It&#x27;s not terribly portable, but you can use extended file attributes.<p>Here&#x27;s an article showing how they work for Linux, OSX, and FreeBSD: <a href="http:&#x2F;&#x2F;www.lesbonscomptes.com&#x2F;pages&#x2F;extattrs.html" rel="nofollow">http:&#x2F;&#x2F;www.lesbonscomptes.com&#x2F;pages&#x2F;extattrs.html</a>