title: bash double bracket issue
body: <p>I'm very new to bash scripting and am running into an issue when using double brackets. I can't seem to get them to work at all in Ubuntu Server 11.10. My script below is in if_test.sh. </p>
  
  <pre><code>#!/bin/bash
  
  if [[ "14"=="14" ]]; then 
      echo "FOO"
  fi
  </code></pre>
  
  <p>When I run this simple shell script the output I get is: if_test.sh: 5: [[: not found</p>
  
  <p>It seems that I'm running GNU bash version 4.2.10 after running bash --version from the terminal. Any help would be greatly appreciated. Thanks!</p>