LOGIN(1)LOGIN(1)NAMElogin - sign on
SYNOPSISlogin [ -p ] [ username ]
DESCRIPTION
The login command is used when a user initially signs on, or it may be
used at any time to change from one user to another. The latter case
is the one summarized above and described here. See “How to Get
Started” for how to dial up initially.
If login is invoked without an argument, it asks for a user name, and,
if appropriate, a password. Echoing is turned off (if possible) during
the typing of the password, so it will not appear on the written record
of the session.
After a successful login, accounting files are updated and the user is
informed of the existence of mail. The message of the day is printed,
as is the time of his last login. Both are suppressed if he has a
“.hushlogin” file in his home directory; this is mostly used to make
life easier for non-human users, such as uucp.
Login initializes the user and group IDs and the working directory,
then executes a command interpreter (usually csh(1)) according to
specifications found in a password file. Argument 0 of the command
interpreter is the name of the command interpreter with a leading dash
(“-”).
Login also modifies the environment environ(7) with information
specifying home directory, command interpreter, terminal type (if
available) and user name. The `-p' argument causes the remainder of
the environment to be preserved, otherwise any previous environment is
discarded.
If the file /etc/nologin exists, login prints its contents on the
user's terminal and exits. This is used by shutdown(8) to stop users
logging in when the system is about to go down.
Login is recognized by sh(1) and csh(1) and executed directly (without
forking).
FILES
/etc/utmp accounting
/usr/adm/wtmp accounting
/usr/spool/mail/* mail
/etc/motd message-of-the-day
/etc/passwd password file
/etc/nologin stops logins
.hushlogin makes login quieter
SEE ALSOinit(8), getty(8), mail(1), passwd(1), passwd(5), environ(7),
shutdown(8), rlogin(1c)DIAGNOSTICS
“Login incorrect,” if the name or the password is bad.
“No Shell”, “cannot open password file”, “no directory”: consult a
programming counselor.
BUGS-h is used by telnetd(8C) and other servers to list the host from which
the connection was received.
4th Berkeley Distribution May 8, 1986 LOGIN(1)