title: How to specify *one* tab as field separator in AWK?
body: <p>The default for white-space field separators, such as tab when using <code>FS = "\t"</code>, in <code>AWK</code> is either one or many. Therefore, if you want to read in a tab separated file with null values in some columns (other than the last), it skips over them. For example:</p>
  
  <pre><code>1 "\t" 2 "\t" "" "\t" 4 "\t" 5
  </code></pre>
  
  <p><code>$3</code> would refer to <code>4</code>, not the null <code>""</code> even though there are clearly two tabs.</p>
  
  <p>What should I do so that I can specify the field separator to be one tab only, so that <code>$4</code> would refer to <code>4</code> and not <code>5</code>?</p>