title: Put a comma in a specific column
body: <p>I would like to know how to put a comma in one column (space). For example.</p>
  
  <pre><code>a b c d e
  </code></pre>
  
  <p>And I would like this.</p>
  
  <pre><code>a b c d, e
  </code></pre>
  
  <p>A comma in the 4th space.</p>
  
  <p>I tried with this command.</p>
  
  <pre><code>awk -F '{print $4}' &lt; file.txt | cut -d"," -f4-
  </code></pre>