xref: /freebsd/libexec/getty/gettytab.5 (revision 0d66206fff44f864ea8a4b220c3a53b4caa959a0)
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28.\"     from: @(#)gettytab.5	8.4 (Berkeley) 4/19/94
29.\" $FreeBSD$
30.\" "
31.Dd September 29, 2022
32.Dt GETTYTAB 5
33.Os
34.Sh NAME
35.Nm gettytab
36.Nd terminal configuration data base
37.Sh SYNOPSIS
38.Nm
39.Sh DESCRIPTION
40The
41.Nm
42file
43is a simplified version of the
44.Xr termcap 5
45data base
46used to describe terminal lines.
47The initial terminal login process
48.Xr getty 8
49accesses the
50.Nm
51file each time it starts, allowing simpler
52reconfiguration of terminal characteristics.
53Each entry in the data base
54is used to describe one class of terminals.
55.Pp
56There is a default terminal class,
57.Va default ,
58that is used to set global defaults for all other classes.
59(That is, the
60.Va default
61entry is read, then the entry for the class required
62is used to override particular settings.)
63.Sh CAPABILITIES
64Refer to
65.Xr termcap 5
66for a description of the file layout.
67The
68.Va default
69column below lists defaults obtained if there is
70no entry in the table obtained, nor one in the special
71.Va default
72table.
73.Bl -column Name Type /usr/bin/login
74.It Sy "Name	Type	Default	Description"
75.It "ac	str	unused	expect-send chat script for modem answer"
76.It "al	str	unused	user to auto-login instead of prompting"
77.It "ap	bool	false	terminal uses any parity"
78.It "bk	str	0377	alternate end of line character (input break)"
79.It "c0	num	unused	tty control flags to write messages"
80.It "c1	num	unused	tty control flags to read login name"
81.It "c2	num	unused	tty control flags to leave terminal as"
82.It "ce	bool	false	use crt erase algorithm"
83.It "ck	bool	false	use crt kill algorithm"
84.It "cl	str" Ta Dv NULL
85.Ta No "screen clear sequence"
86.It "co	bool	false	console - add"
87.Ql \en
88after login prompt
89.It "ct	num	10	chat timeout for"
90.Va \&ac
91and
92.Va \&ic
93scripts
94.It "dc	num	0	chat debug bitmask"
95.It "de	num	0	delay secs and flush input before writing first prompt"
96.It "df	str	%+	the" Xr strftime 3 "format used for \&%d in the banner message"
97.It "ds	str" Ta So Li ^Y
98.Sc Ta No "delayed suspend character"
99.It "dx	bool	false	set"
100.Dv DECCTLQ
101.It "ec	bool	false	leave echo"
102.Em OFF
103.It "ep	bool	false	terminal uses even parity"
104.It "er	str" Ta So Li ^?
105.Sc Ta No "erase character"
106.It "et	str" Ta So Li ^D
107.Sc Ta No "end of text"
108.Pq Dv EOF
109character
110.It "ev	str" Ta Dv NULL
111.Ta No "initial environment"
112.It "fl	str" Ta So Li ^O
113.Sc Ta No "output flush character"
114.It "hc	bool	false	do"
115.Em NOT
116hangup line on last close
117.It "he	str" Ta Dv NULL
118.Ta No "hostname editing regular expression"
119.It "hn	str	hostname	hostname"
120.It "ht	bool	false	terminal has real tabs"
121.It "hw	bool	false	do cts/rts hardware flow control"
122.It "i0	num	unused	tty input flags to write messages"
123.It "i1	num	unused	tty input flags to read login name"
124.It "i2	num	unused	tty input flags to leave terminal as"
125.It "ic	str	unused	expect-send chat script for modem initialization"
126.It "if	str	unused	display named file before prompt, like /etc/issue"
127.It "ig	bool	false	ignore garbage characters in login name"
128.It "im	str" Ta Dv NULL
129.Ta No "initial (banner) message"
130.It "iM	str" Ta Dv NULL
131.Ta No "execute named file to generate initial (banner) message"
132.It "in	str" Ta So Li ^C
133.Sc Ta No "interrupt character"
134.It "is	num	unused	input speed"
135.It "kl	str" Ta So Li ^U
136.Sc Ta No "kill character"
137.It "l0	num	unused	tty local flags to write messages"
138.It "l1	num	unused	tty local flags to read login name"
139.It "l2	num	unused	tty local flags to leave terminal as"
140.It "lm	str	login:	login prompt"
141.It "ln	str" Ta So Li ^V
142.Sc Ta No "``literal next'' character"
143.It "lo	str" Ta Pa /usr/bin/login
144.Ta No "program to exec when name obtained"
145.It "mb	bool	false	do flow control based on carrier"
146.It "nc	bool	false	terminal does not supply carrier (set clocal)"
147.It "nl	bool	false	terminal has (or might have) a newline character"
148.It "np	bool	false	terminal uses no parity (i.e., 8-bit characters)"
149.It "nx	str	default	next table (for auto speed selection)"
150.It "o0	num	unused	tty output flags to write messages"
151.It "o1	num	unused	tty output flags to read login name"
152.It "o2	num	unused	tty output flags to leave terminal as"
153.It "op	bool	false	terminal uses odd parity"
154.It "os	num	unused	output speed"
155.It "pc	str" Ta So Li \e0
156.Sc Ta No "pad character"
157.It "pe	bool	false	use printer (hard copy) erase algorithm"
158.It "pf	num	0	delay"
159between first prompt and following flush (seconds)
160.It "pl	bool	false	start PPP login program unconditionally if"
161.Va \&pp
162is specified
163.It "pp	str	unused	PPP login program"
164.It "ps	bool	false	line connected to a"
165.Tn MICOM
166port selector
167.It "qu	str" Ta So Li \&^\e
168.Sc Ta No "quit character"
169.It "rp	str" Ta So Li ^R
170.Sc Ta No "line retype character"
171.It "rt	num	unused	ring timeout when using"
172.Va \&ac
173.It "rw	bool	false	do"
174.Em NOT
175use raw for input, use cbreak
176.It "sp	num	unused	line speed (input and output)"
177.It "su	str" Ta So Li ^Z
178.Sc Ta No "suspend character"
179.It "tc	str	none	table continuation"
180.It "to	num	0	timeout (seconds)"
181.It "tt	str" Ta Dv NULL
182.Ta No "terminal type (for environment)"
183.It "ub	bool	false	do unbuffered output (of prompts etc)"
184.It "we	str" Ta So Li ^W
185.Sc Ta No "word erase character"
186.It "xc	bool	false	do"
187.Em NOT
188echo control chars as
189.Ql ^X
190.It "xf	str" Ta So Li ^S Sc Ta Dv XOFF
191(stop output) character
192.It "xn	str" Ta So Li ^Q Sc Ta Dv XON
193(start output) character
194.It "Lo	str	C	the locale name used for \&%d in the banner message"
195.El
196.Pp
197The following capabilities are no longer supported by
198.Xr getty 8 :
199.Bl -column Name Type /usr/bin/login
200.It "bd	num	0	backspace delay"
201.It "cb	bool	false	use crt backspace mode"
202.It "cd	num	0	carriage-return delay"
203.It "f0	num	unused	tty mode flags to write messages"
204.It "f1	num	unused	tty mode flags to read login name"
205.It "f2	num	unused	tty mode flags to leave terminal as"
206.It "fd	num	0	form-feed (vertical motion) delay"
207.It "lc	bool	false	terminal has lower case"
208.It "nd	num	0	newline (line-feed) delay"
209.It "uc	bool	false	terminal is known upper case only"
210.El
211.Pp
212If no line speed is specified, speed will not be altered
213from that which prevails when getty is entered.
214Specifying an input or output speed will override
215line speed for stated direction only.
216.Pp
217Terminal modes to be used for the output of the message,
218for input of the login name,
219and to leave the terminal set as upon completion,
220are derived from the boolean flags specified.
221If the derivation should prove inadequate,
222any (or all) of these three may be overridden
223with one of the
224.Va \&c0 ,
225.Va \&c1 ,
226.Va \&c2 ,
227.Va \&i0 ,
228.Va \&i1 ,
229.Va \&i2 ,
230.Va \&l0 ,
231.Va \&l1 ,
232.Va \&l2 ,
233.Va \&o0 ,
234.Va \&o1 ,
235or
236.Va \&o2
237numeric specifications, which can be used to specify
238(usually in octal, with a leading '0')
239the exact values of the flags.
240These flags correspond to the termios
241.Va c_cflag ,
242.Va c_iflag ,
243.Va c_lflag ,
244and
245.Va c_oflag
246fields, respectively.
247Each these sets must be completely specified to be effective.
248.Pp
249Should
250.Xr getty 8
251receive a null character
252(presumed to indicate a line break)
253it will restart using the table indicated by the
254.Va \&nx
255entry.
256If there is none, it will re-use its original table.
257.Pp
258Delays are specified in milliseconds, the nearest possible
259delay available in the tty driver will be used.
260Should greater certainty be desired, delays
261with values 0, 1, 2, and 3 are interpreted as
262choosing that particular delay algorithm from the driver.
263.Pp
264The
265.Va \&cl
266screen clear string may be preceded by a (decimal) number
267of milliseconds of delay required (a la termcap).
268This delay is simulated by repeated use of the pad character
269.Va \&pc .
270.Pp
271The initial message, login message, and initial file;
272.Va \&im ,
273.Va \&lm
274and
275.Va \&if
276may include any of the following character sequences, which expand to
277information about the environment in which
278.Xr getty 8
279is running.
280.Bl -tag -offset indent -width \&%xxxxxxxxxxxxxx
281.It \&%d
282The current date and time formatted according to the
283.Va \&Lo
284and
285.Va \&df
286strings.
287.It \&%h
288The hostname of the machine, which is normally obtained from the
289system using
290.Xr gethostname 3 ,
291but may also be overridden by the
292.Va \&hn
293table entry.
294In either case it may be edited with the
295.Va \&he
296POSIX
297.Dq extended
298regular expression, which is matched against the hostname.
299If there are no parenthesized subexpressions in the pattern,
300the entire matched string is used as the final hostname;
301otherwise, the first matched subexpression is used instead.
302If the pattern does not match, the original hostname is not modified.
303.It \&%t
304The tty name.
305.It "\&%m, \&%r, \&%s, \&%v"
306The type of machine, release of the operating system, name of the
307operating system, and version of the kernel, respectively, as
308returned by
309.Xr uname 3 .
310.It \&%%
311A
312.Dq %
313character.
314.El
315.Pp
316When getty execs the login process, given
317in the
318.Va \&lo
319string (usually
320.Dq Pa /usr/bin/login ) ,
321it will have set
322the environment to include the terminal type, as indicated
323by the
324.Va \&tt
325string (if it exists).
326The
327.Va \&ev
328string, can be used to enter additional data into
329the environment.
330It is a list of comma separated strings, each of which
331will presumably be of the form
332.Li name=value .
333.Pp
334If a non-zero timeout is specified, with
335.Va \&to ,
336then getty will exit within the indicated
337number of seconds, either having
338received a login name and passed control
339to
340.Xr login 1 ,
341or having received an alarm signal, and exited.
342This may be useful to hangup dial in lines.
343.Pp
344Output from
345.Xr getty 8
346is even parity unless
347.Va \&op
348or
349.Va \&np
350is specified.
351The
352.Va \&op
353string
354may be specified with
355.Va \&ap
356to allow any parity on input, but generate odd parity output.
357Note: this only applies while getty is being run,
358terminal driver limitations prevent a more complete
359implementation.
360The
361.Xr getty 8
362utility does not check parity of input characters in
363.Dv RAW
364mode.
365.Pp
366If a
367.Va \&pp
368string is specified and a PPP link bring-up sequence is recognized,
369getty will invoke the program referenced by the
370.Va \&pp
371option.
372This can be used to handle incoming PPP calls.
373If the
374.Va \&pl
375option is true as well,
376.Xr getty 8
377will skip the user name prompt and the PPP detection phase, and will
378invoke the program specified by
379.Va \&pp
380instantly.
381.Pp
382.Nm Getty
383provides some basic intelligent modem handling by providing a chat
384script feature available via two capabilities:
385.Pp
386.Bl -tag -offset indent -width \&xxxxxxxx -compact
387.It ic
388Chat script to initialize modem.
389.It ac
390Chat script to answer a call.
391.El
392.Pp
393A chat script is a set of expect/send string pairs.
394When a chat string starts,
395.Nm getty
396will wait for the first string, and if it finds it, will send the
397second, and so on.
398Strings specified are separated by one or more tabs or spaces.
399Strings may contain standard ASCII characters and special 'escapes',
400which consist of a backslash character followed by one or more
401characters which are interpreted as follows:
402.Pp
403.Bl -tag -offset indent -width \&xxxxxxxx -compact
404.It \ea
405bell character.
406.It \eb
407backspace.
408.It \en
409newline.
410.It \ee
411escape.
412.It \ef
413formfeed.
414.It \ep
415half-second pause.
416.It \er
417carriage return.
418.It \eS , \es
419space character.
420.It \et
421tab.
422.It \exNN
423hexadecimal byte value.
424.It \e0NNN
425octal byte value.
426.El
427.Pp
428Note that the
429.Ql \ep
430sequence is only valid for send strings and causes a half-second
431pause between sending the previous and next characters.
432Hexadecimal values are, at most, 2 hex digits long, and octal
433values are a maximum of 3 octal digits.
434.Pp
435The
436.Va \&ic
437chat sequence is used to initialize a modem or similar device.
438A typical example of an init chat script for a modem with a
439hayes compatible command set might look like this:
440.Pp
441.Dl :ic="" ATE0Q0V1\er OK\er ATS0=0\er OK\er:
442.Pp
443This script waits for nothing (which always succeeds), sends
444a sequence to ensure that the modem is in the correct mode
445(suppress command echo, send responses in verbose mode),
446and then disables auto-answer.
447It waits for an "OK" response before it terminates.
448The init sequence is used to check modem responses to ensure that
449the modem is functioning correctly.
450If the init script fails to complete,
451.Nm getty
452considers this to be fatal, and results in an error logged via
453.Xr syslogd 8 ,
454and exiting.
455.Pp
456Similarly, an answer chat script is used to manually answer the
457phone in response to (usually) a "RING".
458When run with an answer script,
459.Nm getty
460opens the port in non-blocking mode, clears any extraneous input
461and waits for data on the port.
462As soon as any data is available, the answer chat script is
463started and scanned for a string, and responds according to
464the answer chat script.
465With a hayes compatible modem, this would normally look something
466like:
467.Pp
468.Dl :ac=RING\er ATA\er CONNECT:
469.Pp
470This causes the modem to answer the call via the "ATA" command,
471then scans input for a "CONNECT" string.
472If this is received before a
473.Va \&ct
474timeout, then a normal login sequence commences.
475.Pp
476The
477.Va \&ct
478capability specifies a timeout for all send and expect strings.
479This timeout is set individually for each expect wait and send
480string and must be at least as long as the time it takes for
481a connection to be established between a remote and local
482modem (usually around 10 seconds).
483.Pp
484In most situations, you will want to flush any additional
485input after the connection has been detected, and the
486.Va \&de
487capability may be used to do that, as well as delay for a
488short time after the connection has been established during
489which all of the connection data has been sent by the modem.
490.Sh SEE ALSO
491.Xr login 1 ,
492.Xr gethostname 3 ,
493.Xr uname 3 ,
494.Xr termcap 5 ,
495.Xr getty 8
496.Sh HISTORY
497The
498.Nm
499file format appeared in
500.Bx 4.2 .
501.Sh BUGS
502The special characters (erase, kill, etc.) are reset to system defaults
503by
504.Xr login 1 .
505In
506.Em all
507cases, '#' or '^H' typed in a login name will be treated as
508an erase character, and '@' will be treated as a kill character.
509.Pp
510The delay stuff is a real crock.
511Apart form its general lack of flexibility, some
512of the delay algorithms are not implemented.
513The terminal driver should support sane delay settings.
514.Pp
515The
516.Xr termcap 5
517format is horrid, something more rational should
518have been chosen.
519