User name is utmost important in Linux operating system. Unlike Windows operating system series of consumer oriented OS which sometimes allows single user to automatically log on to desktop without prompting for user name and password, Linux doesn’t come with this convenient (KDE apparently can). Each user must type his or her own user name and password before able to login into shell or desktop.
If you feel that your user name is not attractive enough, or boring or your taste and experience has changed since the user name was first created, use the following command to change the user name in Linux.
usermod -l <new login name> <old login name>
Replace new login name with the new user name you want to use in future, and old login name with the existing username to change.
For NIS accounts, additional commands is required to maintain a proper copy of user account across computer network. Run the following commands:
cd /var/yp make