mgettydefs - speed and terminal settings used by mgetty
The /etc/gettydefs file contains information used by
mgetty(1) to set up the speed and terminal settings for a line. It
also supplies information on what the login prompt should look
like.
Many versions of UNIX have a version of getty(1) that also
reads /etc/gettydefs. Both mgetty and getty expect
similar formats in /etc/gettydefs except that, when used by
mgetty, extended functionality is available. Even so, the additional
functions are simply ignored by standard getty, so they can co-exist
using the same file. Note, however, that mgetty can be compiled to
use a file different from /etc/gettydefs if your getty gets
upset about the extensions. This manual page documents /etc/gettydefs
and describes the extended functionality available when used by
mgetty(1). This document will refer to getty(1) except where
mgetty's behaviour is different.
Each entry in /etc/gettydefs has the following format:
- label# initial-flags # final-flags # login-prompt #next-label
Each entry is followed by a blank line. The login prompt field can
contain quoted characters which will be converted to other values. The
sequences and their substitutions are:
- \n
- newline
- \r
- carriage return
- \g
- beep
- \b
- backspace
- \v
- vertical tab (VT)
- \f
- formfeed
- \t
- tab
- \L
- portname
- \C
- time in ctime(3) format.
- \N
- number of users currently logged in
- \U
- number of users currently logged in
- \D
- date in DD/MM format
- \T
- time in hh:mm:ss format
- \I
- modem CONNECT attributes
- \sequence
- where "sequence" is a valid strtol format, such as: \0nnn
(octal), \0xnnn (hex), or \nnn (decimal).
Note that standard getty usually only supports \b, \r and
\n.
The various fields are:
- label
- This is the string against which getty tries to match its second
argument. It is often the speed, such as 1200, at which the
terminal is supposed to run, but it need not be (see below).
- initial-flags
- These flags are the initial ioctl(2) settings to which the terminal
is to be set if a terminal type is not specified to getty. The
flags that getty understands are the ones listed in
termio(7)). mgetty is usually compiled for termios(7)
and often has a more complete set than getty.
- Normally only the
speed flag is required in the
- initial-flags. getty automatically sets the terminal to raw
input mode and takes care of the other flags. If the "-s" option
is used with mgetty(1) the speed setting is ignored. The
initial-flag settings remain in effect until getty executes
login(1).
- final-flags
- These flags take the same values as the initial-flags and are set
just before getty executes login. The speed flag is again
required, except with mgetty if the -s flag was supplied. Two other
commonly specified final-flags are TAB3, so that tabs are
sent to the terminal as spaces, and HUPCL, so that the line is hung
up on the final close.
- login-prompt
- This entire field is printed as the login-prompt. Unlike the above
fields where white space (a space, tab or new-line) is ignored, they are
included in the login-prompt field. This field is ignored if the
"-p" option has been specified to mgetty(1).
- next-label
- specifies the label to use if the user user types a <break>
character, or getty detects a reception error. Getty
searches for the entry with next-label as its label field
and set up the terminal for those settings. Usually, a series of speeds
are linked together in this fashion, into a closed set; for instance,
2400 linked to 1200, which in turn is linked to 300,
which finally is linked to 2400. next-label is ignored with
mgetty(1).
Several additional composite settings are available for
initial-flags and final-flags. The following composite flags
are supported by mgetty and are usually supported by
getty:
- SANE
- equivalent to ``stty sane''. (BRKINT, IGNPAR, ISTRIP, ICRNL, IXON, OPOST,
CS8, CREAD, ISIG, ICANON, ECHO, ECHOK)
- ODDP
- Odd parity (CS7, PARENB, PARODD)
- PARITY,EVENP
- even parity (CS7, PARENB)
- -ODDP,-PARITY,-EVENP
- no parity (resets PARENB, PARODD, and sets CS8)
- RAW
- raw I/O (no canonical processing) (turns off OPOST, ICANON)
- -RAW,COOKED
- enable canonical processing (turns on OPOST, ICANON)
- NL
- Ignore newlines. (ICRNL, ONLCR)
- -NL
- Respect newlines (turns INLCR, IGNCR, ICRNL, ONLCR, OCRNL, ONLRET
off)
- LCASE
- Ignore case - treat all as lowercase. (IUCLC, OLCUC, XCASE) Is set if
mgetty believes login is entirely uppercase.
- -LCASE
- Repect case (turns off IUCLC, OLCUC and XCASE)
- TABS
- output tabs as tabs
- -TABS,TAB3
- output tabs as spaces
- EK
- Sets VERASE to "#" and VKILL to CKILL respectively. (note that
while many gettys default VERASE to "#". mgetty defaults
VERASE to backspace.)
Additionally, mgetty (but not getty) can set any of
the control characters listed in the c_cc termio(termios) structure
by the use of two tokens:
<character name> <value>
Eg:
VERASE ^h
The value can be set as ``^<character>'', ``\nnn'' or
``\<character>'' (normal UNIX \ escapes).
See the termio(7) or termios(7) manual pages to a
list of which ``V'' variables can be changed. Note that many of these can be
changed in the c_cc array, but won't have any effect.
If getty is called without a second argument, the first
entry of /etc/gettydefs is used by getty, thus making the
first entry of /etc/gettydefs the default entry. It is also used if
getty cannot find the specified label. Mgetty use a
default label of ``n'', but this can be changed in the configuration. If
/etc/gettydefs itself is missing, there is one entry built into the
command which brings up a terminal at 300 (configuration parameter in
mgetty) baud.
It is strongly recommended that after making or modifying
/etc/gettydefs, it be run through getty with the check option
to be sure there are no errors.
The following two lines show an example of 300/1200 baud toggle,
which is useful for dial-up ports:
- 1200# B1200 HUPCL # B1200 SANE IXANY TAB3 #login: #300
300# B300 HUPCL # B300 SANE IXANY TAB3 #login: #1200
The following line shows a typical 9600 baud entry for a
hard-wired connection (not currently supported for mgetty):
- 9600# B9600 # B9600 SANE IXANY IXANY ECHOE TAB3 #login: #9600
The following line is a typical smart-modem setup, suitable for
mgetty:
-
19200mg#
B19200 #
B19200 SANE VERASE \b VINTR \003 HUPCL #
\n\D \T \N Users @!login: #19200mg