title: Linux: compute a single hash for a given folder & contents?
body: <p>Surely there must be a way to do this easily! </p>
  
  <p>I've tried the Linux command-line apps such as <code>sha1sum</code> and <code>md5sum</code> but they seem only to be able to compute hashes of individual files and output a list of hash values, one for each file. </p>
  
  <p>I need to generate a single hash for the entire contents of a folder (not just the filenames).</p>
  
  <p>I'd like to do something like</p>
  
  <pre><code>sha1sum /folder/of/stuff &gt; singlehashvalue
  </code></pre>
  
  <p><strong>Edit:</strong> to clarify, my files are at multiple levels in a directory tree, they're not all sitting in the same root folder.</p>