summaryrefslogtreecommitdiffstats
path: root/upstream/opensuse-tumbleweed/man3/attr.3ncurses
blob: c354a5c253244d67602b8f8a3cafef82c899b155 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
'\" t
.\"***************************************************************************
.\" Copyright 2018-2023,2024 Thomas E. Dickey                                *
.\" Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
.\"                                                                          *
.\" Permission is hereby granted, free of charge, to any person obtaining a  *
.\" copy of this software and associated documentation files (the            *
.\" "Software"), to deal in the Software without restriction, including      *
.\" without limitation the rights to use, copy, modify, merge, publish,      *
.\" distribute, distribute with modifications, sublicense, and/or sell       *
.\" copies of the Software, and to permit persons to whom the Software is    *
.\" furnished to do so, subject to the following conditions:                 *
.\"                                                                          *
.\" The above copyright notice and this permission notice shall be included  *
.\" in all copies or substantial portions of the Software.                   *
.\"                                                                          *
.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
.\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
.\" IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
.\" DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
.\" OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
.\" THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
.\"                                                                          *
.\" Except as contained in this notice, the name(s) of the above copyright   *
.\" holders shall not be used in advertising or otherwise to promote the     *
.\" sale, use or other dealings in this Software without prior written       *
.\" authorization.                                                           *
.\"***************************************************************************
.\"
.\" $Id: curs_attr.3x,v 1.105 2024/04/27 17:54:42 tom Exp $
.TH attr 3NCURSES 2024-04-27 "ncurses 6.5" "Library calls"
.ie \n(.g \{\
.ds `` \(lq
.ds '' \(rq
.\}
.el \{\
.ie t .ds `` ``
.el   .ds `` ""
.ie t .ds '' ''
.el   .ds '' ""
.\}
.
.de bP
.ie n  .IP \(bu 4
.el    .IP \(bu 2
..
.\" ---------------------------------------------------------------------------
.SH NAME
\fB\%attr_get\fP,
\fB\%wattr_get\fP,
\fB\%attr_set\fP,
\fB\%wattr_set\fP,
\fB\%attr_off\fP,
\fB\%wattr_off\fP,
\fB\%attr_on\fP,
\fB\%wattr_on\fP,
\fB\%attroff\fP,
\fB\%wattroff\fP,
\fB\%attron\fP,
\fB\%wattron\fP,
\fB\%attrset\fP,
\fB\%wattrset\fP,
\fB\%chgat\fP,
\fB\%wchgat\fP,
\fB\%mvchgat\fP,
\fB\%mvwchgat\fP,
\fB\%color_set\fP,
\fB\%wcolor_set\fP,
\fB\%standend\fP,
\fB\%wstandend\fP,
\fB\%standout\fP,
\fB\%wstandout\fP \-
manipulate attributes of character cells in \fIcurses\fR windows
.\" ---------------------------------------------------------------------------
.SH SYNOPSIS
.nf
\fB#include <ncursesw/curses.h>
.PP
\fBint attr_get(attr_t *\fIattrs\fP, short *\fIpair\fP, void *\fIopts\fP);
\fBint wattr_get(WINDOW *\fIwin\fP, attr_t *\fIattrs\fP, short *\fIpair\fP,\fR \fPvoid *\fIopts\fP);
\fBint attr_set(attr_t \fIattrs\fP, short \fIpair\fP, void *\fIopts\fP);
\fBint wattr_set(WINDOW *\fIwin\fP, attr_t \fIattrs\fP, short \fIpair\fP, void *\fIopts\fP);
.PP
\fBint attr_off(attr_t \fIattrs\fP, void *\fIopts\fP);
\fBint wattr_off(WINDOW *\fIwin\fP, attr_t \fIattrs\fP, void *\fIopts\fP);
\fBint attr_on(attr_t \fIattrs\fP, void *\fIopts\fP);
\fBint wattr_on(WINDOW *\fIwin\fP, attr_t \fIattrs\fP, void *\fIopts\fP);
.PP
\fBint attroff(int \fIattrs\fP);
\fBint wattroff(WINDOW *\fIwin\fP, int \fIattrs\fP);
\fBint attron(int \fIattrs\fP);
\fBint wattron(WINDOW *\fIwin\fP, int \fIattrs\fP);
\fBint attrset(int \fIattrs\fP);
\fBint wattrset(WINDOW *\fIwin\fP, int \fIattrs\fP);
.PP
\fBint chgat(int \fIn\fP, attr_t \fIattr\fP, short \fIpair\fP,\fR \fPconst void *\fIopts\fP);
\fBint wchgat(WINDOW *\fIwin\fP,
      \fBint \fIn\fB, attr_t \fIattr\fB,\fR \fBshort \fIpair\fB, const void *\fIopts\fB);\fR
\fBint mvchgat(int \fIy\fB, int \fIx\fB,\fR
      \fBint \fIn\fB, attr_t \fIattr\fB, short \fIpair\fB, const void *\fIopts\fB);\fR
\fBint mvwchgat(WINDOW *\fIwin\fB, int \fIy\fB, int \fIx\fB,\fR
      \fBint \fIn\fB, attr_t \fIattr\fB, short \fIpair\fB, const void *\fIopts\fB);\fR
.PP
\fBint color_set(short \fIpair\fB, void* \fIopts\fB);\fR
\fBint wcolor_set(WINDOW *\fIwin\fB, short \fIpair\fB,\fR \fBvoid* \fIopts\fP);\fR
.PP
\fBint standend(void);\fP
\fBint wstandend(WINDOW *\fIwin\fB);\fR
\fBint standout(void);\fP
\fBint wstandout(WINDOW *\fIwin\fB);\fR
.fi
.\" ---------------------------------------------------------------------------
.SH DESCRIPTION
These routines manipulate the current attributes of the named window,
which then apply to all characters that are written into
the window with \fBwaddch\fP, \fBwaddstr\fP and \fBwprintw\fP.
Attributes are
a property of the character, and move with the character through any scrolling
and insert/delete line/character operations.
To the extent possible, they are
displayed as appropriate modifications to the graphic rendition of characters
put on the screen.
.PP
These routines do not affect the attributes used
when erasing portions of the window.
See \fB\%bkgd\fP(3NCURSES) for functions which modify the attributes used for
erasing and clearing.
.\" ---------------------------------------------------------------------------
.SS "Window Attributes"
There are two sets of functions:
.bP
functions for manipulating the window attributes and color:
\fBwattr_set\fP and \fBwattr_get\fP.
.bP
functions for manipulating only the window attributes (not color):
\fBwattr_on\fP and \fBwattr_off\fP.
.PP
The \fBwattr_set\fP function sets the current attributes
of the given window to \fIattrs\fP, with color specified by \fIpair\fP.
.PP
Use \fBwattr_get\fP to retrieve attributes for the given window.
.PP
Use \fBattr_on\fP and \fBwattr_on\fP to turn on window attributes, i.e.,
values OR'd together in \fIattr\fP,
without affecting other attributes.
Use \fBattr_off\fP and \fBwattr_off\fP to turn off window attributes,
again values OR'd together in \fIattr\fP,
without affecting other attributes.
.\" ---------------------------------------------------------------------------
.SS "Legacy Window Attributes"
The X/Open window attribute routines which \fIset\fP or \fIget\fP,
turn \fIon\fP or \fIoff\fP
are extensions of older routines
which assume that color pairs are OR'd into the attribute parameter.
These newer routines use similar names, because
X/Open simply added an underscore (\fB_\fP) for the newer names.
.PP
The \fBint\fP datatype used in the legacy routines is treated as if
it is the same size as \fBchtype\fP (used by \fB\%addch\fP(3NCURSES)).
It holds the common video attributes (such as bold, reverse),
as well as a few bits for color.
Those bits correspond to the \fBA_COLOR\fP symbol.
The \fBCOLOR_PAIR\fP macro provides a value which can be OR'd into
the attribute parameter.
For example,
as long as that value fits into the \fBA_COLOR\fP mask,
then these calls produce similar results:
.PP
.RS 4
.EX
attrset(A_BOLD | COLOR_PAIR(\fIpair\fP));
attr_set(A_BOLD, \fIpair\fP, NULL);
.EE
.RE
.PP
However, if the value does not fit, then the \fBCOLOR_PAIR\fP macro
uses only the bits that fit.
For example,
because in \fI\%ncurses\fP \fBA_COLOR\fP has eight (8) bits,
then \fBCOLOR_PAIR(\fI259\fB)\fR is 4
(i.e., 259 is 4 more than the limit 255).
.PP
The \fBPAIR_NUMBER\fP macro extracts a pair number from an \fBint\fP
(or \fBchtype\fP).
For example, the \fIinput\fP and \fIoutput\fP values in these statements
would be the same:
.PP
.RS 4
.EX
int value = A_BOLD | COLOR_PAIR(\fIinput\fP);
int \fIoutput\fP = PAIR_NUMBER(value);
.EE
.RE
.PP
The \fBattrset\fP routine is a legacy feature predating SVr4 curses
but kept in X/Open Curses for the same reason that SVr4 curses kept it:
compatibility.
.PP
The remaining \fBattr\fP* functions operate exactly like the corresponding
\fBattr_\fP* functions, except that they take arguments of type \fBint\fP
rather than \fBattr_t\fP.
.PP
There is no corresponding \fB\%attrget\fP function as such
in X/Open Curses,
although \fI\%ncurses\fP provides \fB\%getattrs\fP
(see \fB\%legacy\fP(3NCURSES)).
.\" ---------------------------------------------------------------------------
.SS "Change Character Rendition"
The routine \fBchgat\fP changes the attributes of a given number of characters
starting at the current cursor location of \fBstdscr\fP.
It does not update
the cursor and does not perform wrapping.
A character count of \-1 or greater
than the remaining window width means to change attributes all the way to the
end of the current line.
The \fBwchgat\fP function generalizes this to any window;
the \fBmvwchgat\fP function does a cursor move before acting.
.PP
In these functions,
the color \fIpair\fP argument is a color pair index
(as in the first argument of \fBinit_pair\fP, see \fB\%color\fP(3NCURSES)).
.\" ---------------------------------------------------------------------------
.SS "Change Window Color"
The routine \fBcolor_set\fP sets the current color of the given window to the
foreground/background combination described by the color \fIpair\fP parameter.
.\" ---------------------------------------------------------------------------
.SS Standout
The routine \fBstandout\fP is
the same as \fBattron(A_STANDOUT)\fP.
The routine \fBstandend\fP is the same
as \fBattrset(A_NORMAL)\fP or \fBattrset(0)\fP, that is, it turns off all
attributes.
.PP
X/Open Curses does not mark these \*(``restricted\*('', because
.bP
they have well established legacy use, and
.bP
there is no ambiguity about the way the attributes
might be combined with a color pair.
.\" ---------------------------------------------------------------------------
.SS "Video Attributes"
The following video attributes, defined in \fB<curses.h>\fP, can be passed to
the routines \fBattron\fP, \fBattroff\fP, and \fBattrset\fP, or OR'd with the
characters passed to \fBaddch\fP (see \fB\%addch\fP(3NCURSES)).
.PP
.ne 15
.RS
.TS
Lb Lb
Lb Lx.
Name	Description
_
A_NORMAL	Normal display (no highlight)
A_STANDOUT	T{
Best highlighting mode of the terminal
T}
A_UNDERLINE	Underlining
A_REVERSE	Reverse video
A_BLINK	Blinking
A_DIM	Half bright
A_BOLD	Extra bright or bold
A_PROTECT	Protected mode
A_INVIS	Invisible or blank mode
A_ALTCHARSET	Alternate character set
A_ITALIC	Italics (non-X/Open extension)
A_CHARTEXT	Bit-mask to extract a character
A_COLOR	T{
Bit-mask to extract a color (legacy routines)
T}
.TE
.RE
.PP
These video attributes are supported by \fBattr_on\fP and related functions
(which also support the attributes recognized by \fBattron\fP, etc.):
.PP
.RS
.TS
Lb Lb
Lb Lx.
Name	Description
_
WA_HORIZONTAL	Horizontal highlight
WA_LEFT	Left highlight
WA_LOW	Low highlight
WA_RIGHT	Right highlight
WA_TOP	Top highlight
WA_VERTICAL	Vertical highlight
.TE
.RE
.PP
The return values of many of these routines are not meaningful (they are
implemented as macro-expanded assignments and simply return their argument).
The SVr4 manual page claims (falsely) that these routines always return \fB1\fP.
.\" ---------------------------------------------------------------------------
.SH RETURN VALUE
All routines return the integer \fBOK\fP on success, or \fBERR\fP on failure.
.PP
X/Open Curses does not specify any error conditions.
.PP
This implementation
.bP
returns an error if the window pointer is null.
.bP
returns an error if the color pair parameter
for \fBwcolor_set\fP is outside the range 0..COLOR_PAIRS\-1.
.bP
does not return an error if either of the parameters of \fBwattr_get\fP
used for retrieving attribute or color pair values is \fBNULL\fP.
.PP
Functions prefixed with \*(``mv\*('' first perform cursor movement and
fail if the position
.RI ( y ,
.IR x )
is outside the window boundaries.
.\" ---------------------------------------------------------------------------
.SH NOTES
These functions may be macros:
.sp
.RS
\fBattroff\fP, \fBwattroff\fP, \fBattron\fP, \fBwattron\fP,
\fBattrset\fP, \fBwattrset\fP, \fBstandend\fP and \fBstandout\fP.
.RE
.PP
Color pair values can only be OR'd with attributes if the pair
number is less than 256.
The alternate functions such as \fBcolor_set\fP can pass a color pair
value directly.
However, \fI\%ncurses\fP ABI 4 and 5 simply OR this value
within the alternate functions.
You must use \fI\%ncurses\fP ABI 6 to support more than 256 color pairs.
.\" ---------------------------------------------------------------------------
.SH EXTENSIONS
This implementation provides the \fBA_ITALIC\fP attribute for terminals
which have the \fBenter_italics_mode\fP (\fBsitm\fP)
and \fBexit_italics_mode\fP (\fBritm\fP) capabilities.
Italics are not mentioned in X/Open Curses.
Unlike the other video attributes, \fBA_ITALIC\fP is unrelated
to the \fBset_attributes\fP capabilities.
This implementation makes the assumption that
\fBexit_attribute_mode\fP may also reset italics.
.PP
Each of the functions added by XSI Curses has a parameter \fIopts\fP,
which X/Open Curses still (after more than twenty years) documents
as reserved for future use, saying that it should be \fBNULL\fP.
This implementation uses that parameter in ABI 6 for the functions which
have a color pair parameter to support \fIextended color pairs\fP:
.bP
For functions which modify the color, e.g.,
\fBwattr_set\fP and \fBwattr_on\fP,
if \fIopts\fP is set it is treated as a pointer to \fBint\fP,
and used to set the color pair instead of the \fBshort\fP \fIpair\fP parameter.
.bP
For functions which retrieve the color, e.g.,
\fBwattr_get\fP,
if \fIopts\fP is set it is treated as a pointer to \fBint\fP,
and used to retrieve the color pair as an \fBint\fP value,
in addition to
retrieving it via the standard pointer to \fBshort\fP parameter.
.bP
For functions which turn attributes off, e.g.,
\fBwattr_off\fP,
the \fIopts\fP parameter is ignored except
except to check that it is \fBNULL\fP.
.\" ---------------------------------------------------------------------------
.SH PORTABILITY
These functions are described in X/Open Curses, Issue 4.
The standard defined the dedicated type for highlights,
\fBattr_t\fP, which was not defined in SVr4 curses.
The functions taking \fBattr_t\fP arguments were not supported under SVr4.
.PP
Very old versions of this library did not force an update of the screen
when changing the attributes.
Use \fBtouchwin\fP to force the screen to match the updated attributes.
.PP
X/Open Curses states that whether the traditional functions
\fBattron\fP/\fBattroff\fP/\fBattrset\fP can manipulate attributes other than
\fBA_BLINK\fP, \fBA_BOLD\fP, \fBA_DIM\fP, \fBA_REVERSE\fP, \fBA_STANDOUT\fP, or
\fBA_UNDERLINE\fP is \*(``unspecified\*(''.
Under this implementation as well as
SVr4 curses, these functions correctly manipulate all other highlights
(specifically, \fBA_ALTCHARSET\fP, \fBA_PROTECT\fP, and \fBA_INVIS\fP).
.PP
X/Open Curses added these entry points:
.sp
.RS
\fBattr_get\fP, \fBattr_on\fP,
\fBattr_off\fP, \fBattr_set\fP, \fBwattr_on\fP, \fBwattr_off\fP,
\fBwattr_get\fP, \fBwattr_set\fP
.RE
.PP
The new functions are intended to work with
a new series of highlight macros prefixed with \fBWA_\fP.
The older macros have direct counterparts in the newer set of names:
.PP
.RS
.ne 9
.TS
Lb Lb
Lb Lx.
Name	Description
_
WA_NORMAL	Normal display (no highlight)
WA_STANDOUT	T{
Best highlighting mode of the terminal
T}
WA_UNDERLINE	Underlining
WA_REVERSE	Reverse video
WA_BLINK	Blinking
WA_DIM	Half bright
WA_BOLD	Extra bright or bold
WA_ALTCHARSET	Alternate character set
.TE
.RE
.PP
X/Open Curses does not assign values to these symbols,
nor does it state whether or not they are related to the
similarly-named A_NORMAL, etc.:
.bP
X/Open Curses specifies that each pair of corresponding \fBA_\fP
and \fBWA_\fP-using functions operates on the same current-highlight
information.
.bP
However, in some implementations, those symbols have unrelated values.
.IP
For example, the Solaris \fIxpg4\fP (X/Open) curses declares
\fBattr_t\fP to be an unsigned short integer (16-bits),
while \fBchtype\fP is a unsigned integer (32-bits).
The \fBWA_\fP symbols in this case are different from the \fBA_\fP symbols
because they are used for a smaller datatype which does not
represent \fBA_CHARTEXT\fP or \fBA_COLOR\fP.
.IP
In this implementation (as in many others), the values happen to be
the same because it simplifies copying information between
\fBchtype\fP and \fBcchar_t\fP variables.
.bP
Because \fI\%ncurses\fP's \fBattr_t\fP can hold a color pair
(in the \fBA_COLOR\fP field),
a call to
\fBwattr_on\fP,
\fBwattr_off\fP, or
\fBwattr_set\fP
may alter the window's color.
If the color pair information in the attribute parameter is zero,
no change is made to the window's color.
.IP
This is consistent with SVr4 curses;
X/Open Curses does not specify this.
.PP
The X/Open Curses extended conformance level adds new highlights
\fBA_HORIZONTAL\fP, \fBA_LEFT\fP, \fBA_LOW\fP, \fBA_RIGHT\fP, \fBA_TOP\fP,
\fBA_VERTICAL\fP (and corresponding \fBWA_\fP macros for each).
As of August 2013,
no known terminal provides these highlights
(i.e., via the \fBsgr1\fP capability).
.\" ---------------------------------------------------------------------------
.SH HISTORY
X/Open Curses is largely based on SVr4 curses,
adding support for \*(``wide-characters\*('' (not specific to Unicode).
Some of the X/Open differences from SVr4 curses address the way
video attributes can be applied to wide-characters.
But aside from that, \fBattrset\fP and \fBattr_set\fP are similar.
SVr4 curses provided the basic features for manipulating video attributes.
However, earlier versions of curses provided a part of these features.
.PP
As seen in 2.8BSD, curses assumed 7-bit characters,
using the eighth bit of a byte to represent the \fIstandout\fP
feature (often implemented as bold and/or reverse video).
The BSD curses library provided functions \fBstandout\fP and \fBstandend\fP
which were carried along into X/Open Curses due to their pervasive use
in legacy applications.
.PP
Some terminals in the 1980s could support a variety of video attributes,
although the BSD curses library could do nothing with those.
System V (1983) provided an improved curses library.
It defined the \fBA_\fP symbols for use by applications to manipulate the
other attributes.
There are few useful references for the chronology.
.PP
Goodheart's book
\fIUNIX Curses Explained\fP (1991) describes SVr3 (1987),
commenting on several functions:
.bP
the \fBattron\fP, \fBattroff\fP, \fBattrset\fP functions
(and most of the functions found in SVr4 but not in BSD curses) were
introduced by System V,
.bP
the alternate character set feature with \fBA_ALTCHARSET\fP was
added in SVr2 and improved in SVr3 (by adding \fBacs_map[]\fP),
.bP
\fBstart_color\fP and related color-functions were introduced by System V.3.2,
.bP
pads, soft-keys were added in SVr3, and
.PP
Goodheart did not mention the background character or the \fBcchar_t\fP type.
Those are respectively SVr4 and X/Open features.
He did mention the \fBA_\fP constants, but did not indicate their values.
Those were not the same in different systems,
even for those marked as System V.
.PP
Different Unix systems used different sizes for the bit-fields in \fBchtype\fP
for \fIcharacters\fP and \fIcolors\fP, and took into account the different
integer sizes (32-bit versus 64-bit).
.PP
This table showing the number of bits for \fBA_COLOR\fP
and \fBA_CHARTEXT\fP
was gleaned from the curses header files for
various operating systems and architectures.
The inferred architecture and notes reflect
the format and size of the defined constants
as well as clues such as the alternate character set implementation.
A 32-bit library can be used on a 64-bit system,
but not necessarily the reverse.
.PP
.TS
Lb  Lb Lb  Cb  S   Lb
Lb2 Lb Lb2 Lb2 Lb2 Lb
L   L  L   L   L   Lx.
\&	\&	\&	Bits	\&
Year	System	Arch	Color	Char	Notes
_
1992	Solaris 5.2	32	6	17	SVr4 \fIcurses\fP
1992	HP-UX 9	32	no	8	SVr2 \fIcurses\fP
1992	AIX 3.2	32	no	23	SVr2 \fIcurses\fP
1994	OSF/1 r3	32	no	23	SVr2 \fIcurses\fP
1995	HP-UX 10.00	32	6	16	SVr3 \fIcurses_colr\fP
1995	HP-UX 10.00	32	6	8	SVr4, X/Open \fIcurses\fP
1995	Solaris 5.4	32/64	7	16	X/Open \fIcurses\fP
1996	AIX 4.2	32	7	16	X/Open \fIcurses\fP
1996	OSF/1 r4	32	6	16	X/Open \fIcurses\fP
1997	HP-UX 11.00	32	6	8	X/Open \fIcurses\fP
2000	U/Win	32/64	7/31	16	uses \fIchtype\fP
.TE
.PP
Notes:
.RS 3
.PP
Regarding HP-UX,
.bP
HP-UX 10.20 (1996) added support for 64-bit PA-RISC processors in 1996.
.bP
HP-UX 10.30 (1997) marked \*(``curses_colr\*('' obsolete.
That version of curses was dropped with HP-UX 11.30 in 2006.
.PP
Regarding OSF/1 (and Tru64),
.bP
These used 64-bit hardware.
Like \fI\%ncurses\fP,
the OSF/1 curses interface is not customized for 32-bit and 64-bit
versions.
.bP
Unlike other systems which evolved from AT&T code,
OSF/1 provided a new implementation for X/Open curses.
.PP
Regarding Solaris,
.bP
The initial release of Solaris was in 1992.
.bP
The \fIxpg4\fP (X/Open) curses was developed by MKS from 1990 to 1995.
Sun's copyright began in 1996.
.bP
Sun updated the X/Open curses interface
after 64-bit support was introduced in 1997,
but did not modify the SVr4 curses interface.
.PP
Regarding U/Win,
.bP
Development of the curses library began in 1991, stopped in 2000.
.bP
Color support was added in 1998.
.bP
The library uses only \fBchtype\fP (no \fBcchar_t\fP).
.RE
.PP
Once X/Open curses was adopted in the mid-1990s, the constraint of
a 32-bit interface with many colors and wide-characters for \fBchtype\fP
became a moot point.
The \fBcchar_t\fP structure (whose size and
members are not specified in X/Open Curses) could be extended as needed.
.PP
Other interfaces are rarely used now:
.bP
BSD curses was improved slightly in 1993/1994 using Keith Bostic's
modification to make the library 8-bit clean for \fBnvi\fP(1).
He moved \fIstandout\fP attribute to a structure member.
.IP
The resulting 4.4BSD curses was replaced by \fI\%ncurses\fP over the
next ten years.
.bP
U/Win is rarely used now.
.\" ---------------------------------------------------------------------------
.SH SEE ALSO
\fB\%ncurses\fP(3NCURSES),
\fB\%addch\fP(3NCURSES),
\fB\%addstr\fP(3NCURSES),
\fB\%bkgd\fP(3NCURSES),
\fB\%printw\fP(3NCURSES),
\fB\%curses_variables\fP(3NCURSES)