title: Empty or "flush" a file descriptor without read()?
body: <p>(Note: This is <strong>not</strong> a question of how to flush a <code>write()</code>. This is the <em>other end</em> of it, so to speak.)</p>
  
  <p>Is it possible to empty a file descriptor that has data to be read in it <strong>without</strong> having to <code>read()</code> it?  You might not be interested in the data, and reading it all would therefore waste space and cycles you might have better uses for.</p>
  
  <p>If it is not possible in POSIX, do any operating systems have any non-portable ways to do this?</p>
  
  <p><strong>UPDATE:</strong> Please note that I'm talking about <em>file descriptors</em>, <strong>not</strong> streams.</p>