iostream2.js

var path = require('path'),
    fs = require('fs');

var outputFilePath = path.join(__dirname, 'write.txt');
var writeStream = fs.createWriteStream(outputFilePath);

var inputFilePath = path.join(__dirname, 'test.txt');
var readStream = fs.createReadStream(inputFilePath);

writeStream.on('pipe', function(){
  console.log('a readableStream pipes writeStream');
});
writeStream.on('error', function(err){
  console.log('An error occured');
  console.log(err);
});
writeStream.on('close', function(){
  console.log('writable stream closed');
});

readStream.pipe(writeStream);

readStream.on('data', function(data){
  console.log('>> a data event occured.');
});
readStream.on('end', function(){
  console.log('read end');
});
readStream.on('error', function(err){
  console.log('An error occured');
  console.log(err);
});