title: how to escape the < <() idiom in perl
body: <p>I have a system command which i am trying to execute, but it gives me error "Syntax error: redirection unexpected" </p>
  
  <p>Trying command:    </p>
  
  <pre><code>datamash -ft, -g 1 mean 3 mean 4 &lt; &lt;(tail -n +2 yourfile | sort -t, -k1,2) | cut -d, -f1,2,5,6 
  </code></pre>
  
  <p>I tried readpipe and also escaped the &lt; &lt;  with \&lt; \&lt;, but doesn't work.</p>
  
  <p>below command doesn't work ==></p>
  
  <pre><code>`datamash -ft, -g 1 mean 3 mean 4 \&lt; \&lt;(tail -n +2 yourfile | sort -t, -k1,2) | cut -d, -f1,2,5,6`
  </code></pre>