setterm -dump N will dump the contents of the
screen of /dev/ttyN to a file
screen.dump in the current directory. See
setterm(1).
The current contents of the screen of
/dev/ttyN can be accessed using the device
/dev/vcsN (where `vcs' stands for `virtual
console screen'). For example, you could have a clock program
that displays the current time in the upper right hand corner of
the console screen (see the program vcstime in
kbd-1.04.tar.gz). Just dumping the contents goes
with cat /dev/vcsN. These device files
/dev/vcsN do not contain newlines, and do not
contain attributes, like colors. From a program it is usually
better to use /dev/vcsaN (`virtual console
screen with attributes') instead - it starts with a header giving
the number of rows and columns and the location of the cursor.
See vcs(4).