code: function ScanGpxDir (gpxdir) {
      var availableRoutes=[];
      var count=0;
      var routesDir = gpxdir;
      var directory = fs.readdirSync(routesDir);
      for (var i in directory) {
          var file = directory [i];
          var route  = path.basename (directory [i],".gpx");
          var name = routesDir + route + '.gpx';
          try {
              if (fs.statSync(name).isFile()) {
                  count ++;
                  availableRoutes [route] = name;
                  console.log ("Found Gpx Route: " + route + " file: " + availableRoutes [route]);
              }
          } catch (err) {/* ignore errors */}
      }
      if (count < 3) {
          console.log ("Find only [%d] GPX file in [%s] please check your directory", count, parsing.opts.gpxdir);
          process.exit (-1);
      }
      return (availableRoutes);
  }
docs: scan directory and extract all .gpx files