LOGIN(M)                 XENIX System V                  LOGIN(M)



     Name
          login - Gives access to the system.

     Description
          The login command is used at the beginning of each terminal
          session and allows you to identify yourself to the system.
          It cannot be invoked except when a connection is first
          established, or after the previous user has logged out by
          sending an end-of-file ( Ctrl-D ) to his initial shell.

          login prompts for your user name, and if appropriate, your
          password.  Echoing is turned off (where possible) while
          entering your password, so it will not appear on the written
          record of the session.

          If password aging has been invoked by the superuser on your
          behalf, your password may have expired.  In this case, you
          will be shunted into passwd(C) to change it, after which you
          may attempt to log in again.

          If you do not complete the login successfully within a
          certain period of time (e.g., one minute), you are likely to
          be returned to the ``login:'' prompt or silently
          disconnected from a dial-up line.

          After a successful login, accounting files (/etc/utmp and
          /etc/wtmp) are updated, you are told if you have any mail,
          and the start-up profile files (i.e., /etc/profile and
          $HOME/.profile), if any, are executed.  See profile(M).

          login checks /etc/default/login for ULIMIT (maximum file
          size in 512 byte blocks, default is 2,097,152), and for
          environment variables, such as TZ (time zone), HZ (hertz),
          and ALTSHELL (allows other than sh shell types).  Other
          entries sometimes found in /etc/default/login are IDLEWEEKS,
          CONSOLE, and PASSREQ.  IDLEWEEKS=n, where n is a number of
          weeks, works in conjunction with pwadmin(C).  If a password
          has expired, you are prompted to choose a new one.  If it
          has expired beyond IDLEWEEKS, the user is not allowed to log
          in, and must consult system administrator.  The
          CONSOLE=/dev/???  entry means that root can only log in on
          the /dev listed. PASSREQ=YES, if set, forces you to select a
          password if you do not have one.

          login initializes the user and group IDs and the working
          directory, then executes a command interpreter (usually
          sh(C)) according to specifications found in the /etc/passwd
          file.  Argument 0 of the command interpreter is a dash (-)
          followed by the last component






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     LOGIN(M)                 XENIX System V                  LOGIN(M)



          of the interpreter's pathname.  The environment (see
          environ(M)) is initialized to:

               HOME= your-login-directory

               PATH=:/bin:/usr/bin

          Initially, umask is set to octal 022 by login.

     Files
          /etc/utmp                  Information on current logins

          /etc/wtmp                  History of logins since last
          multiuser

          /usr/spool/mail/your-name  Mailbox for user your-name

          /etc/motd                  Message of the day

          /etc/default/login         Default values for environment
                                     variables

          /etc/passwd                Password file

          /etc/profile               System profile

          $HOME/.profile             Personal profile

     See Also
          environ(M), getty(M), machine(M), mail(C), newgrp(C),
          passwd(C), passwd(M), profile(M), su(C), sh(C), ulimit(S),
          umask(C), who(C).

     Diagnostics
          Login incorrect
               The user name or the password is incorrect.

          No shell, cannot open password file, no directory:
               Your account has not been properly set up.

          Your password has expired. Choose a new one.
               Password aging is implemented and yours has expired.

     Notes
          Under System V, only the superuser may execute login from a
          shell.  Hence, non-superusers must log out in order to log
          in as another user.  Pre-system III login, if invoked from
          the command line while someone is logged on already, logs
          the current user out and logs in the new user.  The current
          login nests, i.e., the current user is not logged out.
          Thus, it is somewhat like su(C), except that the new user's
          .login or .profile is run.  Permissions and environment are



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     LOGIN(M)                 XENIX System V                  LOGIN(M)



          those of the new user.  When the new user logs out, the
          previous user is still running.  This practice is not
          recommended, as nested logins can impair system performance.

          As explained in machine(M), when setting ULIMIT in the
          /etc/default/login file on filesystems with 1024 byte blocks
          (see machine(M)), be sure to specify even numbers, as the
          ULIMIT variable accepts a number of 512-byte blocks. The
          default is 2,097,152 blocks, or 1 gigabyte.  Use this
          variable to increase or decrease the maximum allowable file
          size.












































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