Macos – Mac Screenshot of a Specific Window without Using the Mouse/Click

Just tested with import and a window extended beyond / bigger than the screen size; and it seems import will capture an image of the same size as the big window size -- unfortunately all pixels beyond the screen size, and all pixels covered by other windows, will be black.

So maybe the only way is to use xrandr to enlarge screen size (as in 'screen pannning') - or to use something else that will provide larger screen size: for instance, "How can I take browser screenshots at a higher resolution than my browser supports? - Super User" notes:

Use Xephyr to create a nested X session

(Xephyr is apparently in sudo apt-get install xserver-xephyr in Ubuntu)

Hope this helps,
Cheers!

Edit: yup, xrandr works with the usual printscreen for me (also with import, just needs enough space for a terminal to fit, so it doesn't overlap the target window), just note the Virtual size in xorg.conf (see "xrandr: screen cannot be larger than" ...)

Open Automator, choose Application, add a Run Shell Script action and put in your Shell command between quotes (if you have a file, you can just drag and drop it).

Other than playing it, now you can save it (as an app anywhere) and even set the icon.