title: try to kill all nodes but failed on osx
body: <p>I hope to restart nodejs on mac osx</p>
  
  <pre><code>$ps aux | grep node
  mymac      20215   0.0  0.0  2432768    460 s000  R+    9:49AM   0:00.00 grep node
  </code></pre>
  
  <p>there is one PID 20215, I try to kill the process</p>
  
  <pre><code>kill -2 20215
  </code></pre>
  
  <p>it reports </p>
  
  <pre><code>-bash: kill: (20215) - No such process
  </code></pre>
  
  <p>your comment welcome</p>