Readline module with socket I/O

[linchun huang]

Hello, I am building a telnet server with node js.

Has anyone ever used the readline module with socket as input and output?

i.e. readline.createInterface(socket, socket);

It seems everything goes wrong when I use socket as I/O

Here is my code:

===============================================

/*

 * Callback method executed when a new TCP socket is opened.

 */

function newSocket(socket) {

//console.info(socket);

var option = {

input: socket,

output: socket,

terminal:true

};

var rl =readline.createInterface(option);

rl.write("Welcome to the Telnet server!\n");//Works fine

rl.setPrompt(">");

rl.prompt();

rl.on('line', function (line){//On reading a line!

line = line.trim();

console.info("Read a line!")

if(line === "@quit") {

socket.write('Goodbye!\n');

closeSocket(socket);//The function is defined elsewhere

}else if (line === "enable") {

socket.write("Enter enable mode!\n")

rl.setPrompt("#");

}else{

socket.write('echo:'+line+'\n');

}

rl.prompt();

});

};

// Create a new server and provide a callback for when a connection occurs

var server = net.createServer(newSocket);

server.listen(8888);

console.info('Server has started!');

============================================

After I telnet into the server and input 'abc', the results shown in the client are:

Welcome to the Telnet server!

>abc  //Input abc

abc

>echo:abc

>echo:echo:abc

============================================

And the server side:

Server has started!

Read a line!

Read a line!

============================================

It seems it reads twice after I send my input, how could this happen?

Any alternative for building a telnet server with completion function of NodeJS is also welcome.

Thank you so much!