title: Fastest way to sort files
body: <p>I have a huge text file with lines like:</p>
  
  <pre><code>-568.563626  159   33  -1109.660591  -1231.295129  4.381508
  -541.181308  159   28  -1019.279615  -1059.115975  4.632301
  -535.370812  155   29  -1033.071786  -1152.907805  4.420473
  -533.547101  157   28  -1046.218277  -1063.389677  4.423696
  </code></pre>
  
  <p>What I want is to sort the file, depending on the 5th column, so I would get</p>
  
  <pre><code>-568.563626  159   33  -1109.660591  -1231.295129  4.381508
  -535.370812  155   29  -1033.071786  -1152.907805  4.420473
  -533.547101  157   28  -1046.218277  -1063.389677  4.423696
  -541.181308  159   28  -1019.279615  -1059.115975  4.632301
  </code></pre>
  
  <p>For this I use:</p>
  
  <p><code>for i in file.txt ; do sort -k5n $i ; done</code></p>
  
  <p>I wonder if this is the fastest or more efficient way</p>
  
  <p>Thanks</p>