login [-fp] [-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.  Alternately, the user can enter the password
     "s/key", in which case S/Key authentication of users is performed, as de-
     scibed in skey(1).  S/Key is a Trademark of Bellcore.

     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.

     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.

     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 unsucessful 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(1).  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))  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.

SEE ALSO

     chpass(1),  passwd(1),  rlogin(1),  skey(1),  getpass(3),  utmp(5),  env-
     iron(7,) fbtab(5)

HISTORY

     A login appeared in Version 6 AT&T UNIX.

4th Berkeley Distribution         May 5, 1994                                2