What is the best way to play chess via terminal? I've recently learned about gnu chess, but it's poorly documented, and I'm having difficulties:


Setting a reasonable difficulty level;
Saving an entire game to a pgn: it's only saving the last move;


How can I do this?
Is there an e-book or a good tutorial I can follow?

Thanks in advance

Update (2/8/15):  Actually,  it's the version of gnuchess that's packaged with Debian 7 (6.0.2) that has a bug; after compiling 6.2.1 pgnsave worked normally.
You can save games with:

pgnsave FILENAME


This saves the game played so far from memory to a file. 

You can find some documentation here: http://savannah.gnu.org/projects/chess/