title: Reverse sort order of a multicolumn file in BASH
body: <p>I've the following file:</p>
  
  <pre><code>1 2 3
  1 4 5
  1 6 7
  2 3 5
  5 2 1
  </code></pre>
  
  <p>and I want that the file be sorted for the second column but from the largest number (in this case 6) to the smallest. I've tried with</p>
  
  <pre><code>sort +1 -2 file.dat
  </code></pre>
  
  <p>but it gives me the inversed order. </p>
  
  <p>The results should be:</p>
  
  <pre><code>1 6 7
  1 4 5
  2 3 5
  5 2 1
  1 2 3
  </code></pre>