title: Send commands to a GNU screen
body: <p>I have a GNU screen named demo, I want to send commands to it. How do I do this?</p>
  
  <pre><code>screen -S demo -X /home/aa/scripts/outputs.sh
  </code></pre>
  
  <p>yeilds <code>No screen session found.</code></p>
  
  <p>and doing <code>screen -ls</code> shows that it isn't running. </p>