title: Which POSIX flavor of regex does Perl use?
body: <p>Specifically, I'm using the Linux command:</p>
  
  <pre>$ find . -regextype posix-extended -regex '&lt;some regex>' ...</pre>
  
  <p>I just want to make sure the POSIX type I'm using is the type Perl uses, since that is by far the one I am most familiar with.</p>