title: How to find the options in if conditions of shell
body: <p>In one of my shell script, I'm seeing</p>
  
  <pre><code>if [[ ! -d directory1 || ! -L directory ]] ; then
  </code></pre>
  
  <p>What does <code>-d</code> and <code>-L</code> option mean here? Where can I find information about the options to use in an <code>if</code> condition?</p>