LOGIN(1) Commands and Applications LOGIN(1)
login - log into the computer
login [-fp] [-h hostname] [user]
The login utility logs users (and pseudo-users) into the computer sys-
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 /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.
If the file /etc/fbtab exists, login changes the protection and owner-
ship of certain devices specified in this file.
Immediately after logging a user in, login displays the system copy-
right 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 and executes the
user's command interpretor.
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
The standard shells, csh(1) and sh(1), do not fork before executing the
/etc/fbtab changes device protections
/etc/nologin disallows logins
/var/run/utmp current logins
/var/log/wtmp login account records
/var/mail/user system mailboxes
.hushlogin makes login quieter
chpass(1), passwd(1), rlogin(1), getpass(3), fbtab(5), utmp(5), envi-
A login appeared in Version 6 AT&T UNIX.
GNO 15 April 1998 LOGIN(1)
Man(1) output converted with