In nodejs, how do I check if a port is listening or in use

Question

I\'ll be very specific here in the hope that folks who understand this can edit to rephrase to the general situation.

Currently when you run "node debug", it sp

Answer 1

A variation on the following is what I used:

var net = require('net');

var portInUse = function(port, callback) {
    var server = net.createServer(function(socket) {
	socket.write('Echo server\r\n');
	socket.pipe(socket);
    });

    server.listen(port, '127.0.0.1');
    server.on('error', function (e) {
	callback(true);
    });
    server.on('listening', function (e) {
	server.close();
	callback(false);
    });
};

portInUse(5858, function(returnValue) {
    console.log(returnValue);
});

The actual commit which is a little more involved is https://github.com/rocky/trepanjs/commit/f219410d72aba8cd4e91f31fea92a5a09c1d78f8