http request charm progress

http-charm.js

var charm = require('charm')(),
    http = require('http');

charm.pipe(process.stdout);
charm.write('\n');
charm.cursor(false);

var options = {
  hostname: 'nodejs.org',
  port: 80,
  path: '/dist/v0.10.13/node-v0.10.13.tar.gz',
  method: 'GET'
};

var req = http.request(options);
req.on('response', function(res){
  var length = res.headers['content-length'],
      count = 0,
      prev = '';

  res.on('data', function(chunk){
    charm.left(prev.length);
    count += chunk.length;
    prev = count + '/' + length;
    charm.write(prev);
  });

  res.on('end', function(){
    charm.write('\n');
    charm.cursor(true);
  });
});
req.end();