NAME
login
—
log into the computer
SYNOPSIS
login |
[-fp ] [-h
hostname] [user] |
DESCRIPTION
Thelogin
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 configurable via
pam(8). Password authentication is the default.
The following options are available:
-f
- When a user name is specified, this option indicates 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.
-h
- Specify 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.
Login access can be controlled via login.access(5) or the login class in login.conf(5), 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.
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 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). 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 controls
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 identical to this utility. Consult the
builtin(1) manual page.
The login
utility will submit an audit
record when login succeeds or fails. Failure to determine the current
auditing state will result in an error exit from
login
.
FILES
- /etc/fbtab
- changes device protections
- /etc/login.conf
- login class capabilities database
- /var/run/motd
- message-of-the-day
- /var/mail/user
- system mailboxes
- .hushlogin
- makes login quieter
- /etc/pam.d/login
- pam(8) configuration file
- /etc/security/audit_user
- user flags for auditing
- /etc/security/audit_control
- global flags for auditing
SEE ALSO
builtin(1), chpass(1), csh(1), newgrp(1), passwd(1), rlogin(1), getpass(3), fbtab(5), login.access(5), login.conf(5), environ(7)
HISTORY
A login
utility appeared in
Version 6 AT&T UNIX.