title: Find and replace text in files in all subdirectories
body: <p>On a Mac; I'm using Hazel to run a shell script, in order to find &amp; replace text in <code>.txt</code> files in multiple subdirectories inside my Downloads folder.
  My script.sh file lives somewhere else (<code>/Users/admin/Desktop</code>)</p>
  
  <p><code>script.sh</code> looks like this currently:</p>
  
  <pre><code>#!/bin/bash
  cd /Users/admin/Downloads/
  perl -pi -w -e 's/OldText/NewText/g;' *.txt
  </code></pre>
  
  <p>It works, but doesn't look through all the subdirectories inside Downloads. How do I do that?</p>