Mercurial's only true "plugin" extension: inotify... and can it be done in Git?

[Jakub Narebski <jnareb@gmail.com>]

When reading "Distributed Revision Control with Mercurial"[1] to see
how Mercurial differs from Git, in the chapter 14 "Adding functionality 
with extensions" there is description (in section 14.1) of one 
interesting extension (see also [2]), namely 'inotify' extension. 

This extension[3][4] optimises "hg status" command by asking file 
notification daemon about changed files instead of doing stat. I'm not 
sure how useful this extension is: inotify is Linux specific, and Linux 
has fast stat... nevertheless this is one example where extension 
(plug-in) framework shows that it can do more than good scriptability.

I wonder if, and how, such 'extension' could be done with Git...

References:
===========
[1] http://hgbook.red-bean.com
[2] http://www.selenic.com/mercurial/wiki/index.cgi/UsingExtensions
[3] http://hgbook.red-bean.com/hgbookch14.html#x18-31700014.1
[4] http://www.selenic.com/mercurial/wiki/index.cgi/InotifyExtension
-- 
Jakub Narebski
Poland