1TERMCAP(5) File Formats Manual TERMCAP(5)
2
6 termcap - terminal capability data base
7
9 /etc/termcap
10
12 Termcap is a data base describing terminals, used, e.g., by vi(1) and
13 curses(3X). Terminals are described in termcap by giving a set of
14 capabilities that they have and by describing how operations are per‐
15 formed. Padding requirements and initialization sequences are included
16 in termcap.
17 Entries in termcap consist of a number of `:'-separated fields. The
19 first entry for each terminal gives the names that are known for the
20 terminal, separated by `|' characters. The first name is always two
21 characters long and is used by older systems which store the terminal
22 type in a 16-bit word in a system-wide data base. The second name
23 given is the most common abbreviation for the terminal, the last name
24 given should be a long name fully identifying the terminal, and all
25 others are understood as synonyms for the terminal name. All names but
26 the first and last should be in lower case and contain no blanks; the
27 last name may well contain upper case and blanks for readability.
28 Terminal names (except for the last, verbose entry) should be chosen
30 using the following conventions. The particular piece of hardware mak‐
31 ing up the terminal should have a root name chosen, thus “hp2621”.
32 This name should not contain hyphens. Modes that the hardware can be
33 in or user preferences should be indicated by appending a hyphen and an
34 indicator of the mode. Therefore, a “vt100” in 132-column mode would
35 be “vt100-w”. The following suffixes should be used where possible:
36 Suffix Meaning Example
38 -w Wide mode (more than 80 columns) vt100-w
39 -am With automatic margins (usually default) vt100-am
40 -nam Without automatic margins vt100-nam
41 -n Number of lines on the screen aaa-60
42 -na No arrow keys (leave them in local) concept100-na
43 -np Number of pages of memory concept100-4p
44 -rv Reverse video concept100-rv
45
47 The characters in the Notes field in the table have the following mean‐
48 ings (more than one may apply to a capability):
49 N indicates numeric parameter(s)
51 P indicates that padding may be specified
52 ∗ indicates that padding may be based on the number of lines affected
53 o indicates capability is obsolete
54 “Obsolete” capabilities have no terminfo equivalents, since they were
56 considered useless, or are subsumed by other capabilities. New soft‐
57 ware should not rely on them at all.
58 Name Type Notes Description
60 ae str (P) End alternate character set
61 AL str (NP∗) Add n new blank lines
62 al str (P∗) Add new blank line
63 am bool Terminal has automatic margins
64 as str (P) Start alternate character set
65 bc str (o) Backspace if not ^H
66 bl str (P) Audible signal (bell)
67 bs bool (o) Terminal can backspace with ^H
68 bt str (P) Back tab
69 bw bool le (backspace) wraps from column 0 to last column
70 CC str Terminal settable command character in prototype
71 cd str (P∗) Clear to end of display
72 ce str (P) Clear to end of line
73 ch str (NP) Set cursor column (horizontal position)
74 cl str (P∗) Clear screen and home cursor
75 CM str (NP) Memory-relative cursor addressing
76 cm str (NP) Screen-relative cursor motion
77 co num Number of columns in a line (See BUGS section below)
78 cr str (P) Carriage return
79 cs str (NP) Change scrolling region (VT100)
80 ct str (P) Clear all tab stops
81 cv str (NP) Set cursor row (vertical position)
82 da bool Display may be retained above the screen
83 dB num (o) Milliseconds of bs delay needed (default 0)
84 db bool Display may be retained below the screen
85 DC str (NP∗) Delete n characters
86 dC num (o) Milliseconds of cr delay needed (default 0)
87 dc str (P∗) Delete character
88 dF num (o) Milliseconds of ff delay needed (default 0)
89 DL str (NP∗) Delete n lines
90 dl str (P∗) Delete line
91 dm str Enter delete mode
92 dN num (o) Milliseconds of nl delay needed (default 0)
93 DO str (NP∗) Move cursor down n lines
94 do str Down one line
95 ds str Disable status line
96 dT num (o) Milliseconds of horizontal tab delay needed (default 0)
97 dV num (o) Milliseconds of vertical tab delay needed (default 0)
98 ec str (NP) Erase n characters
99 ed str End delete mode
100 ei str End insert mode
101 eo bool Can erase overstrikes with a blank
102 EP bool (o) Even parity
103 es bool Escape can be used on the status line
104 ff str (P∗) Hardcopy terminal page eject
105 fs str Return from status line
106 gn bool Generic line type (e.g. dialup, switch)
107 hc bool Hardcopy terminal
108 HD bool (o) Half-duplex
109 hd str Half-line down (forward 1/2 linefeed)
110 ho str (P) Home cursor
111 hs bool Has extra “status line”
112 hu str Half-line up (reverse 1/2 linefeed)
113 hz bool Cannot print ~s (Hazeltine)
114 i1-i3 str Terminal initialization strings (terminfo only)
115 IC str (NP∗) Insert n blank characters
116 ic str (P∗) Insert character
117 if str Name of file containing initialization string
118 im str Enter insert mode
119 in bool Insert mode distinguishes nulls
120 iP str Pathname of program for initialization (terminfo only)
121 ip str (P∗) Insert pad after character inserted
122 is str Terminal initialization string (termcap only)
123 it num Tabs initially every n positions
124 K1 str Sent by keypad upper left
125 K2 str Sent by keypad upper right
126 K3 str Sent by keypad center
127 K4 str Sent by keypad lower left
128 K5 str Sent by keypad lower right
129 k0-k9 str Sent by function keys 0-9
130 kA str Sent by insert-line key
131 ka str Sent by clear-all-tabs key
132 kb str Sent by backspace key
133 kC str Sent by clear-screen or erase key
134 kD str Sent by delete-character key
135 kd str Sent by down-arrow key
136 kE str Sent by clear-to-end-of-line key
137 ke str Out of “keypad transmit” mode
138 kF str Sent by scroll-forward/down key
139 kH str Sent by home-down key
140 kh str Sent by home key
141 kI str Sent by insert-character or enter-insert-mode key
142 kL str Sent by delete-line key
143 kl str Sent by left-arrow key
144 kM str Sent by insert key while in insert mode
145 km bool Has a “meta” key (shift, sets parity bit)
146 kN str Sent by next-page key
147 kn num (o) Number of function (k0-k9) keys (default 0)
148 ko str (o) Termcap entries for other non-function keys
149 kP str Sent by previous-page key
150 kR str Sent by scroll-backward/up key
151 kr str Sent by right-arrow key
152 kS str Sent by clear-to-end-of-screen key
153 ks str Put terminal in “keypad transmit” mode
154 kT str Sent by set-tab key
155 kt str Sent by clear-tab key
156 ku str Sent by up-arrow key
157 l0-l9 str Labels on function keys if not “fn”
158 LC bool (o) Lower-case only
159 LE str (NP) Move cursor left n positions
160 le str (P) Move cursor left one position
161 li num Number of lines on screen or page (See BUGS section below)
162 ll str Last line, first column
163 lm num Lines of memory if > li (0 means varies)
164 ma str (o) Arrow key map (used by vi version 2 only)
165 mb str Turn on blinking attribute
166 md str Turn on bold (extra bright) attribute
167 me str Turn off all attributes
168 mh str Turn on half-bright attribute
169 mi bool Safe to move while in insert mode
170 mk str Turn on blank attribute (characters invisible)
171 ml str (o) Memory lock on above cursor
172 mm str Turn on “meta mode” (8th bit)
173 mo str Turn off “meta mode”
174 mp str Turn on protected attribute
175 mr str Turn on reverse-video attibute
176 ms bool Safe to move in standout modes
177 mu str (o) Memory unlock (turn off memory lock)
178 nc bool (o) No correctly-working cr (Datamedia 2500, Hazeltine 2000)
179 nd str Non-destructive space (cursor right)
180 NL bool (o) \n is newline, not line feed
181 nl str (o) Newline character if not \n
182 ns bool (o) Terminal is a CRT but doesn't scroll
183 nw str (P) Newline (behaves like cr followed by do)
184 OP bool (o) Odd parity
185 os bool Terminal overstrikes
186 pb num Lowest baud where delays are required
187 pc str Pad character (default NUL)
188 pf str Turn off the printer
189 pk str Program function key n to type string s (terminfo only)
190 pl str Program function key n to execute string s (terminfo only)
191 pO str (N) Turn on the printer for n bytes
192 po str Turn on the printer
193 ps str Print contents of the screen
194 pt bool (o) Has hardware tabs (may need to be set with is)
195 px str Program function key n to transmit string s (terminfo only)
196 r1-r3 str Reset terminal completely to sane modes (terminfo only)
197 rc str (P) Restore cursor to position of last sc
198 rf str Name of file containing reset codes
199 RI str (NP) Move cursor right n positions
200 rp str (NP∗) Repeat character c n times
201 rs str Reset terminal completely to sane modes (termcap only)
202 sa str (NP) Define the video attributes
203 sc str (P) Save cursor position
204 se str End standout mode
205 SF str (NP∗) Scroll forward n lines
206 sf str (P) Scroll text up
207 sg num Number of garbage chars left by so or se (default 0)
208 so str Begin standout mode
209 SR str (NP∗) Scroll backward n lines
210 sr str (P) Scroll text down
211 st str Set a tab in all rows, current column
212 ta str (P) Tab to next 8-position hardware tab stop
213 tc str Entry of similar terminal - must be last
214 te str String to end programs that use termcap
215 ti str String to begin programs that use termcap
216 ts str (N) Go to status line, column n
217 UC bool (o) Upper-case only
218 uc str Underscore one character and move past it
219 ue str End underscore mode
220 ug num Number of garbage chars left by us or ue (default 0)
221 ul bool Underline character overstrikes
222 UP str (NP∗) Move cursor up n lines
223 up str Upline (cursor up)
224 us str Start underscore mode
225 vb str Visible bell (must not move cursor)
226 ve str Make cursor appear normal (undo vs/vi)
227 vi str Make cursor invisible
228 vs str Make cursor very visible
229 vt num Virtual terminal number (not supported on all systems)
230 wi str (N) Set current window
231 ws num Number of columns in status line
232 xb bool Beehive (f1=ESC, f2=^C)
233 xn bool Newline ignored after 80 cols (Concept)
234 xo bool Terminal uses xoff/xon (DC3/DC1) handshaking
235 xr bool (o) Return acts like ce cr nl (Delta Data)
236 xs bool Standout not erased by overwriting (Hewlett-Packard)
237 xt bool Tabs ruin, magic so char (Teleray 1061)
238 xx bool (o) Tektronix 4025 insert-line
239 A Sample Entry
241 The following entry, which describes the Concept-100, is among the more
243 complex entries in the termcap file as of this writing.
244 ca|concept100|c100|concept|c104|concept100-4p|HDS Concept-100:\
246 :al=3∗\E^R:am:bl=^G:cd=16∗\E^C:ce=16\E^U:cl=2∗^L:cm=\Ea%+ %+ :\
247 :co#80:.cr=9^M:db:dc=16\E^A:dl=3∗\E^B:do=^J:ei=\E\200:eo:im=\E^P:in:\
248 :ip=16∗:is=\EU\Ef\E7\E5\E8\El\ENH\EK\E\200\Eo&\200\Eo\47\E:k1=\E5:\
249 :k2=\E6:k3=\E7:kb=^h:kd=\E<:ke=\Ex:kh=\E?:kl=\E>:kr=\E=:ks=\EX:\
250 :ku=\E;:le=^H:li#24:mb=\EC:me=\EN\200:mh=\EE:mi:mk=\EH:mp=\EI:\
251 :mr=\ED:nd=\E=:pb#9600:rp=0.2∗\Er%.%+ :se=\Ed\Ee:sf=^J:so=\EE\ED:\
252 :.ta=8\t:te=\Ev \200\200\200\200\200\200\Ep\r\n:\
253 :ti=\EU\Ev 8p\Ep\r:ue=\Eg:ul:up=\E;:us=\EG:\
254 :vb=\Ek\200\200\200\200\200\200\200\200\200\200\200\200\200\200\EK:\
255 :ve=\Ew:vs=\EW:vt#8:xn:\
256 :bs:cr=^M:dC#9:dT#8:nl=^J:ta=^I:pt:
257 Entries may continue onto multiple lines by giving a \ as the last
259 character of a line, and empty fields may be included for readability
260 (here between the last field on a line and the first field on the
261 next). Comments may be included on lines beginning with “#”.
262 Types of Capabilities
264 Capabilities in termcap are of three types: Boolean capabilities, which
266 indicate particular features that the terminal has; numeric capabili‐
267 ties, giving the size of the display or the size of other attributes;
268 and string capabilities, which give character sequences that can be
269 used to perform particular terminal operations. All capabilities have
270 two-letter codes. For instance, the fact that the Concept has auto‐
271 matic margins (i.e., an automatic return and linefeed when the end of a
272 line is reached) is indicated by the Boolean capability am. Hence the
273 description of the Concept includes am.
274 Numeric capabilities are followed by the character `#' then the value.
276 In the example above co, which indicates the number of columns the dis‐
277 play has, gives the value `80' for the Concept.
278 Finally, string-valued capabilities, such as ce (clear-to-end-of-line
280 sequence) are given by the two-letter code, an `=', then a string end‐
281 ing at the next following `:'. A delay in milliseconds may appear
282 after the `=' in such a capability, which causes padding characters to
283 be supplied by tputs after the remainder of the string is sent to pro‐
284 vide this delay. The delay can be either a number, e.g. `20', or a
285 number followed by an `∗', i.e., `3∗'. An `∗' indicates that the pad‐
286 ding required is proportional to the number of lines affected by the
287 operation, and the amount given is the per-affected-line padding
288 required. (In the case of insert-character, the factor is still the
289 number of lines affected; this is always 1 unless the terminal has in
290 and the software uses it.) When an `∗' is specified, it is sometimes
291 useful to give a delay of the form `3.5' to specify a delay per line to
292 tenths of milliseconds. (Only one decimal place is allowed.)
293 A number of escape sequences are provided in the string-valued capabil‐
295 ities for easy encoding of control characters there. \E maps to an ESC
296 character, ^X maps to a control-X for any appropriate X, and the
297 sequences \n \r \t \b \f map to linefeed, return, tab, backspace, and
298 formfeed, respectively. Finally, characters may be given as three
299 octal digits after a \, and the characters ^ and \ may be given as \^
300 and \\. If it is necessary to place a : in a capability it must be
301 escaped in octal as \072. If it is necessary to place a NUL character
302 in a string capability it must be encoded as \200. (The routines that
303 deal with termcap use C strings and strip the high bits of the output
304 very late, so that a \200 comes out as a \000 would.)
305 Sometimes individual capabilities must be commented out. To do this,
307 put a period before the capability name. For example, see the first cr
308 and ta in the example above.
309 Preparing Descriptions
311 We now outline how to prepare descriptions of terminals. The most
313 effective way to prepare a terminal description is by imitating the
314 description of a similar terminal in termcap and to build up a descrip‐
315 tion gradually, using partial descriptions with vi to check that they
316 are correct. Be aware that a very unusual terminal may expose defi‐
317 ciencies in the ability of the termcap file to describe it or bugs in
318 vi. To easily test a new terminal description you can set the environ‐
319 ment variable TERMCAP to the absolute pathname of a file containing the
320 description you are working on and programs will look there rather than
321 in /etc/termcap. TERMCAP can also be set to the termcap entry itself
322 to avoid reading the file when starting up a program.
323 To get the padding for insert-line right (if the terminal manufacturer
325 did not document it), a severe test is to use vi to edit /etc/passwd at
326 9600 baud, delete roughly 16 lines from the middle of the screen, then
327 hit the `u' key several times quickly. If the display messes up, more
328 padding is usually needed. A similar test can be used for insert-char‐
329 acter.
330 Basic Capabilities
332 The number of columns on each line of the display is given by the co
334 numeric capability. If the display is a CRT, then the number of lines
335 on the screen is given by the li capability. If the display wraps
336 around to the beginning of the next line when the cursor reaches the
337 right margin, then it should have the am capability. If the terminal
338 can clear its screen, the code to do this is given by the cl string
339 capability. If the terminal overstrikes (rather than clearing the
340 position when a character is overwritten), it should have the os capa‐
341 bility. If the terminal is a printing terminal, with no soft copy
342 unit, give it both hc and os. (os applies to storage scope terminals,
343 such as the Tektronix 4010 series, as well as to hard copy and APL ter‐
344 minals.) If there is a code to move the cursor to the left edge of the
345 current row, give this as cr. (Normally this will be carriage-return,
346 ^M.) If there is a code to produce an audible signal (bell, beep,
347 etc.), give this as bl.
348 If there is a code (such as backspace) to move the cursor one position
350 to the left, that capability should be given as le. Similarly, codes
351 to move to the right, up, and down should be given as nd, up, and do,
352 respectively. These local cursor motions should not alter the text
353 they pass over; for example, you would not normally use “nd= ” unless
354 the terminal has the os capability, because the space would erase the
355 character moved over.
356 A very important point here is that the local cursor motions encoded in
358 termcap have undefined behavior at the left and top edges of a CRT dis‐
359 play. Programs should never attempt to backspace around the left edge,
360 unless bw is given, and never attempt to go up off the top using local
361 cursor motions.
362 In order to scroll text up, a program goes to the bottom left corner of
364 the screen and sends the sf (index) string. To scroll text down, a
365 program goes to the top left corner of the screen and sends the sr
366 (reverse index) string. The strings sf and sr have undefined behavior
367 when not on their respective corners of the screen. Parameterized ver‐
368 sions of the scrolling sequences are SF and SR, which have the same
369 semantics as sf and sr except that they take one parameter and scroll
370 that many lines. They also have undefined behavior except at the
371 appropriate corner of the screen.
372 The am capability tells whether the cursor sticks at the right edge of
374 the screen when text is output there, but this does not necessarily
375 apply to nd from the last column. Leftward local motion is defined
376 from the left edge only when bw is given; then an le from the left edge
377 will move to the right edge of the previous row. This is useful for
378 drawing a box around the edge of the screen, for example. If the ter‐
379 minal has switch-selectable automatic margins, the termcap description
380 usually assumes that this feature is on, i.e., am. If the terminal has
381 a command that moves to the first column of the next line, that command
382 can be given as nw (newline). It is permissible for this to clear the
383 remainder of the current line, so if the terminal has no correctly-
384 working CR and LF it may still be possible to craft a working nw out of
385 one or both of them.
386 These capabilities suffice to describe hardcopy and “glass-tty” termi‐
388 nals. Thus the Teletype model 33 is described as
389 T3|tty33|33|tty|Teletype model 33:\
391 :bl=^G:co#72:cr=^M:do=^J:hc:os:
392 and the Lear Siegler ADM-3 is described as
394 l3|adm3|3|LSI ADM-3:\
396 :am:bl=^G:cl=^Z:co#80:cr=^M:do=^J:le=^H:li#24:sf=^J:
397 Parameterized Strings
399 Cursor addressing and other strings requiring parameters are described
401 by a parameterized string capability, with printf(3S)-like escapes %x
402 in it, while other characters are passed through unchanged. For exam‐
403 ple, to address the cursor the cm capability is given, using two param‐
404 eters: the row and column to move to. (Rows and columns are numbered
405 from zero and refer to the physical screen visible to the user, not to
406 any unseen memory. If the terminal has memory-relative cursor address‐
407 ing, that can be indicated by an analogous CM capability.)
408 The % encodings have the following meanings:
410 %% output `%'
412 %d output value as in printf %d
413 %2 output value as in printf %2d
414 %3 output value as in printf %3d
415 %. output value as in printf %c
416 %+x add x to value, then do %.
417 %>xy if value > x then add y, no output
418 %r reverse order of two parameters, no output
419 %i increment by one, no output
420 %n exclusive-or all parameters with 0140 (Datamedia 2500)
421 %B BCD (16∗(value/10)) + (value%10), no output
422 %D Reverse coding (value - 2∗(value%16)), no output (Delta Data)
423 Consider the Hewlett-Packard 2645, which, to get to row 3 and column
425 12, needs to be sent “\E&a12c03Y” padded for 6 milliseconds. Note that
426 the order of the row and column coordinates is reversed here and that
427 the row and column are sent as two-digit integers. Thus its cm capa‐
428 bility is “cm=6\E&%r%2c%2Y”.
429 The Microterm ACT-IV needs the current row and column sent simply
431 encoded in binary preceded by a ^T, “cm=^T%.%.”. Terminals that use
432 “%.” need to be able to backspace the cursor (le) and to move the cur‐
433 sor up one line on the screen (up). This is necessary because it is
434 not always safe to transmit \n, ^D, and \r, as the system may change or
435 discard them. (Programs using termcap must set terminal modes so that
436 tabs are not expanded, so \t is safe to send. This turns out to be
437 essential for the Ann Arbor 4080.)
438 A final example is the Lear Siegler ADM-3a, which offsets row and col‐
440 umn by a blank character, thus “cm=\E=%+ %+ ”.
441 Row or column absolute cursor addressing can be given as single parame‐
443 ter capabilities ch (horizontal position absolute) and cv (vertical
444 position absolute). Sometimes these are shorter than the more general
445 two-parameter sequence (as with the Hewlett-Packard 2645) and can be
446 used in preference to cm. If there are parameterized local motions
447 (e.g., move n positions to the right) these can be given as DO, LE, RI,
448 and UP with a single parameter indicating how many positions to move.
449 These are primarily useful if the terminal does not have cm, such as
450 the Tektronix 4025.
451 Cursor Motions
453 If the terminal has a fast way to home the cursor (to the very upper
455 left corner of the screen), this can be given as ho. Similarly, a fast
456 way of getting to the lower left-hand corner can be given as ll; this
457 may involve going up with up from the home position, but a program
458 should never do this itself (unless ll does), because it can make no
459 assumption about the effect of moving up from the home position. Note
460 that the home position is the same as cursor address (0,0): to the top
461 left corner of the screen, not of memory. (Therefore, the “\EH”
462 sequence on Hewlett-Packard terminals cannot be used for ho.)
463 Area Clears
465 If the terminal can clear from the current position to the end of the
467 line, leaving the cursor where it is, this should be given as ce. If
468 the terminal can clear from the current position to the end of the dis‐
469 play, this should be given as cd. cd must only be invoked from the
470 first column of a line. (Therefore, it can be simulated by a request
471 to delete a large number of lines, if a true cd is not available.)
472 Insert/Delete Line
474 If the terminal can open a new blank line before the line containing
476 the cursor, this should be given as al; this must be invoked only from
477 the first position of a line. The cursor must then appear at the left
478 of the newly blank line. If the terminal can delete the line that the
479 cursor is on, this should be given as dl; this must only be used from
480 the first position on the line to be deleted. Versions of al and dl
481 which take a single parameter and insert or delete that many lines can
482 be given as AL and DL. If the terminal has a settable scrolling region
483 (like the VT100), the command to set this can be described with the cs
484 capability, which takes two parameters: the top and bottom lines of the
485 scrolling region. The cursor position is, alas, undefined after using
486 this command. It is possible to get the effect of insert or delete
487 line using this command — the sc and rc (save and restore cursor) com‐
488 mands are also useful. Inserting lines at the top or bottom of the
489 screen can also be done using sr or sf on many terminals without a true
490 insert/delete line, and is often faster even on terminals with those
491 features.
492 If the terminal has the ability to define a window as part of memory
494 which all commands affect, it should be given as the parameterized
495 string wi. The four parameters are the starting and ending lines in
496 memory and the starting and ending columns in memory, in that order.
497 (This terminfo capability is described for completeness. It is
498 unlikely that any termcap-using program will support it.)
499 If the terminal can retain display memory above the screen, then the da
501 capability should be given; if display memory can be retained below,
502 then db should be given. These indicate that deleting a line or
503 scrolling may bring non-blank lines up from below or that scrolling
504 back with sr may bring down non-blank lines.
505 Insert/Delete Character
507 There are two basic kinds of intelligent terminals with respect to
509 insert/delete character that can be described using termcap. The most
510 common insert/delete character operations affect only the characters on
511 the current line and shift characters off the end of the line rigidly.
512 Other terminals, such as the Concept-100 and the Perkin Elmer Owl, make
513 a distinction between typed and untyped blanks on the screen, shifting
514 upon an insert or delete only to an untyped blank on the screen which
515 is either eliminated or expanded to two untyped blanks. You can deter‐
516 mine the kind of terminal you have by clearing the screen then typing
517 text separated by cursor motions. Type “abc def” using local cursor
518 motions (not spaces) between the “abc” and the “def”. Then position
519 the cursor before the “abc” and put the terminal in insert mode. If
520 typing characters causes the rest of the line to shift rigidly and
521 characters to fall off the end, then your terminal does not distinguish
522 between blanks and untyped positions. If the “abc” shifts over to the
523 “def” which then move together around the end of the current line and
524 onto the next as you insert, then you have the second type of terminal
525 and should give the capability in, which stands for “insert null”.
526 While these are two logically separate attributes (one line vs. multi-
527 line insert mode, and special treatment of untyped spaces), we have
528 seen no terminals whose insert mode cannot be described with the single
529 attribute.
530 Termcap can describe both terminals that have an insert mode and termi‐
532 nals that send a simple sequence to open a blank position on the cur‐
533 rent line. Give as im the sequence to get into insert mode. Give as
534 ei the sequence to leave insert mode. Now give as ic any sequence that
535 needs to be sent just before each character to be inserted. Most ter‐
536 minals with a true insert mode will not give ic; terminals that use a
537 sequence to open a screen position should give it here. (If your ter‐
538 minal has both, insert mode is usually preferable to ic. Do not give
539 both unless the terminal actually requires both to be used in combina‐
540 tion.) If post-insert padding is needed, give this as a number of mil‐
541 liseconds in ip (a string option). Any other sequence that may need to
542 be sent after insertion of a single character can also be given in ip.
543 If your terminal needs to be placed into an `insert mode' and needs a
544 special code preceding each inserted character, then both im/ei and ic
545 can be given, and both will be used. The IC capability, with one
546 parameter n, will repeat the effects of ic n times.
547 It is occasionally necessary to move around while in insert mode to
549 delete characters on the same line (e.g., if there is a tab after the
550 insertion position). If your terminal allows motion while in insert
551 mode, you can give the capability mi to speed up inserting in this
552 case. Omitting mi will affect only speed. Some terminals (notably
553 Datamedia's) must not have mi because of the way their insert mode
554 works.
555 Finally, you can specify dc to delete a single character, DC with one
557 parameter n to delete n characters, and delete mode by giving dm and ed
558 to enter and exit delete mode (which is any mode the terminal needs to
559 be placed in for dc to work).
560 Highlighting, Underlining, and Visible Bells
562 If your terminal has one or more kinds of display attributes, these can
564 be represented in a number of different ways. You should choose one
565 display form as standout mode, representing a good high-contrast, easy-
566 on-the-eyes format for highlighting error messages and other attention
567 getters. (If you have a choice, reverse video plus half-bright is
568 good, or reverse video alone.) The sequences to enter and exit stand‐
569 out mode are given as so and se, respectively. If the code to change
570 into or out of standout mode leaves one or even two blank spaces or
571 garbage characters on the screen, as the TVI 912 and Teleray 1061 do,
572 then sg should be given to tell how many characters are left.
573 Codes to begin underlining and end underlining can be given as us and
575 ue, respectively. Underline mode change garbage is specified by ug,
576 similar to sg. If the terminal has a code to underline the current
577 character and move the cursor one position to the right, such as the
578 Microterm Mime, this can be given as uc.
579 Other capabilities to enter various highlighting modes include mb
581 (blinking), md (bold or extra bright), mh (dim or half-bright), mk
582 (blanking or invisible text), mp (protected), mr (reverse video), me
583 (turn off all attribute modes), as (enter alternate character set
584 mode), and ae (exit alternate character set mode). Turning on any of
585 these modes singly may or may not turn off other modes.
586 If there is a sequence to set arbitrary combinations of mode, this
588 should be given as sa (set attributes), taking 9 parameters. Each
589 parameter is either 0 or 1, as the corresponding attributes is on or
590 off. The 9 parameters are, in order: standout, underline, reverse,
591 blink, dim, bold, blank, protect, and alternate character set. Not all
592 modes need be supported by sa, only those for which corresponding
593 attribute commands exist. (It is unlikely that a termcap-using program
594 will support this capability, which is defined for compatibility with
595 terminfo.)
596 Terminals with the “magic cookie” glitches (sg and ug), rather than
598 maintaining extra attribute bits for each character cell, instead
599 deposit special “cookies”, or “garbage characters”, when they receive
600 mode-setting sequences, which affect the display algorithm.
601 Some terminals, such as the Hewlett-Packard 2621, automatically leave
603 standout mode when they move to a new line or when the cursor is
604 addressed. Programs using standout mode should exit standout mode on
605 such terminals before moving the cursor or sending a newline. On ter‐
606 minals where this is not a problem, the ms capability should be present
607 to say that this overhead is unnecessary.
608 If the terminal has a way of flashing the screen to indicate an error
610 quietly (a bell replacement), this can be given as vb; it must not move
611 the cursor.
612 If the cursor needs to be made more visible than normal when it is not
614 on the bottom line (to change, for example, a non-blinking underline
615 into an easier-to-find block or blinking underline), give this sequence
616 as vs. If there is a way to make the cursor completely invisible, give
617 that as vi. The capability ve, which undoes the effects of both of
618 these modes, should also be given.
619 If your terminal correctly displays underlined characters (with no spe‐
621 cial codes needed) even though it does not overstrike, then you should
622 give the capability ul. If overstrikes are erasable with a blank, this
623 should be indicated by giving eo.
624 Keypad
626 If the terminal has a keypad that transmits codes when the keys are
628 pressed, this information can be given. Note that it is not possible
629 to handle terminals where the keypad only works in local mode (this
630 applies, for example, to the unshifted Hewlett-Packard 2621 keys). If
631 the keypad can be set to transmit or not transmit, give these codes as
632 ks and ke. Otherwise the keypad is assumed to always transmit. The
633 codes sent by the left-arrow, right-arrow, up-arrow, down-arrow, and
634 home keys can be given as kl, kr, ku, kd, and kh, respectively. If
635 there are function keys such as f0, f1, ..., f9, the codes they send
636 can be given as k0, k1,..., k9. If these keys have labels other than
637 the default f0 through f9, the labels can be given as l0, l1,..., l9.
638 The codes transmitted by certain other special keys can be given: kH
639 (home down), kb (backspace), ka (clear all tabs), kt (clear the tab
640 stop in this column), kC (clear screen or erase), kD (delete charac‐
641 ter), kL (delete line), kM (exit insert mode), kE (clear to end of
642 line), kS (clear to end of screen), kI (insert character or enter
643 insert mode), kA (insert line), kN (next page), kP (previous page), kF
644 (scroll forward/down), kR (scroll backward/up), and kT (set a tab stop
645 in this column). In addition, if the keypad has a 3 by 3 array of keys
646 including the four arrow keys, then the other five keys can be given as
647 K1, K2, K3, K4, and K5. These keys are useful when the effects of a 3
648 by 3 directional pad are needed. The obsolete ko capability formerly
649 used to describe “other” function keys has been completely supplanted
650 by the above capabilities.
651 The ma entry is also used to indicate arrow keys on terminals that have
653 single-character arrow keys. It is obsolete but still in use in ver‐
654 sion 2 of vi which must be run on some minicomputers due to memory lim‐
655 itations. This field is redundant with kl, kr, ku, kd, and kh. It
656 consists of groups of two characters. In each group, the first charac‐
657 ter is what an arrow key sends, and the second character is the corre‐
658 sponding vi command. These commands are h for kl, j for kd, k for ku,
659 l for kr, and H for kh. For example, the Mime would have
660 “ma=^Hh^Kj^Zk^Xl” indicating arrow keys left (^H), down (^K), up (^Z),
661 and right (^X). (There is no home key on the Mime.)
662 Tabs and Initialization
664 If the terminal needs to be in a special mode when running a program
666 that uses these capabilities, the codes to enter and exit this mode can
667 be given as ti and te. This arises, for example, from terminals like
668 the Concept with more than one page of memory. If the terminal has
669 only memory-relative cursor addressing and not screen-relative cursor
670 addressing, a screen-sized window must be fixed into the display for
671 cursor addressing to work properly. This is also used for the Tek‐
672 tronix 4025, where ti sets the command character to be the one used by
673 termcap.
674 Other capabilities include is, an initialization string for the termi‐
676 nal, and if, the name of a file containing long initialization strings.
677 These strings are expected to set the terminal into modes consistent
678 with the rest of the termcap description. They are normally sent to
679 the terminal by the tset program each time the user logs in. They will
680 be printed in the following order: is; setting tabs using ct and st;
681 and finally if. (Terminfo uses i1-i2 instead of is and runs the pro‐
682 gram iP and prints i3 after the other initializations.) A pair of
683 sequences that does a harder reset from a totally unknown state can be
684 analogously given as rs and if. These strings are output by the reset
685 program, which is used when the terminal gets into a wedged state.
686 (Terminfo uses r1-r3 instead of rs.) Commands are normally placed in
687 rs and rf only if they produce annoying effects on the screen and are
688 not necessary when logging in. For example, the command to set the
689 VT100 into 80-column mode would normally be part of is, but it causes
690 an annoying glitch of the screen and is not normally needed since the
691 terminal is usually already in 80-column mode.
692 If the terminal has hardware tabs, the command to advance to the next
694 tab stop can be given as ta (usually ^I). A “backtab” command which
695 moves leftward to the previous tab stop can be given as bt. By conven‐
696 tion, if the terminal driver modes indicate that tab stops are being
697 expanded by the computer rather than being sent to the terminal, pro‐
698 grams should not use ta or bt even if they are present, since the user
699 may not have the tab stops properly set. If the terminal has hardware
700 tabs that are initially set every n positions when the terminal is pow‐
701 ered up, then the numeric parameter it is given, showing the number of
702 positions between tab stops. This is normally used by the tset command
703 to determine whether to set the driver mode for hardware tab expansion,
704 and whether to set the tab stops. If the terminal has tab stops that
705 can be saved in nonvolatile memory, the termcap description can assume
706 that they are properly set.
707 If there are commands to set and clear tab stops, they can be given as
709 ct (clear all tab stops) and st (set a tab stop in the current column
710 of every row). If a more complex sequence is needed to set the tabs
711 than can be described by this, the sequence can be placed in is or if.
712 Delays
714 Certain capabilities control padding in the terminal driver. These are
716 primarily needed by hardcopy terminals and are used by the tset program
717 to set terminal driver modes appropriately. Delays embedded in the
718 capabilities cr, sf, le, ff, and ta will cause the appropriate delay
719 bits to be set in the terminal driver. If pb (padding baud rate) is
720 given, these values can be ignored at baud rates below the value of pb.
721 For 4.2BSD tset, the delays are given as numeric capabilities dC, dN,
722 dB, dF, and dT instead.
723 Miscellaneous
725 If the terminal requires other than a NUL (zero) character as a pad,
727 this can be given as pc. Only the first character of the pc string is
728 used.
729 If the terminal has commands to save and restore the position of the
731 cursor, give them as sc and rc.
732 If the terminal has an extra “status line” that is not normally used by
734 software, this fact can be indicated. If the status line is viewed as
735 an extra line below the bottom line, then the capability hs should be
736 given. Special strings to go to a position in the status line and to
737 return from the status line can be given as ts and fs. (fs must leave
738 the cursor position in the same place that it was before ts. If neces‐
739 sary, the sc and rc strings can be included in ts and fs to get this
740 effect.) The capability ts takes one parameter, which is the column
741 number of the status line to which the cursor is to be moved. If
742 escape sequences and other special commands such as tab work while in
743 the status line, the flag es can be given. A string that turns off the
744 status line (or otherwise erases its contents) should be given as ds.
745 The status line is normally assumed to be the same width as the rest of
746 the screen, i.e., co. If the status line is a different width (possi‐
747 bly because the terminal does not allow an entire line to be loaded),
748 then its width in columns can be indicated with the numeric parameter
749 ws.
750 If the terminal can move up or down half a line, this can be indicated
752 with hu (half-line up) and hd (half-line down). This is primarily use‐
753 ful for superscripts and subscripts on hardcopy terminals. If a hard‐
754 copy terminal can eject to the next page (form feed), give this as ff
755 (usually ^L).
756 If there is a command to repeat a given character a given number of
758 times (to save time transmitting a large number of identical charac‐
759 ters), this can be indicated with the parameterized string rp. The
760 first parameter is the character to be repeated and the second is the
761 number of times to repeat it. (This is a terminfo feature that is
762 unlikely to be supported by a program that uses termcap.)
763 If the terminal has a settable command character, such as the Tektronix
765 4025, this can be indicated with CC. A prototype command character is
766 chosen which is used in all capabilities. This character is given in
767 the CC capability to identify it. The following convention is sup‐
768 ported on some UNIX systems: The environment is to be searched for a CC
769 variable, and if found, all occurrences of the prototype character are
770 replaced by the character in the environment variable. This use of the
771 CC environment variable is a very bad idea, as it conflicts with
772 make(1).
773 Terminal descriptions that do not represent a specific kind of known
775 terminal, such as switch, dialup, patch, and network, should include
776 the gn (generic) capability so that programs can complain that they do
777 not know how to talk to the terminal. (This capability does not apply
778 to virtual terminal descriptions for which the escape sequences are
779 known.)
780 If the terminal uses xoff/xon (DC3/DC1) handshaking for flow control,
782 give xo. Padding information should still be included so that routines
783 can make better decisions about costs, but actual pad characters will
784 not be transmitted.
785 If the terminal has a “meta key” which acts as a shift key, setting the
787 8th bit of any character transmitted, then this fact can be indicated
788 with km. Otherwise, software will assume that the 8th bit is parity
789 and it will usually be cleared. If strings exist to turn this “meta
790 mode” on and off, they can be given as mm and mo.
791 If the terminal has more lines of memory than will fit on the screen at
793 once, the number of lines of memory can be indicated with lm. An
794 explicit value of 0 indicates that the number of lines is not fixed,
795 but that there is still more memory than fits on the screen.
796 If the terminal is one of those supported by the UNIX system virtual
798 terminal protocol, the terminal number can be given as vt.
799 Media copy strings which control an auxiliary printer connected to the
801 terminal can be given as ps: print the contents of the screen; pf: turn
802 off the printer; and po: turn on the printer. When the printer is on,
803 all text sent to the terminal will be sent to the printer. It is unde‐
804 fined whether the text is also displayed on the terminal screen when
805 the printer is on. A variation pO takes one parameter and leaves the
806 printer on for as many characters as the value of the parameter, then
807 turns the printer off. The parameter should not exceed 255. All text,
808 including pf, is transparently passed to the printer while pO is in
809 effect.
810 Strings to program function keys can be given as pk, pl, and px. Each
812 of these strings takes two parameters: the function key number to pro‐
813 gram (from 0 to 9) and the string to program it with. Function key
814 numbers out of this range may program undefined keys in a terminal-
815 dependent manner. The differences among the capabilities are that pk
816 causes pressing the given key to be the same as the user typing the
817 given string; pl causes the string to be executed by the terminal in
818 local mode; and px causes the string to be transmitted to the computer.
819 Unfortunately, due to lack of a definition for string parameters in
820 termcap, only terminfo supports these capabilities.
821 Glitches and Braindamage
823 Hazeltine terminals, which do not allow `~' characters to be displayed,
825 should indicate hz.
826 The nc capability, now obsolete, formerly indicated Datamedia termi‐
828 nals, which echo \r \n for carriage return then ignore a following
829 linefeed.
830 Terminals that ignore a linefeed immediately after an am wrap, such as
832 the Concept, should indicate xn.
833 If ce is required to get rid of standout (instead of merely writing
835 normal text on top of it), xs should be given.
836 Teleray terminals, where tabs turn all characters moved over to blanks,
838 should indicate xt (destructive tabs). This glitch is also taken to
839 mean that it is not possible to position the cursor on top of a “magic
840 cookie”, and that to erase standout mode it is necessary to use delete
841 and insert line.
842 The Beehive Superbee, which is unable to correctly transmit the ESC or
844 ^C characters, has xb, indicating that the “f1” key is used for ESC and
845 “f2” for ^C. (Only certain Superbees have this problem, depending on
846 the ROM.)
847 Other specific terminal problems may be corrected by adding more capa‐
849 bilities of the form xx.
850 Similar Terminals
852 If there are two very similar terminals, one can be defined as being
854 just like the other with certain exceptions. The string capability tc
855 can be given with the name of the similar terminal. This capability
856 must be last, and the combined length of the entries must not exceed
857 1024. The capabilities given before tc override those in the terminal
858 type invoked by tc. A capability can be canceled by placing xx@ to the
859 left of the tc invocation, where xx is the capability. For example,
860 the entry
861 hn|2621-nl:ks@:ke@:tc=2621:
863 defines a “2621-nl” that does not have the ks or ke capabilities, hence
865 does not turn on the function key labels when in visual mode. This is
866 useful for different modes for a terminal, or for different user pref‐
867 erences.
868
870 William Joy
871 Mark Horton added underlining and keypad support
872
874 /etc/termcap file containing terminal descriptions
875
877 ex(1), more(1), tset(1), ul(1), vi(1), curses(3X), printf(3S), term(7).
878
880 Note: termcap was replaced by terminfo in UNIX System V Release 2.0.
881 The transition will be relatively painless if capabilities flagged as
882 “obsolete” are avoided.
883 Lines and columns are now stored by the kernel as well as in the term‐
885 cap entry. Most programs now use the kernel information primarily; the
886 information in this file is used only if the kernel does not have any
887 information.
888 Vi allows only 256 characters for string capabilities, and the routines
890 in termlib(3) do not check for overflow of this buffer. The total
891 length of a single entry (excluding only escaped newlines) may not
892 exceed 1024.
893 Not all programs support all entries.
8953rd Berkeley Distribution 1 November 1985 TERMCAP(5)