login — Login to a command-line session.
login [<string>]
Changes a command-line session to the logged-in state, subject to the correct credentials being supplied. The login process occurs automatically at the start of a new telnet connection, but if no username is entered (i.e. the user just presses Enter), or the login fails, the command-line session stays active but in the logged-out state.
In the logged-out state, only the following four commands are available :-
exit login [<string>] logout quit
Thus, the login command can be used to login when in this logged-out (but connected) state. If the optional argument is supplied, it specifies the username, and no username prompt is printed. The login command can also be used to log-in as a different user without logging out first.