fbgrab(1) on Linux
The text c79af19a4e11, as Debian 10 (Buster), Debian 9 (Stretch) shipped it.
takes a screenshot using the framebuffer device
Flags it lists
-
-? -
-C -
-b -
-c -
-d -
-f -
-h -
-i -
-s -
-w