I'm trying to get a response from specific requests via the write function.

I'm connected to an equipment via the net module (which is the only way to municate with it). Currently, I have an .on('data',function) to listen to responses from the said equipment. I can send mands via the write functions to which I am expecting to receive a line of response. How can I go about doing this?

Current code:

server = net.Socket();

// connect to server
server.connect(<port>,<ip>,()=>{
    console.log("Connected to server!");
});

// log data ing from the server
server.on("data",(data)=>{
    console.log(''+data);
});

// send mand to server
exports.write = function(mand){
    server.write(mand+"\r\n");
};

This is a working code. Sending a mand to the equipment via server.write returns a response which right now only appears in Terminal. I'd like to return that response right after the write request. Preferably within the exports.write function.

I'm trying to get a response from specific requests via the write function.

I'm connected to an equipment via the net module (which is the only way to municate with it). Currently, I have an .on('data',function) to listen to responses from the said equipment. I can send mands via the write functions to which I am expecting to receive a line of response. How can I go about doing this?

Current code:

server = net.Socket();

// connect to server
server.connect(<port>,<ip>,()=>{
    console.log("Connected to server!");
});

// log data ing from the server
server.on("data",(data)=>{
    console.log(''+data);
});

// send mand to server
exports.write = function(mand){
    server.write(mand+"\r\n");
};

This is a working code. Sending a mand to the equipment via server.write returns a response which right now only appears in Terminal. I'd like to return that response right after the write request. Preferably within the exports.write function.

• javascript
• node.js
• sockets

1 Answer 1

Add a callback argument to your exports.write function can solve your problem.

exports.write = function(mand, callback){
    server.write(mand+"\r\n");
    server.on('data', function (data) {
        //this data is a Buffer object
        callback(null, data)
    });

    server.on('error', function (error) {
        callback(error, null)
    });
};

call your write function

var server = require('./serverFilePath')
server.write('callback works', function(error, data){
    console.log('Received: ' + data)
})