title: sudo apachectl start not working
body: <p>Before I could use terminal to start Apache service as:</p>
  
  <pre><code>sudo apachectl start
  </code></pre>
  
  <p>But recently it doesn't work, even after I restart my PC. Instead, I can use XAMPP to start Apache easily. Who can tell me why the terminal doesn't work at all? </p>
  
  <p>Besides, since I'm a beginner with command line, I know the statement</p>
  
  <p><code>ps aux | grep httpd</code></p>
  
  <p>can show if apache is running. But I don't know the exact meaning of each field, like:</p>
  
  <pre><code>yy    1708   0.0  0.0  2432772    604 s000  R+    8:05PM   0:00.00 grep httpd
  </code></pre>
  
  <p>what does those numbers or characters mean? Is anyone can help? Thanks!</p>