FreeBSD man pages : login (1)
LOGIN(1) FreeBSD General Commands Manual LOGIN(1)
login - log into the computer
login [-fp] [-h hostname] [user]
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
-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.
-p By default, login discards any previous environment. The -p
option disables this behavior.
If the file /var/run/nologin exists, login displays its contents to the
user and exits. This is used by shutdown(8) to prevent users from log-
ging in when the system is about to go down.
If the file /etc/login.access exists, login checks to see if the user and
host pair are specifically allowed or denied access. Login access may
also be controlled via the login class, which provides allow and deny
records based on time, tty and remote host name.
If the file /etc/fbtab exists, login changes the protection and ownership
of certain devices specified in this file.
If the file /etc/skeykeys exists, login will offer S/key password valida-
tion if the user has an entry in the file. /etc/skey.access controls
from which hosts and/or networks the use of S/key passwords are obli-
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, all of these messages are suppressed. This is to
simplify logins for non-human users, such as uucp(1). The login utility
then records an entry in the wtmp(5) and utmp(5) files and executes the
user's command interpreter.
The login utility enters information into the environment (see
environ(7)) specifying the user's home directory (HOME), command inter-
preter (SHELL), search path (PATH), terminal type (TERM) and user name
(both LOGNAME and USER). Other environment variables may be set due to
entries in the login class capabilities database, for the login class
assigned in the user's system passwd record. The login class also con-
trols the maximum and current process resource limits granted to a login,
process priorities and many other aspects of a user's login environment.
Some shells may provide a builtin login command which is similar or iden-
tical to this utility. Consult the builtin(1) manual page.
/etc/fbtab changes device protections
/etc/login.access login access control table
/etc/login.conf login class capabilities database
/var/run/nologin disallows logins
/etc/skey.access skey password control table
/etc/skeykeys skey password database
/var/run/utmp current logins
/var/log/lastlog last login account records
/var/log/wtmp login account records
/var/mail/user system mailboxes
.hushlogin makes login quieter
/etc/auth.conf configure authentication services
/etc/pam.conf if login is configured with PAM support, it uses
/etc/pam.conf entries with service name ``login''
builtin(1), chpass(1), csh(1), passwd(1), rlogin(1), skey(1), getpass(3),
fbtab(5), login.access(5), login.conf(5), nologin(5), skey.access(5),
utmp(5), environ(7), nologin(8), pam(8)
A login utility appeared in Version 6 AT&T UNIX.
FreeBSD 4.8 May 5, 1994 FreeBSD 4.8