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:
Note that standard getty usually only supports \b, \r and \n.
The various fields are:
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) .
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) .
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:
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>
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/getty- defs, 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:
B19200 SANE VERASE \b VINTR \003 HUPCL # \n\D \T \N Users @!login: #19200mg
mgetty(8) , getty(8) , login(1) , ioctl(2) , termio(7) , termios(7) .
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