Completely rewrote split_tac. The old one failed in strange circumstances.
#! /bin/sh
# xlisten -- start a program in one window and create a listener window
# environment variable $LISTEN specifies the file name
#create the file!
date > $LISTEN
xterm -geo 80x10+0+0 -T Listener -n Listener -e tail -f $LISTEN &
sleep 2
xterm -geo 80x45+0-0 -e teeinput $* &