Download any track on youtube from cmd

hiphop.js

var request = require('request');
var prompt = require('prompt');
var fs = require('fs');
var ytdl = require('ytdl');
var flv = require('flv');
require('colors');
var shortId = require('shortid');
var request = require('request');
var progress = require('request-progress');
var ProgressBar = require('progress');


//
// Start the prompt
//
prompt.start();
prompt.get(["query"], function (err, prompted) {
   request({
      url: "http://itunes.apple.com/search?media=music&entity=song&limit=10&term=" + encodeURIComponent(prompted.query),
      json: true
   }, function (dataAndEvents, r, data) {
      for (var result in data.results) {
         console.log(result, ": ", data.results[result].trackName, " - ", data.results[result].artistName);
      }

      prompt.get(["track"], function (err, prompted) {
         var trackName = data.results[prompted.track - 0].trackName + " - " + data.results[prompted.track - 0].artistName;
         console.log(trackName);
         request({
            url: "http://gdata.youtube.com/feeds/api/videos?alt=json&max-results=1&q=" + encodeURIComponent(trackName),
            json: true
         }, function (dataAndEvents, deepDataAndEvents, data) {
            var url = data.feed.entry[0].link[0].href;
            console.log(data.feed.entry[0].link[0].href);
            console.log("=> Downloading video...");

            var fileName = shortId.generate();

            ytdl.getInfo(data.feed.entry[0].link[0].href, {
               downloadURL: true
            }, function (err, info) {
               info.formats = info.formats.filter(function (el) {
                  return el.container === "flv";
               }).sort(function (a, b) {
                  if (a.audioBitrate && b.audioBitrate) {
                     if (a.audioBitrate > b.audioBitrate)
                        return -1;
                     else
                        return 1;
                  }
                  if (a.resolution && b.resolution) {
                     if (/(\d+)p/.exec(a.resolution)[1] > /(\d+)p/.exec(b.resolution)[1])
                        return -1;
                     else
                        return 1;
                  }
                  return 0;
               });
               var url = info.formats[0].url;
               console.log();
               var bar = new ProgressBar('  downloading [:bar] :percent :etas', {
                  complete: '=',
                  incomplete: ' ',
                  width: 20,
                  total: 100
               });
               // Note that the options argument is optional
               progress(request(url), {})
                  .on('progress', function (state) {
                     if (!bar.complete)
                        bar.tick(state.percent);
                  })
                  .on('error', function (err) {
                     throw err;
                  })
                  .pipe(fs.createWriteStream(fileName))
                  .on('error', function (err) {
                     throw err;
                  })
                  .on('close', function (err) {
                     console.log('\ncomplete\n');
                     process.stdout.write("=> Done".green + "\r");
                     console.log("=> Starting conversion to mp3...");
                     // create a readable stream to some FLV file
                     var file = fs.createReadStream(fileName);

                     var decoder = new flv.Decoder();

                     decoder.on('audio', function (audio) {
                        // "audio" is a Readable stream of audio data
                        // the type of audio data depends on the FLV file, could be AAC, MP3, etc.
                        audio.pipe(fs.createWriteStream(trackName.replace(/["\/\\']/g, "") + ".mp3")).on('close', function () {
                           console.log('  > MP3 extracted');
                           fs.unlinkSync(fileName);
                           console.log('=> Done'.green);
                        });
                     });

                     file.pipe(decoder).on('close', function () {
                        console.log('  > FLV Video loaded');
                     });
                  });
            });


         });
      });
   });
});

Inspired from late HipHopApp