title: Perl code - pipe "|" in `open()` statement
body: <p>I have the following code in a Perl .pl file. Do you think there's any issue with this code (I can't understand how it'll work as in the 2nd line there's a "|" character without a command following it)</p>
  
  <pre><code>while ( $temp ne "" ) {
          open( PS, "ps -ef | grep deploy.sh | grep ssh | grep -v grep|" );
          $temp = &lt;PS&gt;;
          close(PS);
          print "The Deploy scripts are still running.  Now sleeping 20\n";
          sleep 20;
  }
  </code></pre>