title: Remove odd or even lines from a text file
body: <p>I need to remove odd lines in a text file to make a down-sampling. I've found this command,</p>
  
  <pre><code>awk 'NR%2==0' file
  </code></pre>
  
  <p>but it only prints the odd lines in the terminal. How to really remove them?</p>
  
  <p>I don't really care for even or odd, I want them removed from the file or printed in another file. This only prints them in the terminal.</p>