title: How to sort a file, based on its numerical values for a field?
body: <p>Example <code>file.txt</code>:</p>
  
  <pre><code>  100 foo
    2 bar
    300 tuu
  </code></pre>
  
  <p>When using <code>sort -k 1,1 file.txt</code>, the order of lines will not change, though we are expecting :</p>
  
  <pre><code>  2 bar
    100 foo
    300 tuu
  </code></pre>
  
  <p>How to sort a field consisting of numbers based on the absolute numerical value?</p>