FBGRAB: Tomar una screenshot de una TTY

Desde una tty con framebuffer puedes tomar una screenshot con fbgrab es muy facil de usar solo:

[dalfa@MDV2006 ~]$ fbgrab nombre_de_archivo.png

aqui un pequeño corta y pega de la man:

fbgrab(1)                                                            fbgrab(1)

NAME
       fbgrab - takes screenshots using the framebuffer device

SYNOPSIS
       fbgrab [options] filename

DESCRIPTION
       fbgrab  reads  the  framebuffer device (/dev/fb*) or a dump thereof and
       saves a PNG image file. You can use it for  making  screenshots  of  of
       virtually  any  application, from traditional test applications to your
       X-windows desktop, as well as framebuffer applications.

OPTIONS
       -?     print usage information.

       -b bitdepth
              the number of bits per pixel used, optional  when  reading  from
              device.

       -c console
              specifies which console (or virtual terminal - like other people
              call this feature) to grab. Sometimes this  changing  is  faster
              then  the  framebuffer  is  refreshed  (especially when grabbing
              framebuffer apps). If so, you should use  -C  console  ...  This
              waits  some time before grabbing. You can't use -s in this case.

       -d device
              specifies which framebuffer device you want to read. If  you  do
              not  use  this  option,  it takes the value from the FRAMEBUFFER
              environment variable. If no FRAMEBUFFER environment variable  is
              given  or  if  its value is NULL, then DEFAULT_FB is taken. (see
              source code), which usually is /dev/fb0.

       -f filename
              Read from from file instead of device, requires that -w (width),
              -h (height) and -b (bitdepth) are specified.

       -h height
              the  height  of the frambeuffer in pixels, optional when reading
              from device.

       -i     turns off interlacing. If you do not want ADAM7 interlacing, you
              should use the -i option.

       -s seconds
              specifies  how many seconds to wait before grabbing. fbgrab does
              not lock console switching, so you can switch it while  waiting,
              if  you  cannot  use  -c requires normally that fbgrab is run as
              root.

       -w width
 the width of the frambeuffer in pixels,  optional  when  reading
              from device.

EXAMPLES
       fbgrab fb.png

       will take a framebuffer snapshot, or if you don't have fbgrab  at  your
       machine, you can do

       cp /dev/fb0 framebuffer.dump

       and then

       fbgrab -w 1024 -h 768 -b 16 -f framebuffer.dump fb.png

       to convert it to a picture.