Assuming the users have the standard POSIX shell (or perhaps ksh), put this in your /etc/profile file:
export HISTFILE=$HOME/.sh_history
Just to be sure, create the shell history file in every user's directory. Assuming (again) that all users have their HOME in the /home directory, do this one time:
umask 077
export PATH=/usr/bin
for MYHOME in /home/*
do
MYUSER=$(basename $MYHOME)
touch $MYHOME/.sh_history
chown $MYUSER $HOME/.sh_history
done
Note that if the users are doing something complicated like running an Xwindow emulator and using CDE to manage their screens, there are more steps required.
Bill Hassell, sysadmin