Logins-logouts

I want a script that checks the logins and logouts in a system.Is there a way to keep the logins and logouts in files and then compare them every e.g. 10 seconds?
for tcsh.

From the rules:

(4) Do not 'bump up' questions if they are not answered promptly. No duplicate or cross-posting and do not report a post where your goal is to get an answer more quickly.

thread closed.