LOGIN(1) | General Commands Manual | LOGIN(1) |
login
—
login |
[-Ffps ] [-a
address] [-h
hostname] [user] |
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. If the user can
be authenticated via S/Key, then the S/Key challenge is incorporated in the
password prompt. The user then has the option of entering their Kerberos or
normal password or the S/Key response. Neither will be echoed.
The options are as follows:
-a
-a
option specifies the address of 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.-F
-F
option acts like the
-f
option, but also indicates to
login
that it should attempt to rewrite an
existing Kerberos 5 credentials cache (specified by the KRB5CCNAME
environment variable) after dropping permissions to the user logging in.
This flag is not supported under
pam(8).-f
-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.-h
-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
login
discards any previous
environment. The -p
option disables this
behavior.-s
If a user other than the superuser attempts to login while the
file /etc/nologin exists,
login
displays its contents to the user and exits.
This is used by shutdown(8)
to prevent normal 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, all of these messages are suppressed. This is to simplify logins
for non-human users. login
then records an entry in
the wtmp(5) and
utmp(5) files, executes
site-specific login commands via the
ttyaction(3) facility with
an action of "login", and executes the user's command
interpreter.
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 user's login experience can be customized using login class capabilities as configured in /etc/login.conf and documented in login.conf(5).
The standard shells,
csh(1) and
sh(1), do not fork before
executing the login
utility.
login
appeared in Version 6
AT&T UNIX.
November 19, 2008 | NetBSD 9.4 |