browse-mdns.js

#!/usr/bin/env node

try {
  var util = require('util');
} catch(err) {
  var util = require('sys');
}

try {
  var args = require('arguments');
} catch(err) {
  console.log('Error: missing arguments module');
  console.log('install via: npm install arguments');
  process.exit(1);
}

var proto = 'tcp';
var svc = 'http';

args.parse([
  {'name': /^(-h|--help)$/, 'expected': null, 'callback': printHelp},
  {'name': /^(-p|--proto)$/, 'expected': /^(tcp|udp)$/, 'callback': setupProto},
  {'name': /^(-s|--service)$/, 'expected': /^([a-z]{1,})$/, 'callback': setupService}
  ],main,invalidArgument);
  
function printHelp (end) {
  console.log('browse-mdns.js [OPTIONS]');
  console.log('\t-p|--proto [PROTOCOL]....PROTOCOL is either tcp or udp (default: tcp)');
  console.log('\t-s|--service [SVC].......SVC is the service to browse for (default: http)');
  end();
  process.exit();
}

function setupProto (end,proto) {
  protocol = proto;
  end();
}

function setupService (end,service) {
  svc = service;
  end();
}

function invalidArgument (arg,value_missing) {  
  console.log('Error: the argument %s %s', arg, (value_missing?'expects a value':'is not valid'));
}

function main () {
  try {
    var mdns = require('mdns');
  } catch(err) {
    console.log('Error: missing mdns module');
    console.log('install via: npm install mdns');
    process.exit(1);
  }
  var browser = mdns.createBrowser(svc,proto);
  browser.on('serviceUp', function(info,flags){
    //util.puts('Found: ' + util.inspect(info));
    util.puts('Found: ' + info.name + ' - ' + svc + '://' + info.hosttarget + ':' + info.port);
  });
  browser.on('serviceDown', function(info,flags){
    //util.puts('Leaving: ' + util.inspect(info));
    util.puts('Leaving: ' + info.name + ' - ' + svc + '://' + info.hosttarget + ':' + info.port);
  });
  browser.start();
  
  setTimeout(function(){
    browser.stop();
  },5000);
}