gistfile1.js

var fs = require('fs');

// Start with a binary file
fs.readFile('foo.jpg', function(err, data){
  // Write as base64 encoded text
  fs.writeFile('foo.txt', data.toString('base64'), function(err){
    // Read the base64 encoded file back in.
    fs.readFile('foo.txt', function(err, data){
      // Write back out as binary data
      fs.writeFile('bar.jpg', data, 'base64', function(err){
        // Yet bar.jpg === foo.txt instead of bar.jpg === foo.jpg
      })
    })
  })
});