[EMAIL PROTECTED] (Niels M�ller) writes:
> Can you tell me (or give me a reference that explains)
>
> (i) how to use this feature, and
See -f in man page below.
> (ii) how to detect that it is available.
It is available in all the BSDs. It would be great if Linux adopted
the convention, but I'm not in a position to force that. As for how to
detect it, well, you can assume it on NetBSD, FreeBSD, BSDI and company...
Perry
LOGIN(1) NetBSD Reference Manual LOGIN(1)
NAME
login - log into the computer
SYNOPSIS
login [-fps] [-h hostname] [user]
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. 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 normal password or the S/Key re�
sponse. Neither will be echoed.
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.
-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 op�
tion disables this behavior.
-s Require a secure authentication mechanism like Kerberos or S/Key
to be used.
If the file /etc/nologin exists, login displays 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, all of these messages are suppressed. This is to
simplify logins for non-human users, such as uucp(1). login then records
an entry in the wtmp(5) and utmp(5) files, executes site-specific login
commands via the ttyaction(3) facilty with an action of "login", and exe�
cutes the user's command interpreter.
login enters information into the environment (see environ(7)) specify�
ing 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/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
utmp(5), environ(7)
HISTORY
A login appeared in Version 6 AT&T UNIX.
TRADEMARKS AND PATENTS
S/Key is a Trademark of Bellcore.
4th Berkeley Distribution May 5, 1994 2
