qrcode-gen.js

var fs = require('fs');
var qr = require('qr-image');
var co = require('co');

co(function *() {
  
  for (var index = 1; index <= 100; index++) {
    
    yield function() {
      return function(done) {
        var qr_img = qr.image(index, { type: 'png' });
        var output = fs.createWriteStream('qrcode-' index '.png');
        output.on('finish', function() {
          done();
        });
        
        qr_img.pipe(output);
      };
    }
  }
});