4.3BSD-UWisc/man/cat8/getty.8
GETTY(8) UNIX Programmer's Manual 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 termi-
nal 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 termi-
nal 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 banner of the login prompt will include
the system hostname. Then the user's name is read, a char-
acter 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 character. 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 alphabetic 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 argu-
ment.
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
Printed 12/27/86 May 22, 1986 1
GETTY(8) UNIX Programmer's Manual GETTY(8)
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 configuration, 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)
Printed 12/27/86 May 22, 1986 2