title: Changing delimiter of the uniq command
body: <p>I'd like the output of the uniq command to be comma separated, so that instead of:</p>
  
  <pre><code>     30 hello
       31 world
       36 hey_there
      142 i_am_bigest
  </code></pre>
  
  <p>I'll get:</p>
  
  <pre><code>30,hello
  31,world
  36,hey_there
  142,i_am_biggest
  </code></pre>
  
  <p>My input has no spaces, but just using <code>sed</code> or <code>tr</code> can be a problem since the number of leading spaces varies according to the number of decimal digits in the count.</p>