title: Pipe out a substring by removing the last N characters
body: <p>How can I pipe a string and drop a few characters off it?, e.g:</p>
  
  <pre><code>$ echo forbes | ... -3
  for
  $ echo cucumber | ... -4
  cucu
  $ echo 1461624333 | .. -3 
  1461624
  ...
  etc.
  </code></pre>
  
  <p>I couldn't find way to use <code>${str:0:-3}</code> syntax in a pipe.</p>