title: Regular Expression to Match List of File Extensions
body: <p>I would like to have a regular expression that will match a list of file extensions that are delimited with a pipe <code>|</code> such as <code>doc|xls|pdf</code>  This list could also just be a single extension such as <code>pdf</code> or it could also be a wild card <code>*</code> or <code>?</code>  I would also like to exclude the <code>|</code> at the start or the end of the list and also not match the <code>\&lt;&gt;/:&quot;</code> characters.</p>
  <p>I have tried the following but it doesn't account for a single <code>*</code> wildcard.</p>
  <p><code>^([^|\\&lt;&gt;\/:&quot;]|[^\\&lt;&gt;:&quot;])[^\/\\&lt;&gt;:&quot;]*[^|\/\\&lt;&gt;:&quot;]$</code></p>
  <p>I have been on one of the online testers but can't seem to get over the final hurdle.  If someone could point me in the right direction I would be most grateful.</p>