title: Using ls to list directories and their total sizes
body: <p>Is it possible to use <code>ls</code> in Unix to list the total size of a sub-directory and all its contents as opposed to the usual <code>4K</code> that (I assume) is just the directory file itself?</p>
  
  <pre><code>total 12K
  drwxrwxr-x  6 *** *** 4.0K 2009-06-19 10:10 branches
  drwxrwxr-x 13 *** *** 4.0K 2009-06-19 10:52 tags
  drwxrwxr-x 16 *** *** 4.0K 2009-06-19 10:02 trunk
  </code></pre>
  
  <p>After scouring the man pages I'm coming up empty.</p>