title: Using linux command "sort -f | uniq -i" together for ignoring case
body: <p>I am trying to find unique and duplicate data in a list of data with two columns.  I really just want to compare the data in column 1.  </p>
  
  <p>The data might look like this (separated by a tab):</p>
  
  <pre><code>What are you doing?     Che cosa stai facendo?
  WHAT ARE YOU DOING?     Che diavolo stai facendo?
  what are you doing?     Qual è il tuo problema amico?
  </code></pre>
  
  <p>So I have been playing around with the following:</p>
  
  <ol>
  <li><p>Sorting without ignoring case <strong>(just "sort", no -f option)</strong> gives me less duplicates</p>
  
  <p>gawk '{ FS = "\t" ; print $1 }' EN-IT_Corpus.txt | <strong>sort</strong>    | uniq -i -D > dupes</p></li>
  <li><p>Sorting with ignoring case <strong>("sort -f")</strong> gives me more duplicates</p>
  
  <p>gawk '{ FS = "\t" ; print $1 }' EN-IT_Corpus.txt | <strong>sort -f</strong> | uniq -i -D > dupes</p></li>
  </ol>
  
  <p>Am I right to think that #2 is more accurate if I want to find duplicates ignoring case, because it sorts it ignoring case first and then finds duplicates based on the sorted data?</p>
  
  <p>As far as I know I can't combine the sort and unique commands because sort doesn't have an option for displaying duplicates.</p>
  
  <p>Thanks, 
  Steve</p>