GETTY(8)                                                              GETTY(8)



NAME
       getty  - set terminal mode

SYNOPSIS
       /etc/getty [ type [ tty ] ]

DESCRIPTION
       _G_e_t_t_y  is  usually  invoked  by  _i_n_i_t(8) to open and initialize the tty
       line, read a login name, and invoke _l_o_g_i_n(1).  _g_e_t_t_y attempts to  adapt
       the system to the speed and type of terminal being used.

       The  argument  _t_t_y  is  the special device file in /dev to open for the
       terminal (e.g., ‘‘ttyh0’’).  If there is no argument or the argument is
       ‘‘-’’, the tty line is assumed to be open as file descriptor 0.

       The  _t_y_p_e  argument  can  be used to make _g_e_t_t_y treat the terminal line
       specially.  This argument is used as  an  index  into  the  _g_e_t_t_y_t_a_b(5)
       database, to determine the characteristics of the line.  If there is no
       argument, or there is no such table, the default  table  is  used.   If
       there  is  no /etc/gettytab a set of system defaults is used.  If indi‐
       cated by the table located, _g_e_t_t_y will clear the terminal screen, print
       a banner heading, and prompt for a login name.  Usually either the ban‐
       ner of the login prompt will include the  system  hostname.   Then  the
       user’s  name  is  read,  a character at a time.  If a null character is
       received, it is assumed to be  the  result  of  the  user  pushing  the
       ‘break’  (‘interrupt’)  key.  The speed is usually then changed and the
       ‘login:’ is typed again; a second ‘break’ changes the speed  again  and
       the  ‘login:’  is typed once more.  Successive ‘break’ characters cycle
       through the same standard set of speeds.

       The user’s name is terminated by a new-line or carriage-return  charac‐
       ter.   The  latter  results  in  the system being set to treat carriage
       returns appropriately (see _t_t_y(4)).

       The user’s name is scanned to see if it contains any lower-case  alpha‐
       betic  characters;  if  not, and if the name is nonempty, the system is
       told to map any future upper-case  characters  into  the  corresponding
       lower-case characters.

       Finally, _l_o_g_i_n is called with the user’s name as an argument.

       Most  of the default actions of _g_e_t_t_y can be circumvented, or modified,
       by a suitable _g_e_t_t_y_t_a_b table.

       _G_e_t_t_y can be set to timeout after some interval, which will cause  dial
       up  lines  to  hang  up  if  the  login  name is not entered reasonably
       quickly.

DIAGNOSTICS
       _t_t_y_x_x: No such device or address.  _t_t_y_x_x: No such file or  address.   A
       terminal  which  is turned on in the _t_t_y_s file cannot be opened, likely
       because the requisite lines are either not configured into the  system,
       the associated device was not attached during boot-time system configu‐
       ration, or the special file in /dev does not exist.

FILES
       /etc/gettytab

SEE ALSO
       gettytab(5), init(8), login(1), ioctl(2), tty(4), ttys(5)



4th Berkeley Distribution        May 22, 1986                         GETTY(8)