title: how do I make node child_process exec continuously
body: <p>How to <code>exec</code> continuously? e.g. <code>ls</code> after <code>cd</code>?</p>
  
  <p>I tried</p>
  
  <pre><code>exec = require('child_process').exec;
  exec('cd ~/', 
    function(){
      exec('ls'),
      function(err, stdout, stderr){
        console.log(stdout); // this logs current dir but not ~/'s
      }
    }
  )
  
  exec('cd ~/').exec('ls', function(err, stdout, stderr){
    console.log(stdout);
  })//this also fails because first exec returns a ChildProcess Object but not itself.
  </code></pre>