NAME    [Toc]    [Back]

     login - log into the computer

SYNOPSIS    [Toc]    [Back]

     login  [-fp]  [-h  hostname]   [-L   local-ip-address]   [-R
remote-ip-address]
           [-u username] [user]

DESCRIPTION    [Toc]    [Back]

     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 normally done via passwords, though external  authentication mechanisms
     may  be  used (see login.conf(5)).  To specify the alternate
authentication
     mechanism style, the string :style is appended to  the  user
name (i.e.,
     user:style).

     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
             superuser or when an already logged in user is  logging in as
             themselves.

     -h hostname
             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 superuser.

     -L       The  -L  option specifies the local IP address of a
socket such as
             telnetd would use.  This information is passed on to
any classify
             script (see login.conf(5)).

     -p      By default, login discards any previous environment.
The -p option
 disables this behavior.

     -R      The -R option specifies the remote IP address  of  a
socket such as
             telnetd would use.  This information is passed on to
any classify
             script (see login.conf(5)).

     -u username
             Specifies the remote user that initiated the connection.  It is
             used  by  various  daemons such as telnetd(8).  This
option may only
             be used by the superuser.

     If the file /etc/nologin exists (and  the  ``ignorenologin''
boolean is not
     set  in the user's login class), 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.

     If  the file /etc/fbtab exists, login changes the protection
and ownership
     of certain devices specified in this file.

     If the file /var/log/failedlogin exists, login  will  record
failed login
     attempts 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  date
and time of
     the     last     unsuccessful    login    (if    the    file
/var/log/failedlogin exists),
     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.   login  then  records  an  entry  in  the wtmp(5) and
utmp(5) files 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  standard  shells,  csh(1) and sh(1), do not fork before
executing the
     login utility.

     Note that if login is invoked by a non-root  user,  it  will
execute su(1)
     in login emulation mode instead.

ENVIRONMENT    [Toc]    [Back]

     login sets the following environment variables:

     HOME         The  user's home directory, as specified by the
password
                 database.

     SHELL       The user's shell, as specified by  the  password
database.

     TERM         The  user's  terminal type, if it can be determined.

     LOGNAME     The user's login name.

     USER        Same as LOGNAME.

     REMOTEHOST  The name of the host from which the user  logged
in, if the -h
                 flag was specified.

     REMOTEUSER   The  name  of the remote user who initiated the
connection, if
                 the -u flag was specified.

     Other   environment   variables   may   be   specified    in
/etc/login.conf via the
     ``setenv'' capability.

FILES    [Toc]    [Back]

     /etc/fbtab            changes device protections
     /etc/login.conf       login configuration
     /etc/motd             message-of-the-day
     /etc/nologin          disallows logins
     /var/run/utmp         current logins
     /var/log/failedlogin  failed login account records
     /var/log/lastlog      last login account records
     /var/log/wtmp         login account records
     /var/mail/user        system mailboxes
     .hushlogin            makes login quieter

SEE ALSO    [Toc]    [Back]

     chpass(1), passwd(1), su(1), telnet(1), getpass(3), setusercontext(3),
     fbtab(5), login.conf(5), utmp(5), environ(7)

HISTORY    [Toc]    [Back]

     A login utility appeared in Version 3 AT&T UNIX.

OpenBSD      3.6                            May      5,      1994