quoted

Will Inotify help?

http://en.wikipedia.org/wiki/Inotify
http://www.kernel.org/doc/man-pages/online/pages/man7/inotify.7.html

It is pretty much what I want to do, the problem with it is that it doesn't
appear to be recursive.  

I looked again tonight, and it appears that newer kernels with fanotify are
able to do this.  So the feature is available, just too new to be on my
servers.  Oh, well :P

Thanks for the input.  I will probably just end up doing what I can with
ld_preload.

Chris