(Windows) Update Node.js (64-bit version) (No download if versions match)

update-node.js

var http = require('http');
var fs = require('fs');
var child_process = require('child_process');

var pageUrl = "http://nodejs.org/download/";
var downloadUrlRegex = /http:\/\/nodejs\.org\/dist\/v[0-9\.]+\/x64\/node-(v[0-9\.]+)-x64\.msi/i;
var downloadUrl;
var downloadVersion;
var pageSource;
var filePath = "node.msi";
var nodeVersion;

child_process.exec("node -v", function (err, stdout) {
  nodeVersion = stdout.trim();
  
  var pageReq = http.get(pageUrl, function (res) {
    res.setEncoding("utf8");
    res.on("data", function (chunk) {
      pageSource += chunk;
    });

    res.on("end", function () {
      var match = pageSource.match(downloadUrlRegex);
      downloadUrl = match[0];
      downloadVersion = match[1];
      
      if (nodeVersion === downloadVersion) return;
      
      var file = fs.createWriteStream(filePath);
      http.get(downloadUrl, function (res) {
        res.pipe(file);
        file.on('finish', function() {
          file.close();
          child_process.exec(filePath + " /quiet", function() {
            fs.unlinkSync(filePath);
          });
        });
      });
    });
  });
});