Being using watch (8) utility in FreeBSD I have never knew it's analogue for Linux. When facing such a need I always managed to find another ways to meet it. Just yesterday I had much alike case :) and finally I've found what I needed all this time. Well, there are plenty of them actually :). I have found snoop, ttysnoop (haven't found web site, but there are a lot of prebuilt packages in the web) and ttyrpld.
Though the most watch-like of them seem to be snoop, other also may be worth trying. I have yet tried nothing of them, so comments are appreciated.
And before the end I would mention well-known screen.
