title: delimiter inside reqular expression Awk
body: <p>I have a term like <code>aa-and-bb</code> in the 10th column of a tab limited file, <code>file.tsv</code>.</p>
  
  <p>I can get <code>aa-and-bb</code> as</p>
  
  <pre><code>cat file.tsv | awk 'BEGIN{FS="\t"};{print $10}'
  </code></pre>
  
  <p>How do I further get <code>aa</code> from <code>aa-and-bb</code>?</p>