Taking a screenshot (within X)
The most commonly used Linux application for taking screen-shots is called scrot
You can install it with for Debian:
sudo apt-get install scrot
Or for Arch:
sudo pacman -S scrot
A screenshot is taken by typing:
scrot output-file.png
If you want to bind scrot
to the print screen
key then that will need to be controlled by your window manager.
I found a great answer to this question here, it is worth repeating.
This can be achieved with ImageMagick. Install by running the command
sudo apt-get install imagemagick
To grab all desktop just type
import -window root screen.png
Or you can do it with a delay of 5 seconds
sleep 5; import -window root screen.png