LOGIN(1)                                                 LOGIN(1)



     NAME
          login - sign on

     SYNOPSIS
          login [ name [ env-var ... ]]

     DESCRIPTION
          The login command is used at the beginning of each terminal
          session and allows you to identify yourself to the system.
          It may be invoked as a command or by the system when a
          connection is first established.  Also, it is invoked by the
          system when a previous user has terminated the initial shell
          by typing a cntrl-d to indicate an ``end-of-file.''  (See
          How to Get Started at the beginning of this volume for
          instructions on how to dial up initially.)

          If login is invoked as a command it must replace the initial
          command interpreter.  This is accomplished by typing:
               exec login
          from the initial shell.

          login asks for your user name (if not supplied as an
          argument), and, if appropriate, your password.  Echoing is
          turned off (where possible) during the typing of your
          password, so it will not appear on the written record of the
          session.

          At some installations, an option may be invoked that will
          require you to enter a second ``dialup'' password.  This
          will occur only for dial-up connections, and will be
          prompted by the message ``dialup password:''.  Both
          passwords are required for a successful login.

          If you do not complete the login successfully within a
          certain period of time (e.g., one minute), you are likely to
          be silently disconnected.

          After a successful login, accounting files are updated, the
          procedure /etc/profile is performed, the message-of-the-day,
          if any, is printed, the user-ID, the group-ID, the working
          directory, and the command interpreter (usually sh(1)) is
          initialized, and the file .profile in the working directory
          is executed, if it exists.  These specifications are found
          in the /etc/passwd file entry for the user.  The name of the
          command interpreter is - followed by the last component of
          the interpreter's path name (i.e., -sh).  If this field in
          the password file is empty, then the default command
          interpreter, /bin/sh is used.  If this field is ``*'', then
          the named directory becomes the root directory, the starting
          point for path searches for path names beginning with a /.
          At that point login is re-executed at the new level which
          must have its own root structure, including /etc/login and



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     LOGIN(1)                                                 LOGIN(1)



          /etc/passwd.

          The basic environment is initialized to:

               HOME=your-login-directory
               PATH=:/bin:/usr/bin
               SHELL=last-field-of-passwd-entry
               MAIL=/usr/mail/your-login-name
               TZ=timezone-specification

          The environment may be expanded or modified by supplying
          additional arguments to login, either at execution time or
          when login requests your login name.  The arguments may take
          either the form xxx or xxx=yyy. Arguments without an equal
          sign are placed in the environment as
               Ln=xxx
          where n is a number starting at 0 and is incremented each
          time a new variable name is required.  Variables containing
          an = are placed into the environment without modification.
          If they already appear in the environment, then they replace
          the older value.  There are two exceptions.  The variables
          PATH and SHELL cannot be changed.  This prevents people,
          logging into restricted shell environments, from spawning
          secondary shells which are not restricted.  Both login and
          getty understand simple single-character quoting
          conventions.  Typing a backslash in front of a character
          quotes it and allows the inclusion of such things as spaces
          and tabs.

     FILES
          /etc/utmp            accounting
          /etc/wtmp            accounting
          /usr/mail/your-name  mailbox for user your-name
          /etc/motd            message-of-the-day
          /etc/passwd          password file
          /etc/profile         system profile
          .profile             user's login profile

     SEE ALSO
          mail(1), newgrp(1), sh(1), su(1M).
          passwd(4), profile(4), environ(5) in the Programmer's
          Reference Manual.

     DIAGNOSTICS
          login incorrect if the user name or the password cannot be
          matched.
          No shell, cannot open password file, or no directory:
          consult a UNIX system programming counselor.
          No utmp entry. You must exec "login" from the lowest level
          "sh" if you attempted to execute login as a command without
          using the shell's exec internal command or from other than
          the initial shell.



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     LOGIN(1)                                                 LOGIN(1)



     ORIGIN
          AT&T V.3





















































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