UNIX domain sockets

client.js

var net = require('net');

connect();

function connect() {
  var client = net.connect('/tmp/test.sock', function() { //'connect' listener
    console.log('client connected');
    client.write('world!');
    
    function ping() {
      if(client.writable) {
        client.write('ping');
        setTimeout(ping, 1000);
      }
    }
    ping();
  });
  client.on('error', function(err) {
    if(err.code == 'ECONNREFUSED') {
      return setTimeout(connect, 1000);
    }
    throw err
  });
  client.on('data', function(data) {
    console.log(data.toString());
  });
  client.on('end', function() {
    console.log('client disconnected');
    connect();
  });
}

server.js

var net = require('net')
  , fs = require('fs')
  ;
var server = net.createServer(function(c) { //'connection' listener
  console.log('server connected');
  c.on('end', function() {
    console.log('server disconnected');
  });
  c.write('hello');
  c.pipe(c);
});
server.listen('/tmp/test.sock', function() { //'listening' listener
  fs.chmod('/tmp/test.sock', 0700, function(err) {
    if(err) throw err;
    console.log('server bound');
  })
});