title: sh: 1: Syntax error: "(" unexpected error
body: <p>I'm executing a script which looks like this.</p>
  
  <pre><code>diff &lt;(grep eth0 /proc/net/dev) &lt;(sleep 1; grep eth0 /proc/net/dev)
  </code></pre>
  
  <p>and I always got the <code>sh: 1: Syntax error: "(" unexpected</code>
  I tried writing it as a .sh file, and tried the different shebang lines.
  I need to create a script that will execute this.</p>