Quite often there's a need for you to take a screenshot of your Unix desktop, and as always there's a number of ways to do it. Today I'm going to cover the command line approach to taking screenshots.
Taking a Screenshot with xwd
Most modern Unix desktop systems come with Gnome desktop environment by default, and use Xorg as their default X11 server. This means you are likely to have the xwd tool in your OS, which allows you to take screenshots.
Furthermore, many Unix distros come with hundreds of command-line tools bundled with the default OS install. Imagemagick is one of such bundled toolkits, and you can use the convert tool which is part of it for converting the xwd-generated screenshot into any graphics format of your preference.
Here's how you use these two commands together:
bash-3.0$ xwd -root | convert - /tmp/screenshot.png
In this line, xwd command is invoked to take a full screenshot of your desktop. You then pipe its output to the convert tool and specify where you want this output saved to.