title: How can I print the total number of file descriptors with index 24
body: <p>How can I print the total number of file descriptors with index 24 for all the running processes?</p>
  
  <p>I tried something: $ </p>
  
  <pre><code>ls /proc/*/fd 2&gt; errors.txt &gt; stdout.txt | grep "^24" stdout.txt | wc -l
  </code></pre>
  
  <p>This solution returns 0 everytime.</p>
  
  <p>I mention that my task ask me to write an one liner in order to solve it.</p>