Async to sync

Without modules for any asynchronous functions:

step1();

function step1 () {
  exec('COMMAND', onStep1Ready);
}

function onStep1Ready () {
  //handling results
  step2();
}

function step2() {
  exec('COMMAND', onStep2Ready);
}

function onStep2Ready () {
  //handling results
  step3();
}

//... and so on

function finish () {
  // display results
}