My Raspberry Pi now has both a 7″ touchscreen and a 24″ monitor working at the same time. Most work is done on the big screen but the smaller display is for testing. I’ve reconfigured it so the menu is on the bigger screen, it makes more sense.
For quick and dirty screen shots, I use scrot (the name is derived from SCReenshOT). I’m fairly certain this was included with the operating system as it was installed, it wasn’t anything I added. What I didn’t expect was that it would capture both screens and put them in the one image. It fills the gap with a copy of the smaller screen.
Scrot is fine for most stuff but I thought that if I wanted to capture things like menus then I was going to install another utility that offered a time delay but digging a bit deeper, it turns out that scrot can do that as well. As with most Linux programs,
Gives you a list of commands and there’s a -d (or –delay) NUM which pauses NUM seconds before doing the grab. Other options let you do a countdown (-c), capture with border (-b) and you can even have it run another program (-e) on the screenshot. Handy if you had it running unattended on a cron job and wanted to email the grab.
There’s a bit more but I’ll leave that for you to investigate.