title: Why is #!/usr/bin/env bash superior to #!/bin/bash?
body: <p>I've seen in a number of places, including recommendations on this site (<a href="https://stackoverflow.com/questions/10376206/preferred-bash-shebang">What is the preferred Bash shebang?</a>), to use <code>#!/usr/bin/env bash</code> in preference to <code>#!/bin/bash</code>. I've even seen one enterprising individual <a href="http://mywiki.wooledge.org/BashGuide/Practices#Choose_Your_Shell" rel="noreferrer">suggest using <code>#!/bin/bash</code> was <em>wrong</em></a> and bash functionality would be lost by doing so.</p>
  
  <p>All that said, I use bash in a tightly controlled test environment where every drive in circulation is essentially a clone of a single master drive. I understand the portability argument, though it is not necessarily applicable in my case. Is there any other reason to prefer <code>#!/usr/bin/env bash</code>over the alternatives and, assuming portability was a concern, is there any reason using it could break functionality?</p>