Taking screenshot of GNU/Linux tty (virtual terminal, teletype) needs different kind of tool. If in the X11 environment we depend on X11 and another stuffs, such as using GNOME Screenshot, in the pure tty we can not depend to X11 or another display server. We can use a free software tool like fbcat to take tty screenshots.
To take a screenshot, first enter any tty you have (Ctrl+Alt+F1 until Ctrl+Alt+F6). Then perform fbcat command. Here is a command example.
sudo fbcat > tty4.ppmThis command will create a file named tty4.ppm in the same directory with the tty prompt (in the $HOME directory by default). This PPM file is usually huge (about 3 MB in our example). You may convert it to PNG or JPEG by another tool such as Gwenview or GNOME Image Viewer. The result is something like this:
To go back to the GUI, press Ctrl+Alt+F7.