title: Restart nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
body: <p>I try to <code>sudo service nginx restart</code> and it shows this error:</p>
  
  <pre><code>nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
  </code></pre>
  
  <p>I think it is about this symlink?</p>
  
  <pre><code>ln -s ../sites-available/default default
  </code></pre>
  
  <p>I try</p>
  
  <pre><code>cd /etc/nginx &amp;&amp; grep -R listen *
  
  sites-available/default:        listen 80;
  sites-enabled/default:        listen 80;
  </code></pre>
  
  <p>How do I fix it?</p>