Force logout a user

I When I logged into the machine as root and typed who to see which users are logged in, I found somebody else too logged in as root

devuser   pts/0        2011-11-18 09:55 (xxx.xxx.xxx.xxx)
root      pts/1        2011-11-18 09:56 (xxx.xxx.xxx.xxx)
testuser  pts/2        2011-11-18 14:54 (xxx.xxx.xxx.xxx)
root      pts/3        2011-11-18 14:55 (xxx.xxx.xxx.xxx)

How can I force a root user at pts/3 to logout?

You terminate a session by killing its parent process, called the session leader. Find out which process it is with:

ps -dN|grep pts/3

To kill and logout a user, you can send KILL signal. Type the following command:

# skill -KILL -u vivek

Check these links for more information:

• http://www.cyberciti.biz/tips/howto-linux-kill-and-logout-users.html
• http://www.serverschool.com/server-security/how-to-kill-a-user-session-on-a-linux-server/