TTYS(5) BSD File Formats Manual TTYS(5)NAMEttys — terminal initialization information
DESCRIPTION
The file ttys contains information that is used by various routines to
initialize and control the use of terminal special files. This informa‐
tion is read with the getttyent(3) library routines.
There is one line in the ttys file per special device file. Fields are
separated by tabs and/or spaces. Fields comprising more than one word
should be enclosed in double quotes (``"''). Blank lines and comments
may appear anywhere in the file; comments are delimited by hash marks
(``#'') and new lines. Any unspecified fields will default to null.
Each line in ttys has the format:
tty command type flags
The first field is the name of the terminal special file as it is found
in /dev.
The second field of the file is the command to execute for the line, usu‐
ally getty(8), which initializes and opens the line, setting the speed,
waiting for a user name and executing the login(1) program. However, it
can be any desired command, for example the start up for a window system
terminal emulator or some other daemon process, and can contain multiple
words if quoted.
The third field is the type of terminal usually connected to that tty
line, normally the one found in the termcap(5) data base file. The envi‐
ronment variable TERM is initialized with the value by either getty(8) or
login(1).
The remaining fields set flags in the ty_status entry (see getttyent(3))
or specify a window system process that init(8) will maintain for the
terminal line or a key into a database of tty attributes (currently
unused).
on or off
init(8) should (or should not) execute the command given in the
second field.
secure If on is specified, allows users with a uid of 0 (e.g. "root")
to login on this line.
local Sets the TIOCFLAG_CLOCAL tty(4) flag for the device. This will
cause the termios(4) CLOCAL flag to be set on every open and
thus modem control signal lines will be ignored by default.
softcar Causes the driver to ignore hardware carrier on the line (by
setting the TIOCFLAG_SOFTCAR tty(4) flag).
rtscts Sets the TIOCFLAG_CRTSCTS tty(4) flag for the device to enable
RTS / CTS "hardware" flow control by default.
mdmbuf Sets the TIOCFLAG_MDMBUF tty(4) flag for the device to enable
DTR / DCD "hardware" flow control by default.
The flags "local", "rtscts", "mdmbuf", and "softcar" modify the default
behaviour of the terminal line, and their actions are device driver
dependent. These flag fields should not be quoted.
The string ``window='' may be followed by a quoted command string which
init(8) will execute before starting the command specified by the second
field.
The string ``class='' may be followed by a quoted string used as a key
into a database of attributes for that category of tty. See getttynam(3)
for more information on this feature.
After changing the ttys file a SIGHUP signal can be sent to init(8) with
the command “kill -s HUP 1”. On receipt of this signal, init(8) will re-
read the ttys file and spawn any necessary getty(8) processes.
Nota Bene: Sending SIGHUP to init(8) does not change the state of the
various tty(4) device flags listed above; the ttyflags(8) program must be
run for changes in those flags to take effect on the devices.
FILES
/etc/ttys
EXAMPLES
# root login on console at 1200 baud
console "/usr/libexec/getty std.1200" vt100 on secure
# dialup at 1200 baud, no root logins
ttyd0 "/usr/libexec/getty d1200" dialup on # 555-1234
# Mike's terminal: hp2621
ttyh0 "/usr/libexec/getty std.9600" hp2621-nl on # 457 Evans
# John's terminal: vt100
ttyh1 "/usr/libexec/getty std.9600" vt100 on # 459 Evans
# terminal emulate/window system
ttyv0 "/usr/new/xterm -L :0" vs100 on window="/usr/new/Xvs100 0"
# Network pseudo ttys-- don't enable getty
ttyp0 none network
ttyp1 none network off
SEE ALSOlogin(1), getttyent(3), ttyslot(3), tty(4), gettytab(5), termcap(5),
getty(8), init(8), ttyflags(8)HISTORY
A ttys file appeared in Version 6 AT&T UNIX.
BSD October 7, 2006 BSD
