login(1) BSD General Commands Manual login(1)
NAME
login -- log into the computer
SYNOPSIS
login [-pq] [-h hostname] [user]
login -f [-lpq] [-h hostname] [user [prog [args...]]]
DESCRIPTION
The login utility logs users (and pseudo-users) into the computer system.
If no user is specified, or if a user is specified and authentication of
the user fails, login prompts for a user name. Authentication of users
is done via passwords.
The options are as follows:
-f The -f option is used when a user name is specified to indicate
that proper authentication has already been done and that no
password need be requested. This option may only be used by the
super-user or when an already logged in user is logging in as
themselves.
With the -f option, an alternate program (and any arguments) may
be run instead of the user's default shell. The program and
arguments follows the user name.
-h The -h option specifies the host from which the connection was
received. It is used by various daemons such as telnetd(8).
This option may only be used by the super-user.
-l Tells the program executed by login that this is not a login ses-
sion (by convention, a login session is signalled to the program
with a hyphen as the first character of argv[0]; this option dis-
ables that), and prevents it from chdir(2)ing to the user's home
directory. The default is to add the hyphen (this is a login
session).
-p By default, login discards any previous environment. The -p
option disables this behavior.
-q This forces quiet logins, as if a .hushlogin is present.
If the file /etc/nologin exists, login dislays its contents to the user
and exits. This is used by shutdown(8) to prevent users from logging in
when the system is about to go down.
Immediately after logging a user in, login displays the system copyright
notice, the date and time the user last logged in, the message of the day
as well as other information. If the file ``.hushlogin'' exists in the
user's home directory or -q is specified, all of these messages are sup-
pressed. This is to simplify logins for non-human users, such as
uucp(1). Login then records an entry in utmpx(5) and the like, and exe-
cutes the user's command interpreter (or the program specified on the
command line if -f is specified).
Login enters information into the environment (see environ(7)) specifying
the user's home directory (HOME), command interpreter (SHELL), search
path (PATH), terminal type (TERM) and user name (both LOGNAME and USER).
The standard shells, csh(1) and sh(1), do not fork before executing the
login utility.
FILES
/etc/motd message-of-the-day
/etc/nologin disallows logins
/var/run/utmpx current logins
/var/mail/user system mailboxes
.hushlogin makes login quieter
SEE ALSO
chpass(1), passwd(1), rlogin(1), getpass(3), utmpx(5), environ(7)
HISTORY
A login appeared in Version 6 AT&T UNIX.
4th Berkeley Distribution May 5, 1994 4th Berkeley Distribution
Mac OS X 10.5.2 - Generated Sun Mar 23 09:24:41 CDT 2008