONSTRUCT TCP CLIENT");
var tc = new TCPClient(host, port);
return tc;
}
In server.js I initialize a global TCPClient as follows:
const port = 5033;
const host = '192.168.100.20';
var tcp_client = tcpclient.newTCPclient(host, port);
I send the coordinates merged in a text variable named coords as follows:
tcp_client.onData(coords);
Everytime I move the arduino motors I repeat this but after a short while I encounter this error:
events.js:174
throw er; //Unhandled 'error' event
Error: read ECONNRESET
at TCP.onStreamRead(internal/stream_base_commons.js:111:27)
Emitted 'error' event at:
at emitErrorNT (internal/streams/destroy.js:91:8)
at emitErrorAndCloseNT (internal/streams/destroy.js:59:3)
at process. tckCallback (internal/process/next_tick.js:63:19)
I am not very fluent with connections. Is it related to the TCP client class? If so how can I fix it?
Thank you for all the help.
ECONNRESET means the other side of the TCP conversation abruptly closed its end of the connection. Make sure it's closing the connection properly at the receiving end.
use --abort-on-uncaught-exception node option when running code, it will show you verbose report
I am developing socket application in my server with node js. I am just listening 9000 port. I am checking the data that client sent to this tcp port, if a client made http request, I kick client from server. Because some bots in the internet does that and I dont want them in my system. Due to test purposes, I try to connect that port with a browser, hold down F5 refresh button continuously, then application crashes immediately. I am simulating the DDOS attacks in my port by this way. The error message as follows:
events.js:183
throw er; // Unhandled 'error' event
^
Error: read ECONNRESET
at _errnoException (util.js:992:11)
at TCP.onread (net.js:618:25)
And here is my basic TCP listener code
var net = require("net");
var server = net.createServer();
server.on("error", err =>
{
console.log("error handled, error is : %s",err);
});
server.on("connection",function(socket)
{
var remoteAddress = socket.remoteAddress;
console.log("new client connection %s",remoteAddress);
socket.end();
});
server.listen(9000, function()
{
console.log("I am listening.");
});
What can be done to save TCP port from HTTP connections and internet bots?
Put this under socket.end():
socket.on('error', function(error) {
console.log('Socket got problems: ', error.message);
});
full code:
var net = require("net");
var server = net.createServer();
server.on("error", err =>
{
console.log("error handled, error is : %s",err);
});
server.on("connection",function(socket)
{
var remoteAddress = socket.remoteAddress;
console.log("new client connection %s",remoteAddress);
socket.end();
socket.on('error', function(error) {
console.log('Socket got problems: ', error.message);
});
});
server.listen(9000, function()
{
console.log("I am listening.");
});
I’m trying to create a Node js TCP server and client. Currently I’m running the server on the IP address of 127.0.0.1:8080.
And my client is trying to connect to that IP. I have no idea as to why this is failing, Here is my code:
var net = require('net');
const readline = require('readline');
var clients = [];
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout
});
function OpenServer() {
var server = net.createServer(function(socket) {
socket.write('Echo server\n');
socket.name = socket.remoteAddress + ":" + socket.remotePort;
socket.write(socket.name + " joined the chat\n");
socket.on('data', function(data) {
socket.write('socket Received: ' + data + '\n');
});
socket.on('connect', function(data){
socket.write("new connection");
});
socket.pipe(socket);
}).listen(8080, '127.0.0.1');
}
function OpenClient() {
var client = new net.Socket();
client.connect(8080, "127.0.0.1", function() {
console.log('Connected');
});
client.on('data', function(data) {
console.log('Client Received: ' + data + '\n');
rl.question('How are you today? ', (answer) => {
// TODO: Log the answer in a database
client.write(`Thank you ${answer}`);
rl.close();
});
});
client.on('close', function() {
console.log('Connection closed');
});
}
OpenClient(); OpenServer();
Here is the error I get when i run the client.
Process crashed with: Error: connect ECONNREFUSED 127.0.0.1:8080
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1174:14)
I’d also like to say, I kind of don’t really know what the IP 127.0.0.1 is.
If anyone has a better solution or better way of doing this, I’m very open to here it.
I have set up a node program (actually two, one for the server and one for the client) but I get this error from my client every time I run it:
events.js:85
throw er; // Unhandled 'error' event
^
Error: connect ECONNREFUSED
The code for the server:
var net = require('net');
var server = net.createServer(function (socket) {
console.log('Connection from ' + socket.remoteAddress);
socket.end('hello world')
});
server.listen(7000, '0.0.0.0')
This works fine. As for my client code, not so much. Here is my client code:
var net = require('net');
var client = new net.Socket();
client.connect(7000, 'IP of server here'); // in my actual code, I used the actual ip, of course
client.on('data', function(data) {
console.log('Data: ' + data);
client.destroy();
});
client.on('close', function () {
console.log('Connection closed');
});
This is one of my first node programs, and it is my first using TCP, so expect a newbie mistake. Thanks in advance for the help.
You need to handle the "error" event to avoid the default exception throw:
client.on('error', (error) => {
// treat error here
})
I am attempting to use the net lib in Node.js to do simple message passing. In the example on Nodejs.org they provide the following code as a basic echo server:
var net = require('net');
var server = net.createServer(function(c) { //'connection' listener
console.log('server connected');
c.on('end', function() {
console.log('server disconnected');
});
c.write('hello\r\n');
c.pipe(c);
});
server.listen(8124, function() { //'listening' listener
console.log('server bound');
});
and a client for said server:
var net = require('net');
var client = net.connect({port: 8124},
function() { //'connect' listener
console.log('client connected');
client.write('world!\r\n');
});
client.on('data', function(data) {
console.log(data.toString());
client.end();
});
client.on('end', function() {
console.log('client disconnected');
});
The example above works, however, if you remove the client.end(); from the client code and force close the script on the client end (simulating a client crashing) the server crashes as well with the error:
Error: read ECONNRESET
at errnoException (net.js:904:11)
at TCP.onread (net.js:558:19)
I attempted to catch the error in the server code with c.on("error",function(){}) as well as server.on('error', function (e) {}); but in both cases the server still crashes when the client disconnects without using client.end()
What is the propper way of checking for this error so that the server does a console.log('connection reset by peer') instead of crashing?
UPDATE:
I tried this same code on my linux box and it seems to work just fine ... so why does it work in linux but not in windows?
you can catch that error by adding this code inside yours 'createServer' function:
process.on('uncaughtException', function (err) {
console.error(err.stack);
console.log("Node NOT Exiting...");
});