gettytab(5) on openbsd

NAME

gettytab – terminal configuration database

DESCRIPTION

The gettytab file is a simplified version of the termcap(5) database used to describe terminal lines. The initial terminal login process getty(8) accesses the gettytab file each time it starts, allowing simpler reconfiguration of terminal characteristics. Each entry in the database is used to describe one class of terminals.

There is a default terminal class, default, that is used to set global defaults for all other classes. (That is, the default entry is read, then the entry for the class required is used to override particular settings.)

CAPABILITIES

Refer to termcap(5) for a description of the file layout. The default column below lists defaults obtained if there is no entry in the table obtained, nor one in the special default table.

Name	Type	Default	Description
ab	bool	false	Auto-baud speed select for the MICOM 600 port selector.
ap	bool	false	Terminal uses any parity.
bk	str	0377	Alternative end-of-line character (input break).
c0	num	unused	TTY control flags to write messages.
c1	num	unused	TTY control flags to read login name.
c2	num	unused	TTY control flags to leave terminal as.
ce	bool	false	Use CRT erase algorithm.
ck	bool	false	Use CRT kill algorithm.
cl	str	NULL	Screen clear sequence.
co	bool	false	Console; add
ds	str	‘^Y’	Delayed suspend character.
dx	bool	false	Set
ec	bool	false	Leave echo OFF.
ep	bool	false	Terminal uses even parity.
er	str	‘^?’	Erase character.
et	str	‘^D’	End of text
ev	str	NULL	Initial environment.
fl	str	‘^O’	Output flush character.
hc	bool	false	Do
hn	str	hostname	Hostname.
ht	bool	false	Terminal has real tabs.
i0	num	unused	TTY input flags to write messages.
i1	num	unused	TTY input flags to read login name.
i2	num	unused	TTY input flags to leave terminal as.
ig	bool	false	Ignore garbage characters in login name.
im	str	NULL	Initial (banner) message.
in	str	‘^C’	Interrupt character.
is	num	unused	Input speed.
kl	str	‘^U’	Kill character.
l0	num	unused	TTY local flags to write messages.
l1	num	unused	TTY local flags to read login name.
l2	num	unused	TTY local flags to leave terminal as.
lc	bool	false	Terminal has lower case.
lm	str	login:	Login prompt.
ln	str	‘^V’	``Literal next'' character.
lo	str	/usr/bin/login	Program to execute when name obtained.
mb	bool	false	Do flow control based on carrier.
nl	bool	false	Terminal has (or might have) a newline character.
np	bool	false	Terminal uses no parity (i.e., 8-bit characters).
nx	str	default	Next table (for auto speed selection).
o0	num	unused	TTY output flags to write messages.
o1	num	unused	TTY output flags to read login name.
o2	num	unused	TTY output flags to leave terminal as.
op	bool	false	Terminal uses odd parity.
os	num	unused	Output speed.
pc	str	‘\0’	Pad character.
pe	bool	false	Use printer (hard copy) erase algorithm.
pf	num	0	Delay
ps	bool	false	Line connected to a Develcon port selector.
qu	str	‘^\’	Quit character.
rp	str	‘^R’	Line retype character.
rw	bool	false	Do
sp	num	unused	Line speed (input and output).
su	str	‘^Z’	Suspend character.
tc	str	none	Table continuation.
to	num	0	Timeout (seconds).
tt	str	NULL	Terminal type (for environment).
ub	bool	false	Do unbuffered output (of prompts etc).
uc	bool	false	Terminal is known upper case only.
we	str	‘^W’	Word erase character.
xc	bool	false	Do
xf	str	‘^S’	XOFF
xn	str	‘^Q’	XON

The following capabilities are no longer supported by getty(8):

cb	bool	false	Use CRT backspace mode.
f0	num	unused	TTY mode flags to write messages.
f1	num	unused	TTY mode flags to read login name.
f2	num	unused	TTY mode flags to leave terminal as.
he	str	NULL	Hostname editing string.

The following delay capabilities are no longer supported by getty(8):

bd	num	Backspace delay.
cd	num	Carriage-return delay.
fd	num	Form-feed (vertical motion) delay.
nd	num	Newline (line-feed) delay.
td	num	Tab delay.

If no line speed is specified, speed will not be altered from that which prevails when getty(8) is entered. Specifying an input or output speed will override line speed for stated direction only.

Terminal modes to be used for the output of the message and for input of the login name, and to leave the terminal set as upon completion, are derived from the boolean flags specified. If the derivation should prove inadequate, any (or all) of these three may be overridden with one of the c0, c1, c2, i0, i1, i2, l0, l1, l2, o0, o1, or o2 numeric specifications, which can be used to specify (usually in octal, with a leading ‘0’) the exact values of the flags. These flags correspond to the termios c_cflag, c_iflag, c_lflag, and c_oflag fields, respectively. Each of these sets must be completely specified to be effective.

Should getty(8) receive a null character (presumed to indicate a line break) it will restart using the table indicated by the nx entry. If there is none, it will re-use its original table.

The cl screen clear string may be preceded by a (decimal) number of milliseconds of delay required (a la termcap(5)). This delay is simulated by repeated use of the pad character pc.

The initial message and login message( im and lm) may include any of the following character sequences, which expand to information about the environment in which getty(8) is running:

%d: The current date.
%h: The hostname of the machine, which is normally obtained from the system using gethostname(3), but may also be overridden by the hn table entry.
%t: The TTY name.
%m, %r, %s, %v: The type of machine, release of the operating system, name of the operating system, and version of the kernel, respectively, as returned by uname(3).
%%: A ‘%’ character.

When getty(8) executes the login process given in the lo string (usually /usr/bin/login), it will have set the environment to include the terminal type, as indicated by the tt string (if it exists). The ev string can be used to enter additional data into the environment. It is a list of comma-separated strings, each of which will presumably be of the form name=value.

If a non-zero timeout is specified with to, then getty(8) will exit within the indicated number of seconds, either having received a login name and passed control to login(1), or having received an alarm signal and exited. This may be useful to hangup dial in lines.

Output from getty(8) is even parity unless op or np is specified. The op string may be specified with ap to allow any parity on input, but generate odd parity output. Note: this only applies while getty(8) is being run; terminal driver limitations prevent a more complete implementation. getty(8) does not check parity of input characters in RAW mode.

FILES

/etc/gettytab: Default location of the database file.

HISTORY

The gettytab file format appeared in 4.2BSD.

BUGS

The special characters (erase, kill, etc.) are reset to system defaults by login(1).

The termcap(5) format is horrid; something more rational should have been chosen.

gettytab(5)