title: How to make "if not true condition"?
body: <p>I would like to have the <code>echo</code> command executed when <code>cat /etc/passwd | grep "sysa"</code> is not true.</p>
  
  <p>What am I doing wrong?</p>
  
  <pre><code>if ! [ $(cat /etc/passwd | grep "sysa") ]; then
          echo "ERROR - The user sysa could not be looked up"
          exit 2
  fi
  </code></pre>