11/3/71 LOGIN, LOGOUT (VII)
NAME logging in and logging out
SYNOPSIS --
DESCRIPTION UNIX must be called from an appropriate terminal.
The two general classes of terminals which UNIX
supports are typified by the 37 Teletype on the
one hand and the GE TermiNet 300 and Memorex 1240
on the other. The principal difference is the
baud rate (150 vs. 300) and the treatment of the
carriage return character. Most terminals oper-
ating at 150, 300, or 1200 baud using the ASCII
character set either work (more or less) at the
moment or can be used by special arragement. In
particular, special arrangement is necessary for
terminals which do not generate lower-case ASCII
characters
It is also necessary to have a valid UNIX user ID
and (if desired) password. These may be ob-
tained, together with the telephone number, from
the system administrators.
The same telephone number serves terminals oper-
ating at both the standard speeds. When a con-
nection is established via a 150-baud terminal
(e.g. TTY 37) UNIX types out "login:"; you re-
spond with your user name, and, if a mask is
typed, with a password. If the login was suc-
cessful, the "@" character is typed by the Shell
to indicate login is complete and commands may be
issued. A message of the day may be typed if
there are any announcements. Also, if there is a
file called "mailbox", you are notified that
someone has sent you mail. (See the mail com-
mand.)
From a 300-baud terminal, the procedure is
slightly different. Such terminals often have a
full-duplex switch, which should be turned on (or
conversely, half-duplex should be turned off).
When a connection with UNIX is established, a few
garbage characters are typed (these are the "lo-
gin:" message at the wrong speed). You should
depress the "break" key; this is a speed-
independent signal to UNIX that a 300-baud termi-
nal is in use. It will type "login:" (at the
correct speed this time) and from then on the
procedure is the same as described above.
Logging out is simple by comparison (in fact,
sometimes too simple). Simply generate an end-
of-file at Shell level by using the EOT charac-
ter; the "login:" message will appear again to
indicate that you may log in again.
It is also possible to log out simply by hanging
up the terminal; this simulates an end-of-file on
the typewriter.
FILES --
SEE ALSO init
DIAGNOSTICS --
BUGS Hanging up on programs which never read the type-
writer or which ignore end-of-files is very dan-
gerous; in the worst cases, the programs can only
be halted by restarting the system.
OWNER ken, dmr