xref: /freebsd/share/termcap/termcap.5 (revision ce834215a70ff69e7e222827437116eee2f9ac6f)
1.\" Copyright (c) 1985, 1991, 1993, 1994
2.\"	The Regents of the University of California.  All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\"    notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\" 3. All advertising materials mentioning features or use of this software
13.\"    must display the following acknowledgement:
14.\"	This product includes software developed by the University of
15.\"	California, Berkeley and its contributors.
16.\" 4. Neither the name of the University nor the names of its contributors
17.\"    may be used to endorse or promote products derived from this software
18.\"    without specific prior written permission.
19.\"
20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30.\" SUCH DAMAGE.
31.\"
32.\"     @(#)termcap.5	8.3 (Berkeley) 4/16/94
33.\"	$Id: termcap.5,v 1.5 1997/02/22 13:56:39 peter Exp $
34.\"
35.Dd April 16, 1994
36.Dt TERMCAP 5
37.Os BSD 3
38.Sh NAME
39.Nm termcap
40.Nd terminal capability data base
41.Sh SYNOPSIS
42.Nm
43.Sh DESCRIPTION
44The
45.Nm
46file
47is a data base describing terminals,
48used,
49for example,
50by
51.Xr \&vi 1
52and
53.Xr curses 3 .
54Terminals are described in
55.Nm
56by giving a set of capabilities that they have and by describing
57how operations are performed.
58Padding requirements and initialization sequences
59are included in
60.Nm Ns .
61.Pp
62Entries in
63.Nm
64consist of a number of `:'-separated fields.
65The first entry for each terminal gives the names that are known for the
66terminal, separated by `|' characters.
67The first name given is the most common abbreviation for the terminal.
68The last name given should be a long name fully identifying the terminal,
69and all others are understood as synonyms for the terminal name.
70All names but the last should be in lower case and contain no blanks;
71the last name may well contain upper case characters and blanks for
72readability.
73.Pp
74Terminal names (except for the last, verbose entry)
75should be chosen using the following conventions.
76The particular piece of hardware making up the terminal
77should have a root name chosen, thus
78.Dq hp2621
79This name should not contain hyphens.
80Modes that the hardware can be in
81or user preferences
82should be indicated by appending a hyphen and an indicator of the mode.
83Therefore, a
84.Dq vt100
85in 132-column mode would be
86.Dq vt100-w .
87The following suffixes should be used where possible:
88.Pp
89.Bd -filled -offset indent
90.Bl -column indent "With automatic margins (usually default)xx"
91.Sy Suffix	Meaning	Example
92-w	Wide mode (more than 80 columns)	vt100-w
93-am	With automatic margins (usually default)	vt100-am
94-nam	Without automatic margins	vt100-nam
95.Pf \- Ar n Ta No "Number of lines on screen	aaa-60"
96-na	No arrow keys (leave them in local)	concept100-na
97.Pf \- Ar \&np Ta No "Number of pages of memory	concept100-4p"
98-rv	Reverse video	concept100-rv
99.El
100.Ed
101.Sh CAPABILITIES
102The characters in the
103.Em Notes
104function
105field in the table have the following meanings
106(more than one may apply to a capability):
107.Pp
108.Bd -unfilled -offset indent
109N	indicates numeric parameter(s)
110P	indicates that padding may be specified
111*	indicates that padding may be based on the number of lines affected
112o	indicates capability is obsolete
113.Ed
114.Pp
115.Dq Obsolete
116capabilities have no
117.Em terminfo
118equivalents,
119since they were considered useless,
120or are subsumed by other capabilities.
121New software should not rely on them at all.
122.Pp
123The following section is not complete, to get a more complete listing
124look in
125.Pa /usr/src/share/termcap/terminfo_extensions.doc .
126.Pp
127.Bl -column indent indent indent
128.Sy Name	Type	Notes	Description
129functions
130.It "ae	str	(P)	End alternate character set."
131.It AL	str	(NP*)	Add
132.Em n
133new blank lines
134.It "al	str	(P*)	Add new blank line."
135.It "am	bool		Terminal has automatic margins."
136.It "as	str	(P)	Start alternate character set."
137.It "bc	str	(o)	Backspace if not."
138.Sy \&^H .
139.It "bl	str	(P)	Audible signal (bell)."
140.It "bs	bool	(o)	Terminal can backspace with"
141.Sy \&^H .
142.It "bt	str	(P)	Back tab."
143.It "bw	bool	" Ta Sy \&le
144(backspace) wraps from column 0 to last column.
145.It "CC	str		Terminal settable command character in prototype."
146.It "cd	str	(P*)	Clear to end of display."
147.It "ce	str	(P)	Clear to end of line."
148.It "ch	str	(NP)	Set cursor column (horizontal position)."
149.It "cl	str	(P*)	Clear screen and home cursor."
150.It "CM	str	(NP)	Memory-relative cursor addressing."
151.It "cm	str	(NP)	Screen-relative cursor motion."
152.It "co	num		Number of columns in a line (See"
153.Sx BUGS
154section below).
155.It "cr	str	(P)	Carriage return."
156.It "cs	str	(NP)	Change scrolling region (VT100)."
157.It "ct	str	(P)	Clear all tab stops."
158.It "cv	str	(NP)	Set cursor row (vertical position)."
159.It "da	bool		Display may be retained above the screen."
160.It "dB	num	(o)	Milliseconds of"
161.Sy \&bs
162delay needed (default 0).
163.It "db	bool		Display may be retained below the screen."
164.It "DC	str	(NP*)	Delete"
165.Em n
166characters.
167.It "dC	num	(o)	Milliseconds of"
168.Sy \&cr
169delay needed (default 0).
170.It "dc	str	(P*)	Delete character."
171.It "dF	num	(o)	Milliseconds of"
172.Sy \&ff
173delay needed (default 0).
174.It "DL	str	(NP*)	Delete"
175.Ar n
176lines.
177.It "dl	str	(P*)	Delete line."
178.It "dm	str		Enter delete mode."
179.It "dN	num	(o)	Milliseconds of
180.Sy \&nl
181delay needed (default 0).
182.It "DO	str	(NP*)	Move cursor down:
183.Ar n
184lines.
185.It "do	str		Down one line."
186.It "ds	str		Disable status line."
187.It "dT	num	(o)	Milliseconds of horizontal tab delay needed (default 0)."
188.It "dV	num	(o)	Milliseconds of vertical tab delay needed (default 0)."
189.It "ec	str	(NP)	Erase"
190.Ar n
191characters.
192.It "ed	str		End delete mode."
193.It "ei	str		End insert mode."
194.It "eo	bool		Can erase overstrikes with a blank."
195.It "EP	bool	(o)	Even parity."
196.It "es	bool		Escape can be used on the status line."
197.It "ff	str	(P*)	Hardcopy terminal page eject."
198.It "fs	str		Return from status line."
199.It "gn	bool		Generic line type, for example dialup, switch)."
200.It "hc	bool		Hardcopy terminal."
201.It "HD	bool	(o)	Half-duplex."
202.It "hd	str		Half-line down (forward 1/2 linefeed)."
203.It "ho	str	(P)	Home cursor."
204.It "hs	bool		Has extra"
205.Dq status line .
206.It "hu	str		Half-line up (reverse 1/2 linefeed)."
207.It "hz	bool		Cannot print ``~'' (Hazeltine)."
208.It "i1-i3	str		Terminal initialization strings"
209.Pf ( Xr terminfo
210only)
211.It "IC	str	(NP*)	Insert"
212.Ar n
213blank characters.
214.It "ic	str	(P*)	Insert character."
215.It "if	str		Name of file containing initialization string."
216.It "im	str		Enter insert mode."
217.It "in	bool		Insert mode distinguishes nulls."
218.It "iP	str		Pathname of program for initialization"
219.Pf ( Xr terminfo
220only).
221.It "ip	str	(P*)	Insert pad after character inserted."
222.It "is	str		Terminal initialization string"
223.Pf ( Nm termcap
224only).
225.It "it	num		Tabs initially every"
226.Ar n
227positions.
228.It "K1	str		Sent by keypad upper left."
229.It "K2	str		Sent by keypad upper right."
230.It "K3	str		Sent by keypad center."
231.It "K4	str		Sent by keypad lower left."
232.It "K5	str		Sent by keypad lower right."
233.It "k0-k9	str		Sent by function keys 0-9."
234.It "kA	str		Sent by insert-line key."
235.It "ka	str		Sent by clear-all-tabs key."
236.It "kb	str		Sent by backspace key."
237.It "kC	str		Sent by clear-screen or erase key."
238.It "kD	str		Sent by delete-character key."
239.It "kd	str		Sent by down-arrow key."
240.It "kE	str		Sent by clear-to-end-of-line key."
241.It "ke	str		Out of"
242.Dq keypad transmit
243mode.
244.It "kF	str		Sent by scroll-forward/down key."
245.It "kH	str		Sent by home-down key."
246.It "kh	str		Sent by home key."
247.It "kI	str		Sent by insert-character or enter-insert-mode key."
248.It "kL	str		Sent by delete-line key."
249.It "kl	str		Sent by left-arrow key."
250.It "kM	str		Sent by insert key while in insert mode."
251.It "km	bool		Has a"
252.Dq meta
253key (shift, sets parity bit).
254.It "kN	str		Sent by next-page key."
255.It "kn	num	(o)	Number of function"
256.Pq Sy \&k\&0 Ns \- Ns Sy \&k\&9
257keys (default 0).
258.It "ko	str	(o)	Termcap entries for other non-function keys."
259.It "kP	str		Sent by previous-page key."
260.It "kR	str		Sent by scroll-backward/up key."
261.It "kr	str		Sent by right-arrow key."
262.It "kS	str		Sent by clear-to-end-of-screen key."
263.It "ks	str		Put terminal in"
264.Dq keypad transmit
265mode.
266.It "kT	str		Sent by set-tab key."
267.It "kt	str		Sent by clear-tab key."
268.It "ku	str		Sent by up-arrow key."
269.It "l0-l9	str		Labels on function keys if not"
270.Dq \&f Ns Em n .
271.It "LC	bool	(o)	Lower-case only."
272.It "LE	str	(NP)	Move cursor left"
273.Ar n
274positions.
275.It "le	str	(P)	Move cursor left one position."
276.It "li	num		Number of lines on screen or page (See"
277.Sx BUGS
278section below)
279.It "ll	str		Last line, first column
280.It "lm	num		Lines of memory if >" Sy \&li
281(0 means varies).
282.It "ma	str	(o)	Arrow key map (used by"
283.Xr \&vi
284version 2 only).
285.It "mb	str		Turn on blinking attribute."
286.It "md	str		Turn on bold (extra bright) attribute."
287.It "me	str		Turn off all attributes."
288.It "mh	str		Turn on half-bright attribute."
289.It "mi	bool		Safe to move while in insert mode."
290.It "mk	str		Turn on blank attribute (characters invisible)."
291.It "ml	str	(o)	Memory lock on above cursor."
292.It "mm	str		Turn on"
293.Dq meta mode
294(8th bit).
295.It "mo	str		Turn off"
296.Dq meta mode .
297.It "mp	str		Turn on protected attribute."
298.It "mr	str		Turn on reverse-video attribute."
299.It "ms	bool		Safe to move in standout modes."
300.It "mu	str	(o)	Memory unlock (turn off memory lock)."
301.It "nc	bool	(o)	No correctly-working"
302.Sy \&cr
303(Datamedia 2500, Hazeltine 2000).
304.It "nd	str		Non-destructive space (cursor right)."
305.It "NL	bool	(o)" Ta Sy \&\en No "is newline, not line feed."
306.It "nl	str	(o)	Newline character if not" Sy \en .
307.It "ns	bool	(o)	Terminal is a" Tn CRT No "but doesn't scroll."
308.It "nw	str	(P)	Newline"
309.Po behaves like \&
310.Sy \&cr
311followed by
312.Sy \&do
313.Pc .
314.It "OP	bool	(o)	Odd parity."
315.It "os	bool		Terminal overstrikes."
316.It "pb	num		Lowest baud where delays are required."
317.It "pc	str		Pad character
318.Pq default Tn NUL .
319.It "pf	str		Turn off the printer."
320.It "pk	str		Program function key"
321.Em n
322to type string
323.Em s
324.Pf ( Xr terminfo
325only).
326.It "pl	str		Program function key"
327.Em n
328to execute string
329.Em s
330.Pf ( Xr terminfo
331only).
332.It "pO	str	(N)	Turn on the printer for"
333.Em n
334bytes.
335.It "po	str		Turn on the printer."
336.It "ps	str		Print contents of the screen."
337.It "pt	bool	(o)	Has hardware tabs"
338.Pq may need to be set with Sy \&is .
339.It "px	str		Program function key"
340.Em n
341to transmit string
342.Em s
343.Pf ( Xr terminfo
344only).
345.It "r1-r3	str		Reset terminal completely to sane modes"
346.Pf ( Xr terminfo
347only).
348.It "rc	str	(P)	Restore cursor to position of last"
349.Sy \&sc .
350.It "rf	str		Name of file containing reset codes."
351.It "RI	str	(NP)	Move cursor right"
352.Em n
353positions.
354.It "rp	str	(NP*)	Repeat character"
355.Em c n
356times.
357.It "rs	str		Reset terminal completely to sane modes"
358.Pf ( Nm termcap
359only).
360.It "sa	str	(NP)	Define the video attributes."
361.It "sc	str	(P)	Save cursor position."
362.It "se	str		End standout mode."
363.It "SF	str	(NP*)	Scroll forward"
364.Em n
365lines.
366.It "sf	str	(P)	Scroll text up."
367.It "sg	num		Number of garbage chars left by"
368.Sy \&so
369or
370.Sy \&se
371(default 0).
372.It "so	str		Begin standout mode."
373.It "SR	str	(NP*)	Scroll backward"
374.Em n
375lines.
376.It "sr	str	(P)	Scroll text down."
377.It "st	str		Set a tab in all rows, current column."
378.It "ta	str	(P)	Tab to next 8-position hardware tab stop."
379.It "tc	str		Entry of similar terminal \- must be last."
380.It "te	str		String to end programs that use"
381.Nm Ns .
382.It "ti	str		String to begin programs that use"
383.Nm Ns .
384.It "ts	str	(N)	Go to status line, column"
385.Em n .
386.It "UC	bool	(o)	Upper-case only."
387.It "uc	str		Underscore one character and move past it."
388.It "ue	str		End underscore mode."
389.It "ug	num		Number of garbage chars left by"
390.Sy \&us
391or
392.Sy \&ue
393(default 0).
394.It "ul	bool		Underline character overstrikes."
395.It "UP	str	(NP*)	Move cursor up"
396.Em n
397lines.
398.It "up	str		Upline (cursor up)."
399.It "us	str		Start underscore mode."
400.It "vb	str		Visible bell (must not move cursor)."
401.It "ve	str		Make cursor appear normal (undo"
402.Sy \&vs Ns / Ns Sy \&vi ) .
403.It "vi	str		Make cursor invisible."
404.It "vs	str		Make cursor very visible."
405.It "vt	num		Virtual terminal number (not supported on all systems)."
406.It "wi	str	(N)	Set current window."
407.It "ws	num		Number of columns in status line."
408.It "xb	bool		Beehive"
409.Pf ( "f1=" Ns Dv ESC ,
410.Pf "f2=" Sy \&^C ) .
411.It "xn	bool		Newline ignored after 80 cols (Concept)."
412.It "xo	bool		Terminal uses xoff/xon"
413.Pq Dv DC3 Ns / Ns Dv DC1
414handshaking.
415.It "xr	bool	(o)	Return acts like"
416.Sy "ce cr nl"
417(Delta Data).
418.It "xs	bool		Standout not erased by overwriting (Hewlett-Packard)."
419.It "xt	bool		Tabs ruin, magic"
420.SY \&so
421char (Teleray 1061).
422.It "xx	bool	(o)	Tektronix 4025 insert-line."
423.El
424.Ss A Sample Entry
425The following entry, which describes the Concept\-100, is among the more
426complex entries in the
427.Nm
428file as of this writing.
429.Pp
430.Bd -literal
431ca\||\|concept100\||\|c100\||\|concept\||\|c104\||\|concept100-4p\||\|HDS Concept\-100:\e
432	:al=3*\eE^R:am:bl=^G:cd=16*\eE^C:ce=16\eE^U:cl=2*^L:cm=\eEa%+ %+ :\e
433	:co#80:.cr=9^M:db:dc=16\eE^A:dl=3*\eE^B:do=^J:ei=\eE\e200:eo:im=\eE^P:in:\e
434	:ip=16*:is=\eEU\eEf\eE7\eE5\eE8\eEl\eENH\eEK\eE\e200\eEo&\e200\eEo\e47\eE:k1=\eE5:\e
435	:k2=\eE6:k3=\eE7:kb=^h:kd=\eE<:ke=\eEx:kh=\eE?:kl=\eE>:kr=\eE=:ks=\eEX:\e
436	:ku=\eE;:le=^H:li#24:mb=\eEC:me=\eEN\e200:mh=\eEE:mi:mk=\eEH:mp=\eEI:\e
437	:mr=\eED:nd=\eE=:pb#9600:rp=0.2*\eEr%.%+ :se=\eEd\eEe:sf=^J:so=\eEE\eED:\e
438	:.ta=8\et:te=\eEv    \e200\e200\e200\e200\e200\e200\eEp\er\en:\e
439	:ti=\eEU\eEv  8p\eEp\er:ue=\eEg:ul:up=\eE;:us=\eEG:\e
440	:vb=\eEk\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\eEK:\e
441	:ve=\eEw:vs=\eEW:vt#8:xn:\e
442	:bs:cr=^M:dC#9:dT#8:nl=^J:ta=^I:pt:
443.Ed
444.Pp
445Entries may continue onto multiple lines by giving a \e as the last
446character of a line, and empty fields
447may be included for readability (here between the last field on a line
448and the first field on the next).
449Comments may be included on lines beginning with
450.Dq # .
451.Ss Types of Capabilities
452Capabilities in
453.Nm
454are of three types: Boolean capabilities,
455which indicate particular features that the terminal has;
456numeric capabilities,
457giving the size of the display or the size of other attributes;
458and string capabilities,
459which give character sequences that can be used to perform particular
460terminal operations.
461All capabilities have two-letter codes.
462For instance, the fact that
463the Concept has
464.Em automatic margins
465(an automatic return and linefeed
466when the end of a line is reached) is indicated by the Boolean capability
467.Sy \&am .
468Hence the description of the Concept includes
469.Sy \&am .
470.Pp
471Numeric capabilities are followed by the character `#' then the value.
472In the example above
473.Sy \&co ,
474which indicates the number of columns the display has,
475gives the value `80' for the Concept.
476.Pp
477Finally, string-valued capabilities, such as
478.Sy \&ce
479(clear-to-end-of-line
480sequence) are given by the two-letter code, an `=', then a string
481ending at the next following `:'.
482A delay in milliseconds may appear after
483the `=' in such a capability,
484which causes padding characters to be supplied by
485.Xr tputs
486after the remainder of the string is sent to provide this delay.
487The delay can be either a number,
488such as `20', or a number followed by
489an `*',
490such as `3*'.
491An `*' indicates that the padding required is proportional
492to the number of lines affected by the operation, and the amount given is
493the per-affected-line padding required.
494(In the case of insert-character,
495the factor is still the number of
496.Em lines
497affected;
498this is always 1 unless the terminal has
499.Sy \&in
500and the software uses it.)
501When an `*' is specified, it is sometimes useful to give a delay of the form
502`3.5' to specify a delay per line to tenths of milliseconds.
503(Only one decimal place is allowed.)
504.Pp
505A number of escape sequences are provided in the string-valued capabilities
506for easy encoding of control characters there.
507.Sy \&\eE
508maps to an
509.Dv ESC
510character,
511.Sy \&^X
512maps to a control-X for any appropriate X,
513and the sequences
514.Sy \&\en
515.Sy \&\er
516.Sy \&\et
517.Sy \&\eb
518.Sy \&\ef
519map to linefeed, return, tab, backspace, and formfeed, respectively.
520Finally, characters may be given as three octal digits after a
521.Sy \&\e ,
522and the characters
523.Sy \&^
524and
525.Sy \&\e
526may be given as
527.Sy \&\e^
528and
529.Sy \&\e\e .
530If it is necessary to place a
531.Sy \&:
532in a capability it must be escaped in
533octal as
534.Sy \&\e072 .
535If it is necessary to place a
536.Dv NUL
537character in a string capability it
538must be encoded as
539.Sy \&\e200 .
540(The routines that deal with
541.Nm
542use C strings and strip the high bits of the output very late, so that
543a
544.Sy \&\e200
545comes out as a
546.Sy \&\e000
547would.)
548.Pp
549Sometimes individual capabilities must be commented out.
550To do this, put a period before the capability name.
551For example, see the first
552.Sy \&cr
553and
554.Sy \&ta
555in the example above.
556.Ss Preparing Descriptions
557The most effective way to prepare a terminal description is by imitating
558the description of a similar terminal in
559.Nm
560and to build up a description gradually, using partial descriptions
561with
562.Xr \&vi
563to check that they are correct.
564Be aware that a very unusual terminal may expose deficiencies in
565the ability of the
566.Nm
567file to describe it
568or bugs in
569.Xr \&vi .
570To easily test a new terminal description you are working on
571you can put it in your home directory in a file called
572.Pa .termcap
573and programs will look there before looking in
574.Pa /usr/share/misc/termcap .
575You can also set the environment variable
576.Ev TERMPATH
577to a list of absolute file pathnames (separated by spaces or colons),
578one of which contains the description you are working on,
579and programs will search them in the order listed, and nowhere else.
580See
581.Xr termcap 3 .
582The
583.Ev TERMCAP
584environment variable is usually set to the
585.Nm
586entry itself
587to avoid reading files when starting up a program.
588.Pp
589To get the padding for insert-line right
590(if the terminal manufacturer did not document it),
591a severe test is to use
592.Xr \&vi
593to edit
594.Pa /etc/passwd
595at 9600 baud, delete roughly 16 lines from the middle of the screen,
596then hit the `u' key several times quickly.
597If the display messes up, more padding is usually needed.
598A similar test can be used for insert-character.
599.Ss Basic Capabilities
600The number of columns on each line of the display is given by the
601.Sy \&co
602numeric capability.
603If the display is a
604.Tn CRT ,
605then the
606number of lines on the screen is given by the
607.Sy \&li
608capability.
609If the display wraps around to the beginning of the next line when
610the cursor reaches the right margin, then it should have the
611.Sy \&am
612capability.
613If the terminal can clear its screen,
614the code to do this is given by the
615.Sy \&cl
616string capability.
617If the terminal overstrikes
618(rather than clearing the position when a character is overwritten),
619it should have the
620.Sy \&os
621capability.
622If the terminal is a printing terminal,
623with no soft copy unit,
624give it both
625.Sy \&hc
626and
627.Sy \&os .
628.Pf ( Sy \&os
629applies to storage scope terminals,
630such as the Tektronix 4010 series,
631as well as to hard copy and
632.Tn APL
633terminals.)
634If there is a code to move the cursor to the left edge of the current row,
635give this as
636.Sy \&cr .
637(Normally this will be carriage-return,
638.Sy \&^M . )
639If there is a code to produce an audible signal (bell, beep,
640etc. ) ,
641give this as
642.Sy \&bl .
643.Pp
644If there is a code (such as backspace)
645to move the cursor one position to the left,
646that capability should be given as
647.Sy \&le .
648Similarly,
649codes to move to the right, up, and down
650should be given as
651.Sy \&nd ,
652.Sy \&up ,
653and
654.Sy \&do ,
655respectively.
656These
657.Em local cursor motions
658should not alter the text they pass over;
659for example, you would not normally use
660.Dq nd=\ \&
661unless the terminal has the
662.Sy \&os
663capability,
664because the space would erase the character moved over.
665.Pp
666A very important point here is that the local cursor motions encoded
667in
668.Nm
669have undefined behavior at the left and top edges of a
670.Tn CRT
671display.
672Programs should never attempt to backspace around the left edge,
673unless
674.Sy \&bw
675is given, and never attempt to go up off the top
676using local cursor motions.
677.Pp
678In order to scroll text up,
679a program goes to the bottom left corner of the screen and sends the
680.Sy \&sf
681(index) string.
682To scroll text down,
683a program goes to the top left corner of the screen and sends the
684.Sy \&sr
685(reverse index) string.
686The strings
687.Sy \&sf
688and
689.Sy \&sr
690have undefined behavior
691when not on their respective corners of the screen.
692Parameterized versions of the scrolling sequences are
693.Sy \&SF
694and
695.Sy \&SR ,
696which have the same semantics as
697.Sy \&sf
698and
699.Sy \&sr
700except that they take one parameter
701and scroll that many lines.
702They also have undefined behavior
703except at the appropriate corner of the screen.
704.Pp
705The
706.Sy \&am
707capability tells whether the cursor sticks at the right
708edge of the screen when text is output there,
709but this does not necessarily apply to
710.Sy \&nd
711from the last column.
712Leftward local motion is defined from the left edge only when
713.Sy \&bw
714is given; then an
715.Sy \&le
716from the left edge will move to the right edge of the previous row.
717This is useful for drawing a box around the edge of the screen,
718for example.
719If the terminal has switch-selectable automatic margins,
720the
721.Nm
722description usually assumes that this feature is on,
723.Em i.e . ,
724.Sy \&am .
725If the terminal has a command
726that moves to the first column of the next line,
727that command can be given as
728.Sy \&nw
729(newline).
730It is permissible for this to clear the remainder of the current line,
731so if the terminal has no correctly-working
732.Tn \&CR
733and
734.Tn \&LF
735it may still be possible to craft a working
736.Sy \&nw
737out of one or both of them.
738.Pp
739These capabilities suffice to describe hardcopy and
740.Dq glass-tty
741terminals.
742Thus the Teletype model 33 is described as
743.Bd -literal -offset indent
744T3\||\|tty33\||\|33\||\|tty\||\|Teletype model 33:\e
745	:bl=^G:co#72:cr=^M:do=^J:hc:os:
746.Ed
747.Pp
748and the Lear Siegler
749.Tn ADM Ns \-3
750is described as
751.Bd -literal -offset indent
752l3\||\|adm3\||\|3\||\|LSI \s-1ADM\s0-3:\e
753:am:bl=^G:cl=^Z:co#80:cr=^M:do=^J:le=^H:li#24:sf=^J:
754.Ed
755.Ss Parameterized Strings
756Cursor addressing and other strings requiring parameters
757are described by a
758parameterized string capability, with
759.Xr printf 3 Ns \-like
760escapes
761.Sy \&%x
762in it,
763while other characters are passed through unchanged.
764For example, to address the cursor the
765.Sy \&cm
766capability is given, using two parameters: the row and column to move to.
767(Rows and columns are numbered from zero and refer to the physical screen
768visible to the user, not to any unseen memory.
769If the terminal has memory-relative cursor addressing,
770that can be indicated by an analogous
771.Sy \&CM
772capability.)
773.Pp
774The
775.Sy \&%
776encodings have the following meanings:
777.Bl -column xxxxx
778.It "%%	output `%'"
779.It "%d	output value as in"
780.Xr printf
781%d
782.It "%2	output value as in"
783.Xr printf
784%2d
785.It "%3	output value as in"
786.Xr printf
787%3d
788.It "%.	output value as in"
789.Xr printf
790%c
791.It "%+" Ns Em x Ta No add
792.Em x
793to value, then do %.
794.It "%>" Ns Em \&xy Ta No if
795value >
796.Em x
797then add
798.Em y ,
799no output
800.It "%r	reverse order of two parameters, no output"
801.It "%i	increment by one, no output"
802.It "%n	exclusive-or all parameters with 0140 (Datamedia 2500)"
803.It "%B" Ta Tn BCD No "(16*(value/10)) + (value%10), no output"
804.It "%D	Reverse coding (value \- 2*(value%16)), no output (Delta Data)."
805.El
806.Pp
807Consider the Hewlett-Packard 2645, which, to get to row 3 and column 12, needs
808to be sent
809.Dq \eE&a12c03Y
810padded for 6 milliseconds.
811Note that the order
812of the row and column coordinates is reversed here
813and that the row and column
814are sent as two-digit integers.
815Thus its
816.Sy \&cm
817capability is
818.Dq Li cm=6\eE&%r%2c%2Y .
819.Pp
820The Datamedia 2500 needs the current row and column sent
821encoded in binary using
822.Dq \&%. .
823Terminals that use
824.Dq \&%.
825need to be able to
826backspace the cursor
827.Po Sy \&le Pc
828and to move the cursor up one line on the screen
829.Po Sy \&up Pc .
830This is necessary because it is not always safe to transmit
831.Sy \&\en ,
832.Sy \&^D ,
833and
834.Sy \&\er ,
835as the system may change or discard them.
836(Programs using
837.Nm
838must set terminal modes so that tabs are not expanded, so
839.Sy \&\et
840is safe to send.
841This turns out to be essential for the Ann Arbor 4080.)
842.Pp
843A final example is the Lear Siegler
844.Tn ADM Ns \-3a,
845which offsets row and column
846by a blank character, thus
847.Dq Li cm=\eE=%+ %+\ \& .
848.Pp
849Row or column absolute cursor addressing
850can be given as single parameter capabilities
851.Sy \&ch
852(horizontal position absolute) and
853.Sy \&cv
854(vertical position absolute).
855Sometimes these are shorter than the more general two-parameter sequence
856(as with the Hewlett-Packard 2645) and can be used in preference to
857.Sy \&cm .
858If there are parameterized local motions
859.Pf ( Em e.g . ,
860move
861.Ar n
862positions to the right)
863these can be given as
864.Sy \&DO ,
865.Sy \&LE ,
866.Sy \&RI ,
867and
868.Sy \&UP
869with a single parameter indicating how many positions to move.
870These are primarily useful if the terminal does not have
871.Sy \&cm ,
872such as the Tektronix 4025.
873.Ss Cursor Motions
874.Pp
875If the terminal has a fast way to home the cursor
876(to the very upper left corner of the screen), this can be given as
877.Sy \&ho .
878Similarly, a fast way of getting to the lower left-hand corner
879can be given as
880.Sy \&ll ;
881this may involve going up with
882.Sy \&up
883from the home position,
884but a program should never do this itself (unless
885.Sy \&ll
886does), because it can
887make no assumption about the effect of moving up from the home position.
888Note that the home position is the same as
889cursor address (0,0): to the top left corner of the screen, not of memory.
890(Therefore, the
891.Dq \eEH
892sequence on Hewlett-Packard terminals
893cannot be used for
894.Sy \&ho . )
895.Ss Area Clears
896If the terminal can clear from the current position to the end of the
897line, leaving the cursor where it is, this should be given as
898.Sy \&ce .
899If the terminal can clear from the current position to the end of the
900display, this should be given as
901.Sy \&cd .
902.Sy \&cd
903must only be invoked from the first column of a line.
904(Therefore,
905it can be simulated by a request to delete a large number of lines,
906if a true
907.Sy \&cd
908is not available.)
909.Ss Insert/Delete Line
910If the terminal can open a new blank line
911before the line containing the cursor,
912this should be given as
913.Sy \&al ;
914this must be invoked only from the first
915position of a line.
916The cursor must then appear at the left of the newly blank line.
917If the terminal can delete the line that the cursor is on, this
918should be given as
919.Sy \&dl ;
920this must only be used from the first position on
921the line to be deleted.
922Versions of
923.Sy \&al
924and
925.Sy \&dl
926which take a single parameter
927and insert or delete that many lines
928can be given as
929.Sy \&AL
930and
931.Sy \&DL .
932If the terminal has a settable scrolling region
933(like the VT100),
934the command to set this can be described with the
935.Sy \&cs
936capability,
937which takes two parameters: the top and bottom lines of the scrolling region.
938The cursor position is, alas, undefined after using this command.
939It is possible to get the effect of insert or delete line
940using this command \(em the
941.Sy \&sc
942and
943.Sy \&rc
944(save and restore cursor) commands are also useful.
945Inserting lines at the top or bottom of the screen can also be done using
946.Sy \&sr
947or
948.Sy \&sf
949on many terminals without a true insert/delete line,
950and is often faster even on terminals with those features.
951.Pp
952If the terminal has the ability to define a window as part of memory
953which all commands affect, it should be given as the parameterized string
954.Sy \&wi .
955The four parameters are the starting and ending lines in memory
956and the starting and ending columns in memory, in that order.
957(This
958.Xr terminfo
959capability is described for completeness.
960It is unlikely that any
961.Nm Ns \- Ns using
962program will support it.)
963.Pp
964If the terminal can retain display memory above the screen, then the
965.Sy \&da
966capability should be given;
967if display memory can be retained
968below, then
969.Sy \&db
970should be given.
971These indicate
972that deleting a line or scrolling may bring non-blank lines up from below
973or that scrolling back with
974.Sy \&sr
975may bring down non-blank lines.
976.Ss Insert/Delete Character
977There are two basic kinds of intelligent terminals with respect to
978insert/delete character that can be described using
979.Nm Ns .
980The most common insert/delete character operations affect only the characters
981on the current line and shift characters off the end of the line rigidly.
982Other terminals, such as the Concept\-100 and the Perkin Elmer Owl, make
983a distinction between typed and untyped blanks on the screen, shifting
984upon an insert or delete only to an untyped blank on the screen which is
985either eliminated or expanded to two untyped blanks.
986You can determine
987the kind of terminal you have by clearing the screen then typing
988text separated by cursor motions.
989Type
990.Dq Li abc\ \ \ \ def
991using local
992cursor motions (not spaces) between the
993.Dq abc
994and the
995.Dq def .
996Then position the cursor before the
997.Dq abc
998and put the terminal in insert
999mode.
1000If typing characters causes the rest of the line to shift
1001rigidly and characters to fall off the end, then your terminal does
1002not distinguish between blanks and untyped positions.
1003If the
1004.Dq abc
1005shifts over to the
1006.Dq def
1007which then move together around the end of the
1008current line and onto the next as you insert, then you have the second type of
1009terminal and should give the capability
1010.Sy \&in ,
1011which stands for
1012.Dq insert null .
1013While these are two logically separate attributes
1014(one line
1015.Em \&vs .
1016multi-line insert mode,
1017and special treatment of untyped spaces),
1018we have seen no terminals whose insert
1019mode cannot be described with the single attribute.
1020.Pp
1021The
1022.Nm
1023entries can describe both terminals that have an insert mode and terminals
1024that send a simple sequence to open a blank position on the current line.
1025Give as
1026.Sy \&im
1027the sequence to get into insert mode.
1028Give as
1029.Sy \&ei
1030the sequence to leave insert mode.
1031Now give as
1032.Sy \&ic
1033any sequence that needs to be sent just before
1034each character to be inserted.
1035Most terminals with a true insert mode
1036will not give
1037.Sy \&ic ;
1038terminals that use a sequence to open a screen
1039position should give it here.
1040(If your terminal has both,
1041insert mode is usually preferable to
1042.Sy \&ic .
1043Do not give both unless the terminal actually requires both to be used
1044in combination.)
1045If post-insert padding is needed, give this as a number of milliseconds
1046in
1047.Sy \&ip
1048(a string option).
1049Any other sequence that may need to be
1050sent after insertion of a single character can also be given in
1051.Sy \&ip .
1052If your terminal needs to be placed into an `insert mode'
1053and needs a special code preceding each inserted character,
1054then both
1055.Sy \&im Ns / Sy \&ei
1056and
1057.Sy \&ic
1058can be given, and both will be used.
1059The
1060.Sy \&IC
1061capability, with one parameter
1062.Em n ,
1063will repeat the effects of
1064.Sy \&ic
1065.Em n
1066times.
1067.Pp
1068It is occasionally necessary to move around while in insert mode
1069to delete characters on the same line
1070.Pf ( Em e.g . ,
1071if there is a tab after
1072the insertion position).
1073If your terminal allows motion while in
1074insert mode, you can give the capability
1075.Sy \&mi
1076to speed up inserting
1077in this case.
1078Omitting
1079.Sy \&mi
1080will affect only speed.
1081Some terminals
1082(notably Datamedia's) must not have
1083.Sy \&mi
1084because of the way their
1085insert mode works.
1086.Pp
1087Finally, you can specify
1088.Sy \&dc
1089to delete a single character,
1090.Sy \&DC
1091with one parameter
1092.Em n
1093to delete
1094.Em n
1095characters,
1096and delete mode by giving
1097.Sy \&dm
1098and
1099.Sy \&ed
1100to enter and exit delete mode
1101(which is any mode the terminal needs to be placed in for
1102.Sy \&dc
1103to work).
1104.Ss Highlighting, Underlining, and Visible  Bells
1105If your terminal has one or more kinds of display attributes,
1106these can be represented in a number of different ways.
1107You should choose one display form as
1108.Em standout mode ,
1109representing a good high-contrast, easy-on-the-eyes format
1110for highlighting error messages and other attention getters.
1111(If you have a choice, reverse video plus half-bright is good,
1112or reverse video alone.)
1113The sequences to enter and exit standout mode
1114are given as
1115.Sy \&so
1116and
1117.Sy \&se ,
1118respectively.
1119If the code to change into or out of standout
1120mode leaves one or even two blank spaces or garbage characters on the screen,
1121as the
1122.Tn TVI
1123912 and Teleray 1061 do,
1124then
1125.Sy \&sg
1126should be given to tell how many characters are left.
1127.Pp
1128Codes to begin underlining and end underlining can be given as
1129.Sy \&us
1130and
1131.Sy \&ue ,
1132respectively.
1133Underline mode change garbage is specified by
1134.Sy \&ug ,
1135similar to
1136.Sy \&sg .
1137If the terminal has a code to underline the current character and move
1138the cursor one position to the right,
1139such as the Microterm Mime,
1140this can be given as
1141.Sy \&uc .
1142.Pp
1143Other capabilities to enter various highlighting modes include
1144.Sy \&mb
1145(blinking),
1146.Sy \&md
1147(bold or extra bright),
1148.Sy \&mh
1149(dim or half-bright),
1150.Sy \&mk
1151(blanking or invisible text),
1152.Sy \&mp
1153(protected),
1154.Sy \&mr
1155(reverse video),
1156.Sy \&me
1157(turn off
1158.Em all
1159attribute modes),
1160.Sy \&as
1161(enter alternate character set mode), and
1162.Sy \&ae
1163(exit alternate character set mode).
1164Turning on any of these modes singly may or may not turn off other modes.
1165.Pp
1166If there is a sequence to set arbitrary combinations of mode,
1167this should be given as
1168.Sy \&sa
1169(set attributes), taking 9 parameters.
1170Each parameter is either 0 or 1,
1171as the corresponding attributes is on or off.
1172The 9 parameters are, in order: standout, underline, reverse, blink,
1173dim, bold, blank, protect, and alternate character set.
1174Not all modes need be supported by
1175.Sy \&sa ,
1176only those for which corresponding attribute commands exist.
1177(It is unlikely that a
1178.Nm Ns \-using
1179program will support this capability, which is defined for compatibility
1180with
1181.Xr terminfo . )
1182.Pp
1183Terminals with the
1184.Dq magic cookie
1185glitches
1186.Pf ( Sy \&sg
1187and
1188.Sy \&ug ) ,
1189rather than maintaining extra attribute bits for each character cell,
1190instead deposit special
1191.Dq cookies ,
1192or
1193.Dq garbage characters ,,
1194when they receive mode-setting sequences,
1195which affect the display algorithm.
1196.Pp
1197Some terminals,
1198such as the Hewlett-Packard 2621,
1199automatically leave standout
1200mode when they move to a new line or when the cursor is addressed.
1201Programs using standout mode
1202should exit standout mode on such terminals
1203before moving the cursor or sending a newline.
1204On terminals where this is not a problem,
1205the
1206.Sy \&ms
1207capability should be present
1208to say that this overhead is unnecessary.
1209.Pp
1210If the terminal has
1211a way of flashing the screen to indicate an error quietly
1212(a bell replacement),
1213this can be given as
1214.Sy \&vb ;
1215it must not move the cursor.
1216.Pp
1217If the cursor needs to be made more visible than normal
1218when it is not on the bottom line
1219(to change, for example, a non-blinking underline into an easier-to-find
1220block or blinking underline),
1221give this sequence as
1222.Sy \&vs .
1223If there is a way to make the cursor completely invisible, give that as
1224.Sy \&vi .
1225The capability
1226.Sy \&ve ,
1227which undoes the effects of both of these modes,
1228should also be given.
1229.Pp
1230If your terminal correctly displays underlined characters
1231(with no special codes needed)
1232even though it does not overstrike,
1233then you should give the capability
1234.Sy \&ul .
1235If overstrikes are erasable with a blank,
1236this should be indicated by giving
1237.Sy \&eo .
1238.Ss Keypad
1239If the terminal has a keypad that transmits codes when the keys are pressed,
1240this information can be given.
1241Note that it is not possible to handle
1242terminals where the keypad only works in local mode
1243(this applies, for example, to the unshifted Hewlett-Packard 2621 keys).
1244If the keypad can be set to transmit or not transmit,
1245give these codes as
1246.Sy \&ks
1247and
1248.Sy \&ke .
1249Otherwise the keypad is assumed to always transmit.
1250The codes sent by the left-arrow, right-arrow, up-arrow, down-arrow,
1251and home keys can be given as
1252.Sy \&kl ,
1253.Sy \&kr ,
1254.Sy \&ku ,
1255.Sy \&kd ,
1256and
1257.Sy \&kh ,
1258respectively.
1259If there are function keys such as f0, f1, ..., f9, the codes they send
1260can be given as
1261.Sy \&k0 ,
1262.Sy \&k1 ,
1263...,
1264.Sy \&k9 .
1265If these keys have labels other than the default f0 through f9, the labels
1266can be given as
1267.Sy \&l0 ,
1268.Sy \&l1 ,
1269...,
1270.Sy \&l9 .
1271The codes transmitted by certain other special keys can be given:
1272.Sy \&kH
1273(home down),
1274.Sy \&kb
1275(backspace),
1276.Sy \&ka
1277(clear all tabs),
1278.Sy \&kt
1279(clear the tab stop in this column),
1280.Sy \&kC
1281(clear screen or erase),
1282.Sy \&kD
1283(delete character),
1284.Sy \&kL
1285(delete line),
1286.Sy \&kM
1287(exit insert mode),
1288.Sy \&kE
1289(clear to end of line),
1290.Sy \&kS
1291(clear to end of screen),
1292.Sy \&kI
1293(insert character or enter insert mode),
1294.Sy \&kA
1295(insert line),
1296.Sy \&kN
1297(next page),
1298.Sy \&kP
1299(previous page),
1300.Sy \&kF
1301(scroll forward/down),
1302.Sy \&kR
1303(scroll backward/up), and
1304.Sy \&kT
1305(set a tab stop in this column).
1306In addition, if the keypad has a 3 by 3 array of keys
1307including the four arrow keys, then the other five keys can be given as
1308.Sy \&K1 ,
1309.Sy \&K2 ,
1310.Sy \&K3 ,
1311.Sy \&K4 ,
1312and
1313.Sy \&K5 .
1314These keys are useful when the effects of a 3 by 3 directional pad are needed.
1315The obsolete
1316.Sy \&ko
1317capability formerly used to describe
1318.Dq other
1319function keys has been
1320completely supplanted by the above capabilities.
1321.Pp
1322The
1323.Sy \&ma
1324entry is also used to indicate arrow keys on terminals that have
1325single-character arrow keys.
1326It is obsolete but still in use in
1327version 2 of
1328.Sy \&vi
1329which must be run on some minicomputers due to
1330memory limitations.
1331This field is redundant with
1332.Sy \&kl ,
1333.Sy \&kr ,
1334.Sy \&ku ,
1335.Sy \&kd ,
1336and
1337.Sy \&kh .
1338It consists of groups of two characters.
1339In each group, the first character is what an arrow key sends, and the
1340second character is the corresponding
1341.Sy \&vi
1342command.
1343These commands are
1344.Ar h
1345for
1346.Sy \&kl ,
1347.Ar j
1348for
1349.Sy \&kd ,
1350.Ar k
1351for
1352.Sy \&ku ,
1353.Ar l
1354for
1355.Sy \&kr ,
1356and
1357.Ar H
1358for
1359.Sy \&kh .
1360For example, the Mime would have
1361.Dq Li ma=^Hh^Kj^Zk^Xl
1362indicating arrow keys left (^H), down (^K), up (^Z), and right (^X).
1363(There is no home key on the Mime.)
1364.Ss Tabs and Initialization
1365If the terminal needs to be in a special mode when running
1366a program that uses these capabilities,
1367the codes to enter and exit this mode can be given as
1368.Sy \&ti
1369and
1370.Sy \&te .
1371This arises, for example, from terminals like the Concept with more than
1372one page of memory.
1373If the terminal has only memory-relative cursor addressing and not
1374screen-relative cursor addressing,
1375a screen-sized window must be fixed into
1376the display for cursor addressing to work properly.
1377This is also used for the Tektronix 4025, where
1378.Sy \&ti
1379sets the command character to be the one used by
1380.Nm Ns .
1381.Pp
1382Other capabilities
1383include
1384.Sy \&is ,
1385an initialization string for the terminal,
1386and
1387.Sy \&if ,
1388the name of a file containing long initialization strings.
1389These strings are expected to set the terminal into modes
1390consistent with the rest of the
1391.Nm
1392description.
1393They are normally sent to the terminal by the
1394.Xr tset
1395program each time the user logs in.
1396They will be printed in the following order:
1397.Sy \&is ;
1398setting tabs using
1399.Sy \&ct
1400and
1401.Sy \&st ;
1402and finally
1403.Sy \&if .
1404.Pf ( Xr Terminfo
1405uses
1406.Sy \&i\&1-i2
1407instead of
1408.Sy \&is
1409and runs the program
1410.Sy \&iP
1411and prints
1412.Sy "\&i\&3"
1413after the other initializations.)
1414A pair of sequences that does a harder reset from a totally unknown state
1415can be analogously given as
1416.Sy \&rs
1417and
1418.Sy \&if .
1419These strings are output by the
1420.Xr reset
1421program, which is used when the terminal gets into a wedged state.
1422.Pf ( Xr Terminfo
1423uses
1424.Sy "\&r1-r3"
1425instead of
1426.Sy \&rs . )
1427Commands are normally placed in
1428.Sy \&rs
1429and
1430.Sy \&rf
1431only if they produce annoying effects on the screen and are not necessary
1432when logging in.
1433For example, the command to set the VT100 into 80-column mode
1434would normally be part of
1435.Sy \&is ,
1436but it causes an annoying glitch of the screen and is not normally needed
1437since the terminal is usually already in 80-column mode.
1438.Pp
1439If the terminal has hardware tabs,
1440the command to advance to the next tab stop can be given as
1441.Sy \&ta
1442(usually
1443.Sy \&^I ) .
1444A
1445.Dq backtab
1446command which moves leftward to the previous tab stop
1447can be given as
1448.Sy \&bt .
1449By convention,
1450if the terminal driver modes indicate that tab stops are being expanded
1451by the computer rather than being sent to the terminal,
1452programs should not use
1453.Sy \&ta
1454or
1455.Sy \&bt
1456even if they are present,
1457since the user may not have the tab stops properly set.
1458If the terminal has hardware tabs that are initially set every
1459.Ar n
1460positions when the terminal is powered up, then the numeric parameter
1461.Sy \&it
1462is given, showing the number of positions between tab stops.
1463This is normally used by the
1464.Xr tset
1465command to determine whether to set the driver mode for hardware tab
1466expansion, and whether to set the tab stops.
1467If the terminal has tab stops that can be saved in nonvolatile memory, the
1468.Nm
1469description can assume that they are properly set.
1470.Pp
1471If there are commands to set and clear tab stops, they can be given as
1472.Sy \&ct
1473(clear all tab stops) and
1474.Sy \&st
1475(set a tab stop in the current column of every row).
1476If a more complex sequence is needed to set the tabs than can be
1477described by this, the sequence can be placed in
1478.Sy \&is
1479or
1480.Sy \&if .
1481.Ss Delays
1482Certain capabilities control padding in the terminal driver.
1483These are primarily needed by hardcopy terminals and are used by the
1484.Xr tset
1485program to set terminal driver modes appropriately.
1486Delays embedded in the capabilities
1487.Sy \&cr ,
1488.Sy \&sf ,
1489.Sy \&le ,
1490.Sy \&ff ,
1491and
1492.Sy \&ta
1493will cause the appropriate delay bits to be set in the terminal driver.
1494If
1495.Sy \&pb
1496(padding baud rate) is given, these values can be ignored at baud rates
1497below the value of
1498.Sy \&pb .
1499For
1500.Bx 4.2
1501.Xr tset ,
1502the delays are given as numeric capabilities
1503.Sy \&dC ,
1504.Sy \&dN ,
1505.Sy \&dB ,
1506.Sy \&dF ,
1507and
1508.Sy \&dT
1509instead.
1510.Ss Miscellaneous
1511If the terminal requires other than a
1512.Dv NUL
1513(zero) character as a pad,
1514this can be given as
1515.Sy \&pc .
1516Only the first character of the
1517.Sy \&pc
1518string is used.
1519.Pp
1520If the terminal has commands to save and restore the position of the
1521cursor, give them as
1522.Sy \&sc
1523and
1524.Sy \&rc .
1525.Pp
1526If the terminal has an extra
1527.Dq status line
1528that is not normally used by
1529software, this fact can be indicated.
1530If the status line is viewed as an extra line below the bottom line,
1531then the capability
1532.Sy \&hs
1533should be given.
1534Special strings to go to a position in the status line and to return
1535from the status line can be given as
1536.Sy \&ts
1537and
1538.Sy \&fs .
1539.Pf ( Xr \&fs
1540must leave the cursor position in the same place that it was before
1541.Sy \&ts .
1542If necessary, the
1543.Sy \&sc
1544and
1545.Sy \&rc
1546strings can be included in
1547.Sy \&ts
1548and
1549.Sy \&fs
1550to get this effect.)
1551The capability
1552.Sy \&ts
1553takes one parameter, which is the column number of the status line
1554to which the cursor is to be moved.
1555If escape sequences and other special commands such as tab work while in
1556the status line, the flag
1557.Sy \&es
1558can be given.
1559A string that turns off the status line (or otherwise erases its contents)
1560should be given as
1561.Sy \&ds .
1562The status line is normally assumed to be the same width as the
1563rest of the screen,
1564.Em i.e . ,
1565.Sy \&co .
1566If the status line is a different width (possibly because the terminal
1567does not allow an entire line to be loaded), then its width in columns
1568can be indicated with the numeric parameter
1569.Sy \&ws .
1570.Pp
1571If the terminal can move up or down half a line, this can be
1572indicated with
1573.Sy \&hu
1574(half-line up) and
1575.Sy \&hd
1576(half-line down).
1577This is primarily useful for superscripts and subscripts on hardcopy
1578terminals.
1579If a hardcopy terminal can eject to the next page (form feed),
1580give this as
1581.Sy \&ff
1582(usually
1583.Sy \&^L ) .
1584.Pp
1585If there is a command to repeat a given character a given number of times
1586(to save time transmitting a large number of identical characters),
1587this can be indicated with the parameterized string
1588.Sy \&rp .
1589The first parameter is the character to be repeated and the second is
1590the number of times to repeat it.
1591(This is a
1592.Xr terminfo
1593feature that is unlikely to be supported by a program that uses
1594.Nm Ns . )
1595.Pp
1596If the terminal has a settable command character, such as the
1597Tektronix 4025, this can be indicated with
1598.Sy \&CC .
1599A prototype command character is chosen which is used in all capabilities.
1600This character is given in the
1601.Sy \&CC
1602capability to identify it.
1603The following convention is supported on some
1604.Ux
1605systems:
1606The environment is to be searched for a
1607.Ev \&CC
1608variable,
1609and if found,
1610all occurrences of the prototype character are replaced by the character
1611in the environment variable.
1612This use of the
1613.Ev \&CC
1614environment variable
1615is a very bad idea, as it conflicts with
1616.Xr make 1 .
1617.Pp
1618Terminal descriptions that do not represent a specific kind of known
1619terminal, such as
1620.Em switch ,
1621.Em dialup ,
1622.Em patch ,
1623and
1624.Xr network ,
1625should include the
1626.Sy \&gn
1627(generic) capability so that programs can complain that they do not know
1628how to talk to the terminal.
1629(This capability does not apply to
1630.Em virtual
1631terminal descriptions for which the escape sequences are known.)
1632.Pp
1633If the terminal uses xoff/xon
1634.Pq Tn DC3 Ns / Ns Tn DC1
1635handshaking for flow control, give
1636.Sy \&xo .
1637Padding information should still be included so that routines can make
1638better decisions about costs, but actual pad characters will not be
1639transmitted.
1640.Pp
1641If the terminal has a
1642.Dq meta key
1643which acts as a shift key, setting the
16448th bit of any character transmitted, then this fact can be indicated with
1645.Sy \&km .
1646Otherwise, software will assume that the 8th bit is parity and it will
1647usually be cleared.
1648If strings exist to turn this
1649.Dq meta mode
1650on and off, they can be given as
1651.Sy \&mm
1652and
1653.Sy \&mo .
1654.Pp
1655If the terminal has more lines of memory than will fit on the screen at once,
1656the number of lines of memory can be indicated with
1657.Sy \&lm .
1658An explicit value of 0 indicates that the number of lines is not fixed,
1659but that there is still more memory than fits on the screen.
1660.Pp
1661If the terminal is one of those supported by the
1662.Ux
1663system virtual
1664terminal protocol, the terminal number can be given as
1665.Sy \&vt .
1666.Pp
1667Media copy strings which control an auxiliary printer
1668connected to the terminal can be given as
1669.Sy \&ps :
1670print the contents of the screen;
1671.Sy \&pf :
1672turn off the printer; and
1673.Sy \&po :
1674turn on the printer.
1675When the printer is on, all text sent to the terminal will be sent to the
1676printer.
1677It is undefined whether the text is also displayed on the terminal screen
1678when the printer is on.
1679A variation
1680.Sy \&pO
1681takes one parameter and leaves the printer on for as many characters as the
1682value of the parameter, then turns the printer off.
1683The parameter should not exceed 255.
1684All text, including
1685.Sy \&pf ,
1686is transparently passed to the printer while
1687.Sy \&pO
1688is in effect.
1689.Pp
1690Strings to program function keys can be given as
1691.Sy \&pk ,
1692.Sy \&pl ,
1693and
1694.Sy \&px .
1695Each of these strings takes two parameters: the function key number
1696to program (from 0 to 9) and the string to program it with.
1697Function key numbers out of this range may program undefined keys
1698in a terminal-dependent manner.
1699The differences among the capabilities are that
1700.Sy \&pk
1701causes pressing the given key to be the same as the user typing the given
1702string;
1703.Sy \&pl
1704causes the string to be executed by the terminal in local mode;
1705and
1706.Sy \&px
1707causes the string to be transmitted to the computer.
1708Unfortunately, due to lack of a definition for string parameters in
1709.Nm ,
1710only
1711.Xr terminfo
1712supports these capabilities.
1713.Ss Glitches and Braindamage
1714Hazeltine terminals, which do not allow `~' characters to be displayed,
1715should indicate
1716.Sy \&hz .
1717.Pp
1718The
1719.Sy \&nc
1720capability, now obsolete, formerly indicated Datamedia terminals,
1721which echo
1722.Sy \&\er \en
1723for
1724carriage return then ignore a following linefeed.
1725.Pp
1726Terminals that ignore a linefeed immediately after an
1727.Sy \&am
1728wrap, such as the Concept, should indicate
1729.Sy \&xn .
1730.Pp
1731If
1732.Sy \&ce
1733is required to get rid of standout
1734(instead of merely writing normal text on top of it),
1735.Sy \&xs
1736should be given.
1737.Pp
1738Teleray terminals, where tabs turn all characters moved over to blanks,
1739should indicate
1740.Sy \&xt
1741(destructive tabs).
1742This glitch is also taken to mean that it is not possible
1743to position the cursor on top of a \*(lqmagic cookie\*(rq, and that
1744to erase standout mode it is necessary to use delete and insert line.
1745.Pp
1746The Beehive Superbee, which is unable to correctly transmit the
1747.Dv ESC
1748or
1749.Sy \&^C
1750characters, has
1751.Sy \&xb ,
1752indicating that the
1753.Dq \&f\&1
1754key is used for
1755.Dv ESC
1756and
1757.Dq \&f\&2
1758for ^C.
1759(Only certain Superbees have this problem, depending on the
1760.Tn ROM . )
1761.Pp
1762Other specific terminal problems may be corrected by adding more
1763capabilities of the form
1764.Sy x Em x .
1765.Ss Similar Terminals
1766If there are two very similar terminals,
1767one can be defined as being just like the other with certain exceptions.
1768The string capability
1769.Sy \&tc
1770can be given
1771with the name of the similar terminal.
1772This capability must be
1773.Em last ,
1774and the combined length of the entries
1775must not exceed 1024.
1776The capabilities given before
1777.Sy \&tc
1778override those in the terminal type invoked by
1779.Sy \&tc .
1780A capability can be canceled by placing
1781.Sy \&xx@
1782to the left of the
1783.Sy \&tc
1784invocation, where
1785.Sy \&xx
1786is the capability.
1787For example, the entry
1788.Bd -literal -offset indent
1789hn\||\|2621\-nl:ks@:ke@:tc=2621:
1790.Ed
1791.Pp
1792defines a
1793.Dq 2621\-nl
1794that does not have the
1795.Sy \&ks
1796or
1797.Sy \&ke
1798capabilities,
1799hence does not turn on the function key labels when in visual mode.
1800This is useful for different modes for a terminal, or for different
1801user preferences.
1802.Sh FILES
1803.Bl -tag -width /usr/share/misc/termcap.db -compact
1804.It Pa /usr/share/misc/termcap
1805File containing terminal descriptions.
1806.It Pa /usr/share/misc/termcap.db
1807Hash database file containing terminal descriptions (see
1808.Xr cap_mkdb 1 ) .
1809.It Pa /usr/src/share/termcap/terminfo_extensions.doc
1810A more complete list of entries for both termcap and terminfo.
1811.El
1812.Sh SEE ALSO
1813.Xr cap_mkdb 1 ,
1814.Xr ex 1 ,
1815.Xr more 1 ,
1816.Xr tset 1 ,
1817.Xr ul 1 ,
1818.Xr vi 1 ,
1819.Xr curses 3 ,
1820.Xr printf 3 ,
1821.Xr termcap 3 ,
1822.Xr term 5
1823.Sh CAVEATS AND BUGS
1824The
1825.Em Note :
1826.Nm
1827functions
1828were replaced by
1829.Xr terminfo
1830in
1831.At V
1832Release 2.0.
1833The transition will be relatively painless if capabilities flagged as
1834.Dq obsolete
1835are avoided.
1836.Pp
1837Lines and columns are now stored by the kernel as well as in the termcap
1838entry.
1839Most programs now use the kernel information primarily; the information
1840in this file is used only if the kernel does not have any information.
1841.Pp
1842The
1843.Xr \&vi 1
1844program allows only 256 characters for string capabilities, and the routines
1845in
1846.Xr termlib 3
1847do not check for overflow of this buffer.
1848The total length of a single entry (excluding only escaped newlines)
1849may not exceed 1024.
1850.Pp
1851Not all programs support all entries.
1852.Sh HISTORY
1853The
1854.Nm
1855file format appeared in
1856.Bx 3 .
1857