escape from callback hell in node.js

fs_write_read.js

var fs     = require('fs');
var path   = require('path');
var dir    = path.join(__dirname, 'temp');
var source = __filename;
var target = path.join(dir, 'target');

fs.mkdir(dir, handlingError(mkdired));

function mkdired() {
  fs.readFile(source, handlingError(haveFile));
}

function haveFile(content) {
  fs.writeFile(target, content, handlingError(wroteFile));
}

function wroteFile() {
  console.log('all done');
}

function handlingError(callback) {
  return function(err, result) {
    if(err) {
      console.log(err);
    } else {
      callback(result);
    }
  }
}