title: starting apachectl from bash
body: <p>I am writing a bash file. I need to start <em><code>apachectl</code></em> from my bash file. so i wrote:</p>
  
  <pre><code>apachectl start
  </code></pre>
  
  <p>When I run it with root, an error occurred:</p>
  
  <pre><code>apachectl: command not found
  </code></pre>
  
  <p>I searched and I found that, I should be <em>super user</em> with <code>su -</code> not <code>su</code></p>
  
  <p>Now, I want to know:</p>
  
  <ul>
  <li><p>why this error occurred?</p></li>
  <li><p>How could i run it with <code>su</code>?</p></li>
  </ul>