What's the "fastest" way to take a screenshot of a specific window under Linux programatically?

Question

Language doesn't matter, libraries either, I just need the fastest way specifying the window (title or handle).

Answer 1

Try:

import // man import for options

To take a snapshot of my pidgin client.

import -screen -window Kompislista foo.jpg // Kompislista is in swedish.

You can specify a lot of options, such as frame or window id.

Answer 2

see man xwd

xwd takes screen snapshots