title: What's the difference between [ and [[ in Bash?
body: <p>I looked at bash man page and the <code>[[</code> says it uses Conditional Expressions. Then I looked at Conditional Expressions section and it lists the same operators as <code>test</code> (and <code>[</code>).</p>
  
  <p>So I wonder, what is the difference between <code>[</code> and <code>[[</code> in Bash?</p>