-
Notifications
You must be signed in to change notification settings - Fork 88
/
line.c
1366 lines (1252 loc) · 28 KB
/
line.c
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
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*@@copyright@@*/
/*
* Routines to manipulate the "line buffer".
* The line buffer holds a line of output as it is being built
* in preparation for output to the screen.
*/
#include "less.h"
#include "charset.h"
#include "position.h"
#if MSDOS_COMPILER==WIN32C
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif
static char *linebuf = NULL; /* Buffer which holds the current output line */
static char *attr = NULL; /* Extension of linebuf to hold attributes */
public int size_linebuf = 0; /* Size of line buffer (and attr buffer) */
static int cshift; /* Current left-shift of output line buffer */
public int hshift; /* Desired left-shift of output line buffer */
public int tabstops[TABSTOP_MAX] = { 0 }; /* Custom tabstops */
public int ntabstops = 1; /* Number of tabstops */
public int tabdefault = 8; /* Default repeated tabstops */
public POSITION highest_hilite; /* Pos of last hilite in file found so far */
static int curr; /* Index into linebuf */
static int column; /* Printable length, accounting for
backspaces, etc. */
static int right_curr;
static int right_column;
static int overstrike; /* Next char should overstrike previous char */
static int last_overstrike = AT_NORMAL;
static int is_null_line; /* There is no current line */
static int lmargin; /* Left margin */
static LWCHAR pendc;
static POSITION pendpos;
static char *end_ansi_chars;
static char *mid_ansi_chars;
static int attr_swidth LESSPARAMS ((int a));
static int attr_ewidth LESSPARAMS ((int a));
static int do_append LESSPARAMS ((LWCHAR ch, char *rep, POSITION pos));
extern int sigs;
extern int bs_mode;
extern int linenums;
extern int ctldisp;
extern int twiddle;
extern int binattr;
extern int status_col;
extern int auto_wrap, ignaw;
extern int bo_s_width, bo_e_width;
extern int ul_s_width, ul_e_width;
extern int bl_s_width, bl_e_width;
extern int so_s_width, so_e_width;
extern int sc_width, sc_height;
extern int utf_mode;
extern POSITION start_attnpos;
extern POSITION end_attnpos;
extern LWCHAR rscroll_char;
extern int rscroll_attr;
static char mbc_buf[MAX_UTF_CHAR_LEN];
static int mbc_buf_len = 0;
static int mbc_buf_index = 0;
static POSITION mbc_pos;
/*
* Initialize from environment variables.
*/
public void
init_line()
{
end_ansi_chars = lgetenv("LESSANSIENDCHARS");
if (end_ansi_chars == NULL || *end_ansi_chars == '\0')
end_ansi_chars = "m";
mid_ansi_chars = lgetenv("LESSANSIMIDCHARS");
if (mid_ansi_chars == NULL || *mid_ansi_chars == '\0')
mid_ansi_chars = "0123456789:;[?!\"'#%()*+ ";
linebuf = (char *) ecalloc(LINEBUF_SIZE, sizeof(char));
attr = (char *) ecalloc(LINEBUF_SIZE, sizeof(char));
size_linebuf = LINEBUF_SIZE;
}
/*
* Expand the line buffer.
*/
static int
expand_linebuf()
{
/* Double the size of the line buffer. */
int new_size = size_linebuf * 2;
/* Just realloc to expand the buffer, if we can. */
#if HAVE_REALLOC
char *new_buf = (char *) realloc(linebuf, new_size);
char *new_attr = (char *) realloc(attr, new_size);
#else
char *new_buf = (char *) calloc(new_size, sizeof(char));
char *new_attr = (char *) calloc(new_size, sizeof(char));
#endif
if (new_buf == NULL || new_attr == NULL)
{
if (new_attr != NULL)
free(new_attr);
if (new_buf != NULL)
free(new_buf);
return 1;
}
#if HAVE_REALLOC
/*
* We realloc'd the buffers; they already have the old contents.
*/
#if 0
memset(new_buf + size_linebuf, 0, new_size - size_linebuf);
memset(new_attr + size_linebuf, 0, new_size - size_linebuf);
#endif
#else
/*
* We just calloc'd the buffers; copy the old contents.
*/
memcpy(new_buf, linebuf, size_linebuf * sizeof(char));
memcpy(new_attr, attr, size_linebuf * sizeof(char));
free(attr);
free(linebuf);
#endif
linebuf = new_buf;
attr = new_attr;
size_linebuf = new_size;
return 0;
}
/*
* Is a character ASCII?
*/
public int
is_ascii_char(ch)
LWCHAR ch;
{
return (ch <= 0x7F);
}
/*
* Rewind the line buffer.
*/
public void
prewind()
{
curr = 0;
column = 0;
right_curr = 0;
right_column = 0;
cshift = 0;
overstrike = 0;
last_overstrike = AT_NORMAL;
mbc_buf_len = 0;
is_null_line = 0;
pendc = '\0';
lmargin = 0;
if (status_col)
lmargin += 2;
}
/*
* Set a character in the line buffer.
*/
static void
set_linebuf(n, ch, a)
int n;
LWCHAR ch;
char a;
{
linebuf[n] = ch;
attr[n] = a;
}
/*
* Append a character to the line buffer.
*/
static void
add_linebuf(ch, a, w)
LWCHAR ch;
char a;
int w;
{
set_linebuf(curr++, ch, a);
column += w;
}
/*
* Insert the line number (of the given position) into the line buffer.
*/
public void
plinenum(pos)
POSITION pos;
{
LINENUM linenum = 0;
int i;
if (linenums == OPT_ONPLUS)
{
/*
* Get the line number and put it in the current line.
* {{ Note: since find_linenum calls forw_raw_line,
* it may seek in the input file, requiring the caller
* of plinenum to re-seek if necessary. }}
* {{ Since forw_raw_line modifies linebuf, we must
* do this first, before storing anything in linebuf. }}
*/
linenum = find_linenum(pos);
}
/*
* Display a status column if the -J option is set.
*/
if (status_col)
{
int a = AT_NORMAL;
char c = posmark(pos);
if (c != 0)
a |= AT_HILITE;
else
{
c = ' ';
if (start_attnpos != NULL_POSITION &&
pos >= start_attnpos && pos <= end_attnpos)
a |= AT_HILITE;
}
add_linebuf(c, a, 1); /* column 0: status */
add_linebuf(' ', AT_NORMAL, 1); /* column 1: empty */
}
/*
* Display the line number at the start of each line
* if the -N option is set.
*/
if (linenums == OPT_ONPLUS)
{
char buf[INT_STRLEN_BOUND(linenum) + 2];
int pad = 0;
int n;
linenumtoa(linenum, buf);
n = (int) strlen(buf);
if (n < MIN_LINENUM_WIDTH)
pad = MIN_LINENUM_WIDTH - n;
for (i = 0; i < pad; i++)
add_linebuf(' ', AT_NORMAL, 1);
for (i = 0; i < n; i++)
add_linebuf(buf[i], AT_BOLD, 1);
add_linebuf(' ', AT_NORMAL, 1);
lmargin += n + pad + 1;
}
/*
* Append enough spaces to bring us to the lmargin.
*/
while (column < lmargin)
{
add_linebuf(' ', AT_NORMAL, 1);
}
}
/*
* Shift the input line left.
* This means discarding N printable chars at the start of the buffer.
*/
static void
pshift(shift)
int shift;
{
LWCHAR prev_ch = 0;
unsigned char c;
int shifted = 0;
int to;
int from;
int len;
int width;
int prev_attr;
int next_attr;
if (shift > column - lmargin)
shift = column - lmargin;
if (shift > curr - lmargin)
shift = curr - lmargin;
to = from = lmargin;
/*
* We keep on going when shifted == shift
* to get all combining chars.
*/
while (shifted <= shift && from < curr)
{
c = linebuf[from];
if (ctldisp == OPT_ONPLUS && IS_CSI_START(c))
{
/* Keep cumulative effect. */
linebuf[to] = c;
attr[to++] = attr[from++];
while (from < curr && linebuf[from])
{
linebuf[to] = linebuf[from];
attr[to++] = attr[from];
if (!is_ansi_middle(linebuf[from++]))
break;
}
continue;
}
width = 0;
if (!IS_ASCII_OCTET(c) && utf_mode)
{
/* Assumes well-formedness validation already done. */
LWCHAR ch;
len = utf_len(c);
if (from + len > curr)
break;
ch = get_wchar(linebuf + from);
if (!is_composing_char(ch) && !is_combining_char(prev_ch, ch))
width = is_wide_char(ch) ? 2 : 1;
prev_ch = ch;
} else
{
len = 1;
if (c == '\b')
/* XXX - Incorrect if several '\b' in a row. */
width = (utf_mode && is_wide_char(prev_ch)) ? -2 : -1;
else if (!control_char(c))
width = 1;
prev_ch = 0;
}
if (width == 2 && shift - shifted == 1) {
/* Should never happen when called by pshift_all(). */
attr[to] = attr[from];
/*
* Assume a wide_char will never be the first half of a
* combining_char pair, so reset prev_ch in case we're
* followed by a '\b'.
*/
prev_ch = linebuf[to++] = ' ';
from += len;
shifted++;
continue;
}
/* Adjust width for magic cookies. */
prev_attr = (to > 0) ? attr[to-1] : AT_NORMAL;
next_attr = (from + len < curr) ? attr[from + len] : prev_attr;
if (!is_at_equiv(attr[from], prev_attr) &&
!is_at_equiv(attr[from], next_attr))
{
width += attr_swidth(attr[from]);
if (from + len < curr)
width += attr_ewidth(attr[from]);
if (is_at_equiv(prev_attr, next_attr))
{
width += attr_ewidth(prev_attr);
if (from + len < curr)
width += attr_swidth(next_attr);
}
}
if (shift - shifted < width)
break;
from += len;
shifted += width;
if (shifted < 0)
shifted = 0;
}
while (from < curr)
{
linebuf[to] = linebuf[from];
attr[to++] = attr[from++];
}
curr = to;
column -= shifted;
cshift += shifted;
}
/*
*
*/
public void
pshift_all()
{
pshift(column);
}
/*
* Return the printing width of the start (enter) sequence
* for a given character attribute.
*/
static int
attr_swidth(a)
int a;
{
int w = 0;
a = apply_at_specials(a);
if (a & AT_UNDERLINE)
w += ul_s_width;
if (a & AT_BOLD)
w += bo_s_width;
if (a & AT_BLINK)
w += bl_s_width;
if (a & AT_STANDOUT)
w += so_s_width;
return w;
}
/*
* Return the printing width of the end (exit) sequence
* for a given character attribute.
*/
static int
attr_ewidth(a)
int a;
{
int w = 0;
a = apply_at_specials(a);
if (a & AT_UNDERLINE)
w += ul_e_width;
if (a & AT_BOLD)
w += bo_e_width;
if (a & AT_BLINK)
w += bl_e_width;
if (a & AT_STANDOUT)
w += so_e_width;
return w;
}
/*
* Return the printing width of a given character and attribute,
* if the character were added to the current position in the line buffer.
* Adding a character with a given attribute may cause an enter or exit
* attribute sequence to be inserted, so this must be taken into account.
*/
static int
pwidth(ch, a, prev_ch)
LWCHAR ch;
int a;
LWCHAR prev_ch;
{
int w;
if (ch == '\b')
/*
* Backspace moves backwards one or two positions.
* XXX - Incorrect if several '\b' in a row.
*/
return (utf_mode && is_wide_char(prev_ch)) ? -2 : -1;
if (!utf_mode || is_ascii_char(ch))
{
if (control_char((char)ch))
{
/*
* Control characters do unpredictable things,
* so we don't even try to guess; say it doesn't move.
* This can only happen if the -r flag is in effect.
*/
return (0);
}
} else
{
if (is_composing_char(ch) || is_combining_char(prev_ch, ch))
{
/*
* Composing and combining chars take up no space.
*
* Some terminals, upon failure to compose a
* composing character with the character(s) that
* precede(s) it will actually take up one column
* for the composing character; there isn't much
* we could do short of testing the (complex)
* composition process ourselves and printing
* a binary representation when it fails.
*/
return (0);
}
}
/*
* Other characters take one or two columns,
* plus the width of any attribute enter/exit sequence.
*/
w = 1;
if (is_wide_char(ch))
w++;
if (curr > 0 && !is_at_equiv(attr[curr-1], a))
w += attr_ewidth(attr[curr-1]);
if ((apply_at_specials(a) != AT_NORMAL) &&
(curr == 0 || !is_at_equiv(attr[curr-1], a)))
w += attr_swidth(a);
return (w);
}
/*
* Delete to the previous base character in the line buffer.
* Return 1 if one is found.
*/
static int
backc()
{
LWCHAR prev_ch;
char *p = linebuf + curr;
LWCHAR ch = step_char(&p, -1, linebuf + lmargin);
int width;
/* This assumes that there is no '\b' in linebuf. */
while ( curr > lmargin
&& column > lmargin
&& (!(attr[curr - 1] & (AT_ANSI|AT_BINARY))))
{
curr = (int) (p - linebuf);
prev_ch = step_char(&p, -1, linebuf + lmargin);
width = pwidth(ch, attr[curr], prev_ch);
column -= width;
if (width > 0)
return 1;
ch = prev_ch;
}
return 0;
}
/*
* Are we currently within a recognized ANSI escape sequence?
*/
static int
in_ansi_esc_seq()
{
char *p;
/*
* Search backwards for either an ESC (which means we ARE in a seq);
* or an end char (which means we're NOT in a seq).
*/
for (p = &linebuf[curr]; p > linebuf; )
{
LWCHAR ch = step_char(&p, -1, linebuf);
if (IS_CSI_START(ch))
return (1);
if (!is_ansi_middle(ch))
return (0);
}
return (0);
}
/*
* Is a character the end of an ANSI escape sequence?
*/
public int
is_ansi_end(ch)
LWCHAR ch;
{
if (!is_ascii_char(ch))
return (0);
return (strchr(end_ansi_chars, (char) ch) != NULL);
}
/*
* Can a char appear in an ANSI escape sequence, before the end char?
*/
public int
is_ansi_middle(ch)
LWCHAR ch;
{
if (!is_ascii_char(ch))
return (0);
if (is_ansi_end(ch))
return (0);
return (strchr(mid_ansi_chars, (char) ch) != NULL);
}
/*
* Skip past an ANSI escape sequence.
* pp is initially positioned just after the CSI_START char.
*/
public void
skip_ansi(pp, limit)
char **pp;
constant char *limit;
{
LWCHAR c;
do {
c = step_char(pp, +1, limit);
} while (*pp < limit && is_ansi_middle(c));
/* Note that we discard final char, for which is_ansi_middle is false. */
}
/*
* Append a character and attribute to the line buffer.
*/
#define STORE_CHAR(ch,a,rep,pos) \
do { \
if (store_char((ch),(a),(rep),(pos))) return (1); \
} while (0)
static int
store_char(ch, a, rep, pos)
LWCHAR ch;
int a;
char *rep;
POSITION pos;
{
int w;
int replen;
char cs;
w = (a & (AT_UNDERLINE|AT_BOLD)); /* Pre-use w. */
if (w != AT_NORMAL)
last_overstrike = w;
#if HILITE_SEARCH
{
int matches;
if (is_hilited(pos, pos+1, 0, &matches))
{
/*
* This character should be highlighted.
* Override the attribute passed in.
*/
if (a != AT_ANSI)
{
if (highest_hilite != NULL_POSITION &&
pos > highest_hilite)
highest_hilite = pos;
a |= AT_HILITE;
}
}
}
#endif
if (ctldisp == OPT_ONPLUS && in_ansi_esc_seq())
{
if (!is_ansi_end(ch) && !is_ansi_middle(ch)) {
/* Remove whole unrecognized sequence. */
char *p = &linebuf[curr];
LWCHAR bch;
do {
bch = step_char(&p, -1, linebuf);
} while (p > linebuf && !IS_CSI_START(bch));
curr = (int) (p - linebuf);
return 0;
}
a = AT_ANSI; /* Will force re-AT_'ing around it. */
w = 0;
}
else if (ctldisp == OPT_ONPLUS && IS_CSI_START(ch))
{
a = AT_ANSI; /* Will force re-AT_'ing around it. */
w = 0;
}
else
{
char *p = &linebuf[curr];
LWCHAR prev_ch = step_char(&p, -1, linebuf);
w = pwidth(ch, a, prev_ch);
}
if (ctldisp != OPT_ON && column + w + attr_ewidth(a) > sc_width)
/*
* Won't fit on screen.
*/
return (1);
if (rep == NULL)
{
cs = (char) ch;
rep = &cs;
replen = 1;
} else
{
replen = utf_len(rep[0]);
}
if (curr + replen >= size_linebuf-6)
{
/*
* Won't fit in line buffer.
* Try to expand it.
*/
if (expand_linebuf())
return (1);
}
if (column > right_column && w > 0)
{
right_column = column;
right_curr = curr;
}
while (replen-- > 0)
{
add_linebuf(*rep++, a, 0);
}
column += w;
return (0);
}
/*
* Append a tab to the line buffer.
* Store spaces to represent the tab.
*/
#define STORE_TAB(a,pos) \
do { if (store_tab((a),(pos))) return (1); } while (0)
static int
store_tab(attr, pos)
int attr;
POSITION pos;
{
int to_tab = column + cshift - lmargin;
int i;
if (ntabstops < 2 || to_tab >= tabstops[ntabstops-1])
to_tab = tabdefault -
((to_tab - tabstops[ntabstops-1]) % tabdefault);
else
{
for (i = ntabstops - 2; i >= 0; i--)
if (to_tab >= tabstops[i])
break;
to_tab = tabstops[i+1] - to_tab;
}
if (column + to_tab - 1 + pwidth(' ', attr, 0) + attr_ewidth(attr) > sc_width)
return 1;
do {
STORE_CHAR(' ', attr, " ", pos);
} while (--to_tab > 0);
return 0;
}
#define STORE_PRCHAR(c, pos) \
do { if (store_prchar((c), (pos))) return 1; } while (0)
static int
store_prchar(c, pos)
LWCHAR c;
POSITION pos;
{
char *s;
/*
* Convert to printable representation.
*/
s = prchar(c);
/*
* Make sure we can get the entire representation
* of the character on this line.
*/
if (column + (int) strlen(s) - 1 +
pwidth(' ', binattr, 0) + attr_ewidth(binattr) > sc_width)
return 1;
for ( ; *s != 0; s++)
STORE_CHAR(*s, AT_BINARY, NULL, pos);
return 0;
}
static int
flush_mbc_buf(pos)
POSITION pos;
{
int i;
for (i = 0; i < mbc_buf_index; i++)
if (store_prchar(mbc_buf[i], pos))
return mbc_buf_index - i;
return 0;
}
/*
* Append a character to the line buffer.
* Expand tabs into spaces, handle underlining, boldfacing, etc.
* Returns 0 if ok, 1 if couldn't fit in buffer.
*/
public int
pappend(c, pos)
unsigned char c;
POSITION pos;
{
int r;
if (pendc)
{
if (c == '\r' && pendc == '\r')
return (0);
if (do_append(pendc, NULL, pendpos))
/*
* Oops. We've probably lost the char which
* was in pendc, since caller won't back up.
*/
return (1);
pendc = '\0';
}
if (c == '\r' && bs_mode == BS_SPECIAL)
{
if (mbc_buf_len > 0) /* utf_mode must be on. */
{
/* Flush incomplete (truncated) sequence. */
r = flush_mbc_buf(mbc_pos);
mbc_buf_index = r + 1;
mbc_buf_len = 0;
if (r)
return (mbc_buf_index);
}
/*
* Don't put the CR into the buffer until we see
* the next char. If the next char is a newline,
* discard the CR.
*/
pendc = c;
pendpos = pos;
return (0);
}
if (!utf_mode)
{
r = do_append(c, NULL, pos);
} else
{
/* Perform strict validation in all possible cases. */
if (mbc_buf_len == 0)
{
retry:
mbc_buf_index = 1;
*mbc_buf = c;
if (IS_ASCII_OCTET(c))
r = do_append(c, NULL, pos);
else if (IS_UTF8_LEAD(c))
{
mbc_buf_len = utf_len(c);
mbc_pos = pos;
return (0);
} else
/* UTF8_INVALID or stray UTF8_TRAIL */
r = flush_mbc_buf(pos);
} else if (IS_UTF8_TRAIL(c))
{
mbc_buf[mbc_buf_index++] = c;
if (mbc_buf_index < mbc_buf_len)
return (0);
if (is_utf8_well_formed(mbc_buf, mbc_buf_index))
r = do_append(get_wchar(mbc_buf), mbc_buf, mbc_pos);
else
/* Complete, but not shortest form, sequence. */
mbc_buf_index = r = flush_mbc_buf(mbc_pos);
mbc_buf_len = 0;
} else
{
/* Flush incomplete (truncated) sequence. */
r = flush_mbc_buf(mbc_pos);
mbc_buf_index = r + 1;
mbc_buf_len = 0;
/* Handle new char. */
if (!r)
goto retry;
}
}
/*
* If we need to shift the line, do it.
* But wait until we get to at least the middle of the screen,
* so shifting it doesn't affect the chars we're currently
* pappending. (Bold & underline can get messed up otherwise.)
*/
if (cshift < hshift && column > sc_width / 2)
{
linebuf[curr] = '\0';
pshift(hshift - cshift);
}
if (r)
{
/* How many chars should caller back up? */
r = (!utf_mode) ? 1 : mbc_buf_index;
}
return (r);
}
static int
do_append(ch, rep, pos)
LWCHAR ch;
char *rep;
POSITION pos;
{
int a;
LWCHAR prev_ch;
a = AT_NORMAL;
if (ch == '\b')
{
if (bs_mode == BS_CONTROL)
goto do_control_char;
/*
* A better test is needed here so we don't
* backspace over part of the printed
* representation of a binary character.
*/
if ( curr <= lmargin
|| column <= lmargin
|| (attr[curr - 1] & (AT_ANSI|AT_BINARY)))
STORE_PRCHAR('\b', pos);
else if (bs_mode == BS_NORMAL)
STORE_CHAR(ch, AT_NORMAL, NULL, pos);
else if (bs_mode == BS_SPECIAL)
overstrike = backc();
return 0;
}
if (overstrike > 0)
{
/*
* Overstrike the character at the current position
* in the line buffer. This will cause either
* underline (if a "_" is overstruck),
* bold (if an identical character is overstruck),
* or just deletion of the character in the buffer.
*/
overstrike = utf_mode ? -1 : 0;
if (utf_mode)
{
/* To be correct, this must be a base character. */
prev_ch = get_wchar(linebuf + curr);
} else
{
prev_ch = (unsigned char) linebuf[curr];
}
a = attr[curr];
if (ch == prev_ch)
{
/*
* Overstriking a char with itself means make it bold.
* But overstriking an underscore with itself is
* ambiguous. It could mean make it bold, or
* it could mean make it underlined.
* Use the previous overstrike to resolve it.
*/
if (ch == '_')
{
if ((a & (AT_BOLD|AT_UNDERLINE)) != AT_NORMAL)
a |= (AT_BOLD|AT_UNDERLINE);
else if (last_overstrike != AT_NORMAL)
a |= last_overstrike;
else
a |= AT_BOLD;
} else
a |= AT_BOLD;
} else if (ch == '_')
{
a |= AT_UNDERLINE;
ch = prev_ch;
rep = linebuf + curr;
} else if (prev_ch == '_')
{
a |= AT_UNDERLINE;
}
/* Else we replace prev_ch, but we keep its attributes. */
} else if (overstrike < 0)
{
if ( is_composing_char(ch)
|| is_combining_char(get_wchar(linebuf + curr), ch))
/* Continuation of the same overstrike. */
a = last_overstrike;
else
overstrike = 0;
}
if (ch == '\t')
{
/*
* Expand a tab into spaces.
*/
switch (bs_mode)
{
case BS_CONTROL:
goto do_control_char;