LOGIN(N)                                                 LOGIN(N)



NAME
       login - Begin session on the system

SYNOPSIS
       login [-p] [username] [ENV=VAR ...]
       login [-p] [-h host] [-f username]
       login [-p] -r host

DESCRIPTION
       login  is used to establish a new session with the system.
       It is normally invoked automatically by responding to  the
       login:  prompt  on the user's terminal.  login may be spe-
       cial to the shell and may not be invoked as a sub-process.
       Typically,  login  is  treated  by the shell as exec login
       which causes the user to  exit  from  the  current  shell.
       Attempting  to  execute login from any shell but the login
       shell will produce an error message.

       When invoked from the login: prompt, the  user  may  enter
       environmental  variables  after the username.  These vari-
       ables are entered in the form NAME=VALUE.  Not  all  vari-
       ables  may  be  set in the fashion, notably PATH, HOME and
       SHELL.  Additionally, IFS may be inhibited if  the  user's
       login shell is /bin/sh.

       The  user is then prompted for a password, where appropri-
       ate.  Echoing is disabled to prevent revealing  the  pass-
       word.   Only  a small number of password failures are per-
       mitted before login exits and the communications  link  is
       severed.

       If  password  aging has been enabled for your account, you
       may be prompted for a new password before proceeding.  You
       will  be  forced  to provide your old password and the new
       password before continuing.  Please refer  to  passwd  (1)
       for more information.

       After a successful login, you will be informed of any sys-
       tem messages and the presence of mail.  You may  turn  off
       the  printing  of  the  system message file, /etc/motd, by
       creating a  zero-length  file  .hushlogin  in  your  login
       directory.   The mail message will be one of "You have new
       mail.", "You have mail.", or "No Mail." according  to  the
       condition of your mailbox.

       Your user and group ID will be set according to their val-
       ues in the /etc/passwd file.  The value for $HOME, $SHELL,
       $PATH, $LOGNAME, and $MAIL are set according to the appro-
       priate fields in the password entry.   Ulimit,  umask  and
       nice  values  may  also be set according to entries in the
       GECOS field.

       On some installations, the  environmental  variable  $TERM
       will  be initialize to the terminal type on your tty line,
       as specified in /etc/ttytype.

       An initialization script for your command interpreter  may
       also  be executed.  Please see the appropriate manual sec-
       tion for more information on this function.

       A subsystem login is indicated by the presense of a "*" as
       the  first  character  of  the login shell. The given home
       directory will be used as the root  of  a  new  filesystem
       which the user is actually logged into.

OPTIONS
       -p     Preserve environment.

       -f     Do not perform authentication, user is preauthenti-
              cated.

       -h     Name of the remote host for this login.

       -r     Perform autologin protocol for rlogin.

       The -r -h and -f options  are  only  used  when  login  is
       invoked by root.

CAVEATS
       This  version  of login has many compilation options, only
       some of which may be in use at any particular site.

       The location of files is subject to differences in  system
       configuration.

FILES
       /var/run/utmp - list of current login sessions
       /var/log/wtmp - list of previous login sessions
       /etc/passwd - user account information
       /etc/shadow - encrypted passwords and age information
       /etc/motd - system message file
       /etc/nologin - prevent non-root users from logging in
       /etc/ttytype - list of terminal types
       $HOME/.profile - initialization script for default shell
       $HOME/.hushlogin - suppress printing of system messages

SEE ALSO
       getty(y), mail(l), passwd(d), sh(h), su(u), login.defs(s),
       passwd(d), nologin(n)

AUTHOR
       Julianne Frances Haugh (jfh@austin.ibm.com)



                                                         LOGIN(N)