title: pass stdout as file name for command line util?
body: <p>I'm working with a command line utility that requires passing the name of a file to write output to, e.g.</p>
  
  <pre><code>foo -o output.txt
  </code></pre>
  
  <p>The only thing it writes to <code>stdout</code> is a message that indicates that it ran successfully.  I'd like to be able to pipe everything that is written to <code>output.txt</code> to another command line utility.  My motivation is that output.txt will end up being a 40 GB file that I don't need to keep, and I'd rather pipe the streams than work on massive files in a stepwise manner.  </p>
  
  <p>Is there any way in this scenario to pipe the real output (i.e. <code>output.txt</code>) to another command?  Can I somehow magically pass <code>stdout</code> as the file argument?</p>