ttys(5)ttys(5)Namettys - terminal initialization data
Description
The file contains information used by various routines to initialize
and control the use of terminal special files. This file is created
when the system is installed and can be updated at any time.
Each terminal special file ( ) has a line in the file. Each line con‐
tains several fields. Fields are separated by tabs or spaces. A field
with more than one word should be enclosed in quotes. Blank lines and
comments can appear anywhere in the file. Comments begin with a number
sign (#) and are terminated by a newline character. Unspecified fields
default to the empty string or zero, as appropriate.
The format of each line is as follows:
name command type flag1 flag2 ...
name Is the name of the special file for the terminal in the
directory. Some examples are:
console
ttyd0
ttyd1
command Is the command to be executed each time the terminal is ini‐
tialized. This can happen when the system is booted, or when
the superuser adds new terminals to the file and initializes
the new terminals. The command is usually which performs
such tasks as baud-rate recognition, reading the login name,
and calling It can be any command you wish, such as the
startup command for a window system terminal emulator or a
command to maintain other daemon processes.
type Is the type of terminal normally connected to the terminal
special file. You can find the possible types by examining
the file on your system. The types available are given as
the third field in entries in that file. Some examples are:
vt100
vt200
dialup
flags Are the flags to be set in the or fields of the structure
returned by the routine. If the line ends in a comment, the
comment is included in the field of this structure.
These fields are used by the command that is executed when
terminals are initialized.
The flags are:
on Sets the TTY_ON bit in the field. This enables
logins for this terminal.
The default if this flag is not set is that logins
are disabled for the terminal.
off Clears the TTY_ON bit in the field. This disables
logins for this terminal.
secure Sets the TTY_SECURE bit in the field. This allows
the root user to log in on this terminal. (The on
flag should also be set.)
The default if this flag is not set is that the
root user cannot log in on this terminal.
su Sets the TTY_SU bit in the field, to allow a user
to su to root.
The default if this flag is not set is that users
cannot su to root on this terminal.
nomodem Sets the TTY_LOCAL bit in the field. The line
ignores modem signals. This is the default if nei‐
ther the modem nor nomodem flag is set.
modem Clears the TTY_LOCAL bit in the field. The line
recognizes modem signals.
The default if this flag is not set is nomodem.
That is, the line does not recognize modem signals.
shared Sets the TTY_SHARED bit in the field. The line can
be used for both incoming and outgoing connections.
The default if this flag is not set is that the
line cannot be used for incoming and outgoing con‐
nections.
termio Sets the TTY_TERMIO bit in the field. This flag
causes the terminal line to open with System Five
default termio attributes. If the termio flag is
not set, Berkeley compliant default terminal
attributes are used.
The flag is:
window="string"
The quoted string is a window system process that
maintains for the terminal line.
Examples
The following example permits the root user to log in on the console at
1200 baud:
console "/etc/getty std.1200" vt100 on secure
This example allows dialup at 1200 baud without root login:
ttyd0 "/etc/getty d1200" dialup on
These two examples allow login at 9600 baud with two different terminal
types: hp2621-nl and vt100. In this example, the terminals should be
set up to operate in 7-bit mode, because the std.9600 entry is speci‐
fied:
tty00 "/etc/getty std.9600" hp2621-nl on
tty01 "/etc/getty std.9600" vt100 on
This example shows the same two terminals as the previous example oper‐
ating in full 8-bit mode. Note the use of a different entry:
tty00 "/etc/getty 8bit.9600" hp2621-nl on
tty01 "/etc/getty 8bit.9600" vt100 on
These two examples show network pseudoterminals, which should not have
enabled:
ttyp0 none network
ttyp1 none network off
This example shows a terminal emulator and window-system startup entry
and should be typed all on one line:
:0 "/usr/bin/login -P /usr/bin/Xprompter -C /usr/bin/dxsession -e" none
on secure window="/usr/bin/Xcfb"
This example shows an example of an entry for an lta device:
tty01 "/etc/getty 8bit.9600" vt100 on modem secure # LAT
Any terminal configured to run in 8-bit mode should specify a entry
that declares 8-bit operation. The command field of the entry is used
to specify the entry. If the terminal device is set up to operate in
8-bit mode and the command field does not specify an 8-bit entry, out‐
put to the terminal appears as multinational characters. These charac‐
ters are the result of the program using the eighth bit of each charac‐
ter to represent parity attributes. By using an 8-bit entry, the high
order bit of each character is unaffected by the program. The examples
presented demonstrate the use of both 7- and 8-bit terminals.
Files
The full pathname for the file
See Alsologin(1), getttyent(3), gettytab(5), getty(8), init(8)
Guide to System Environment Setup
ttys(5)