title: How can I add a column to a specific position in a csv file using cat, sed, awk or cut?
body: <p>I've got a csv file with this content:</p>
  
  <pre><code>   col1, col2, col5
      1,    1,    1
      2,    2,    2
      3,    3,    3
      4,    4,    4
  </code></pre>
  
  <p>I need to add a column in the third position of the file with a header but with empty values. </p>
  
  <pre><code>col1, col2, col3, col4
  1,    1,        ,   1
  2,    2,        ,   2
  3,    3,        ,   3
  4,    4,        ,   4
  </code></pre>
  
  <p>Is there any way to do it using one of the Linux commands like cat, sed, awk or cut?</p>
  
  <p>I know that with cut is possible to modify a file by columns cut -d , -f1,2,3  file1 > file2. But it seems does not have an option to add a custom column.</p>
  
  <p>Any help would be much appreciated.</p>