suppose more than one person is logging as a particular user.say i logged in as the user "user1" , if another user loggs in later as my user name "user1" when i am still on line ; is there any method my which i get a prompt on my scrren saying that "user1 has logged in on terminal /dev/pts/x from machine 192.168.5.4" or something of a similar kind.. so that i dont ned to keep pressing who -u always.. (also please suggest anything other that a shell script the does "who -u" and uses a grep/awk/sed etc to find out and prompt to my screen :-( )

You could prevent it by choosing a strong password.

Well its not like the other users who are logging in are unauthorised users.. we just want to know which one of us logged in(instantaneously) when the other is using the system...

Why is there more than one user using the account? That eliminates accountability (no pun intended). Unless you do some type of automated behavioral biometrics (or whatever), there really is no way for you to be sure that when you get the notification it isn't an unauthorized user. Also, why don't you wanna do this with a shell script? It would seem to me like the most straight-forward way to do it, considering you've been doing okay by manually typing the commands and parsing the output in your head. Are you looking for some kind of GUI notification instead?

keep the command "echo message you wanted to print" in ~/.bashrc

It sounds like you are sharing an account instead of using a group and adding users to the group.

the thing is that we are using some liscenced software that has lisense for only the one user account, but more than one developer is using that software :-).. and we all do have to login as the same user.. plus i am just a junior here so for all i like i cant add new users to the group to use it ; nor even suggest it to my uptight boss. :-(

yeah the bashrc thing sure helps.. (damn how could i even miss that!!!)