GETTY(1M-SysV) RISC/os Reference Manual GETTY(1M-SysV)
NAME
getty, uugetty - set terminal type, modes, speed, and line
discipline
SYNOPSIS
/etc/getty [-h] [-ttimeout] line [ speed [ type [ linedisc ]
] ]
/usr/lib/uucp/uugetty [-h] [-ttimeout] [-r] line [ speed [
type [ linedisc ] ] ]
/etc/getty -c file
/usr/lib/uucp/uugetty -c file
DESCRIPTION
getty and uugetty are programs which are invoked by
init(1M). Except as noted below, getty and uugetty are
identical. Each may be the second process in the series
(init-getty-login-shell) that ultimately connects a user
with the system. In the following discussion, ``getty'' may
be taken to include ``uugetty,'' except as noted. getty can
only be executed by the super-user; that is, a process with
the user-ID of root. Initially getty prints the login mes-
sage field for the entry it is using from /etc/gettydefs.
getty reads the user's login name and invokes the login(1)
command with the user's name as argument. While reading the
name, getty attempts to adapt the system to the speed and
type of terminal being used. It does this by using the
options and arguments specified. line is the name of a tty
line in /dev to which getty is to attach itself. getty uses
this string as the name of a file in the /dev directory to
open for reading and writing. Unless getty is invoked with
the -h flag, getty will force a hangup on the line by set-
ting the speed to zero before setting the speed to the
default or specified speed. The -t flag plus timeout (in
seconds), specifies that getty should exit if the open on
the line succeeds and no one types anything in the specified
number of seconds.
speed, the optional second argument, is a label to a speed
and tty definition in the file /etc/gettydefs. This defini-
tion tells getty at what speed to initially run, what the
login message should look like, what the initial tty set-
tings are, and what speed to try next should the user indi-
cate that the speed is inappropriate (by typing a <break>
character). The default speed is 300 baud.
type, the optional third argument, is a character string
describing to getty what type of terminal is connected to
the line in question. getty recognizes the following types:
none default
ds40-1 Dataspeed40/1
tektronix,tek Tektronix
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vt61 DEC vt61
vt100 DEC vt100
hp45 Hewlett-Packard 45
c100 Concept 100
The default terminal is none; i.e., any crt or normal termi-
nal unknown to the system. Also, for terminal type to have
any meaning, the virtual terminal handlers must be compiled
into the operating system. They are supplied in the operat-
ing system by default.
linedisc, the optional fourth argument, is a character
string describing which line discipline to use in communi-
cating with the terminal. The following line disciplines
are available:
LDISC0 This is the default line discipline, and is compa-
tible with the default System V Release 3.0 line
discipline and with the 4.3 BSD "old" line discip-
line.
LDISC1 This is an extended line discipline, with many of
the features of the 4.3 BSD "new" line discipline,
but lacking a number of those features. (See
stty(1-SysV) for details.)
LDISC2 This is an extended line discipline, compatible
with the 4.3 BSD "new" line discipline. (Again,
see stty(1-SysV) for details.)
When given no optional arguments, getty sets the speed of
the interface to 300 baud, specifies that raw mode is to be
used (awaken on every character), that echo is to be
suppressed, either parity allowed, new-line characters will
be converted to carriage return-line feed, and tab expansion
performed on the standard output. It types the login mes-
sage before reading the user's name a character at a time.
If a null character (or framing error) is received, it is
assumed to be the result of the user pushing the ``break''
key. This will cause getty to attempt the next speed in the
series. The series that getty tries is determined by what
it finds in /etc/gettydefs.
After the user's name has been typed in, it is terminated by
a new-line or carriage-return character. The latter results
in the system being set to treat carriage returns appropri-
ately (see ioctl(2)).
The user's name is scanned to see if it contains any lower-
case alphabetic characters; if not, and if the name is non-
empty, the system is told to map any future upper-case char-
acters into the corresponding lower-case characters.
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Finally, login is exec'd with the user's name as an argu-
ment. Additional arguments may be typed after the login
name. These are passed to login, which will place them in
the environment (see login(1)).
A check option is provided. When getty is invoked with the
-c option and file, it scans the file as if it were scanning
/etc/gettydefs and prints out the results to the standard
output. If there are any unrecognized modes or improperly
constructed entries, it reports these. If the entries are
correct, it prints out the values of the various flags. See
ioctl(2) to interpret the values. Note that some values are
added to the flags automatically.
uugetty is identical to getty but changes have been made to
support using the line for uucico, cu, and ct; that is, the
line can be used in both directions. uugetty will allow
users to login, but if the line is free, uucico, cu, or ct
can use it for dialing out. The implementation depends on
the fact that uucico, cu, and ct create lock files when dev-
ices are used. When the "open()" returns (or the first
character is read when -r option is used), the status of the
lock file indicates whether the line is being used by
uucico, cu, ct, or someone trying to login. Note that in
the -r case, several <carriage-return> characters may be
required before the login message is output. uucico trying
to login will have to be told by using the following login
script:
"" \r\d\r\d\r\d\r in:--in: . . .
where the . . . is whatever would normally be used for the
login sequence.
An entry for an intelligent modem or direct line that has a
uugetty on each end must use the -r option. (This causes
uugetty to wait to read a character before it puts out the
login message, thus preventing two uugettys from looping.)
If there is a uugetty on one end of a direct line, there
must be a uugetty on the other end as well. Here is an
/etc/inittab entry using uugetty on an intelligent modem or
direct line:
30:2:respawn:/usr/lib/uucp/uugetty -r -t 60 ttymh4 1200
uugetty should be configured on a line for which the CLOCAL
option is not the default. Terminal lines have two device
numbers, which differ by 128. In the default configuration,
CLOCAL is initially set for the lower-valued device number
and reset for the higher-numbered device number. For exam-
ple, /dev/tty1 (major number 0, minor number 1) has CLOCAL
set by default, and /dev/ttym1 (major number 0, minor numer
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129) has CLOCAL reset by default. (If the kopt(8) variable
_riscos_ttys_clocal_default is changed to "disabled" (-1),
the sense of which device number has CLOCAL set is inverted.
In the default configuration, then, uugetty and the UUCP
system should be configured to use the higher device numbers
(CLOCAL reset). For some terminal ports, such as /dev/tty1,
the corresponding "modem" special file, such as /dev/ttym1,
is created by default. For others, the special file must be
created manually, with a minor number 128 greater than the
minor number of the regular special file.
FILES
/etc/gettydefs
/etc/issue
SEE ALSO
init(1M), uucico(1M), tty(7).
ct(1), cu(1), login(1), stty(1-SysV), tip(1-BSD) in the
User's Reference Manual.
ioctl(2), gettydefs(4), inittab(4) in the Programmer's
Reference Manual.
BUGS
While getty understands simple single character quoting con-
ventions, it is not possible to quote certain special con-
trol characters used by getty. Thus, you cannot login via
getty and type a #, @, /, !, , backspace, ^U, ^D, or & as
part of your login name or arguments. getty uses them to
determine when the end of the line has been reached, which
protocol is being used, and what the erase character is.
They will always be interpreted as having their special
meaning. ct will not work when uugetty is used with an
intelligent modem such as penril or ventel.
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