What is the “fastest” way to take a screenshot of a particular window under Linux programmatically?

Question

The language does not matter, the libraries either, I just need the fastest way to specify the window (name or descriptor).

Answer 1

Try:

import // man import for options

Take a snapshot of my pidgin client.

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

You can specify many parameters, such as a frame or window identifier.

Answer 2

see man xwd

xwd takes screenshots

Answer 3

gnome-screenshot.

   gnome-screenshot --help

-w.