On Sun, 15 Sep 2013 01:12:30 +1100, Dmitry Kolesov said:

> I want to catch plug/unplug events of headphone.
> Could anybody explain where I need to search?

If you explained a bit more what you're trying to do, we'd be able to
give better advice.

Are you trying to catch them from userspace, or inside the kernel?  And
what do you want to do once you catch the event?