1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Michael Rendell of the Memorial University of Newfoundland.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <sys/capsicum.h>
36
37 #include <capsicum_helpers.h>
38 #include <err.h>
39 #include <errno.h>
40 #include <locale.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <termios.h>
45 #include <unistd.h>
46 #include <wchar.h>
47 #include <wctype.h>
48
49 #define BS '\b' /* backspace */
50 #define TAB '\t' /* tab */
51 #define SPACE ' ' /* space */
52 #define NL '\n' /* newline */
53 #define CR '\r' /* carriage return */
54 #define ESC '\033' /* escape */
55 #define SI '\017' /* shift in to normal character set */
56 #define SO '\016' /* shift out to alternate character set */
57 #define VT '\013' /* vertical tab (aka reverse line feed) */
58 #define RLF '7' /* ESC-7 reverse line feed */
59 #define RHLF '8' /* ESC-8 reverse half-line feed */
60 #define FHLF '9' /* ESC-9 forward half-line feed */
61
62 /* build up at least this many lines before flushing them out */
63 #define BUFFER_MARGIN 32
64
65 typedef char CSET;
66
67 typedef struct char_str {
68 #define CS_NORMAL 1
69 #define CS_ALTERNATE 2
70 short c_column; /* column character is in */
71 CSET c_set; /* character set (currently only 2) */
72 wchar_t c_char; /* character in question */
73 int c_width; /* character width */
74 } CHAR;
75
76 typedef struct line_str LINE;
77 struct line_str {
78 CHAR *l_line; /* characters on the line */
79 LINE *l_prev; /* previous line */
80 LINE *l_next; /* next line */
81 int l_lsize; /* allocated sizeof l_line */
82 int l_line_len; /* strlen(l_line) */
83 int l_needs_sort; /* set if chars went in out of order */
84 int l_max_col; /* max column in the line */
85 };
86
87 static void addto_lineno(int *, int);
88 static LINE *alloc_line(void);
89 static void dowarn(int);
90 static void flush_line(LINE *);
91 static void flush_lines(int);
92 static void flush_blanks(void);
93 static void free_line(LINE *);
94 static void usage(void);
95
96 static CSET last_set; /* char_set of last char printed */
97 static LINE *lines;
98 static int compress_spaces; /* if doing space -> tab conversion */
99 static int fine; /* if `fine' resolution (half lines) */
100 static int max_bufd_lines; /* max # of half lines to keep in memory */
101 static int nblank_lines; /* # blanks after last flushed line */
102 static int no_backspaces; /* if not to output any backspaces */
103 static int pass_unknown_seqs; /* pass unknown control sequences */
104
105 #define PUTC(ch) \
106 do { \
107 if (putwchar(ch) == WEOF) \
108 errx(1, "write error"); \
109 } while (0)
110
111 int
main(int argc,char ** argv)112 main(int argc, char **argv)
113 {
114 wint_t ch;
115 CHAR *c;
116 CSET cur_set; /* current character set */
117 LINE *l; /* current line */
118 int extra_lines; /* # of lines above first line */
119 int cur_col; /* current column */
120 int cur_line; /* line number of current position */
121 int max_line; /* max value of cur_line */
122 int this_line; /* line l points to */
123 int nflushd_lines; /* number of lines that were flushed */
124 int adjust, opt, warned, width;
125 const char *errstr;
126
127 (void)setlocale(LC_CTYPE, "");
128
129 if (caph_limit_stdio() == -1)
130 err(1, "unable to limit stdio");
131
132 if (caph_enter() < 0)
133 err(1, "unable to enter capability mode");
134
135 max_bufd_lines = 256;
136 compress_spaces = 1; /* compress spaces into tabs */
137 while ((opt = getopt(argc, argv, "bfhl:px")) != -1)
138 switch (opt) {
139 case 'b': /* do not output backspaces */
140 no_backspaces = 1;
141 break;
142 case 'f': /* allow half forward line feeds */
143 fine = 1;
144 break;
145 case 'h': /* compress spaces into tabs */
146 compress_spaces = 1;
147 break;
148 case 'l': /* buffered line count */
149 max_bufd_lines = strtonum(optarg, 1,
150 (INT_MAX - BUFFER_MARGIN) / 2, &errstr) * 2;
151 if (errstr != NULL)
152 errx(1, "bad -l argument, %s: %s", errstr,
153 optarg);
154 break;
155 case 'p': /* pass unknown control sequences */
156 pass_unknown_seqs = 1;
157 break;
158 case 'x': /* do not compress spaces into tabs */
159 compress_spaces = 0;
160 break;
161 case '?':
162 default:
163 usage();
164 }
165
166 if (optind != argc)
167 usage();
168
169 adjust = cur_col = extra_lines = warned = 0;
170 cur_line = max_line = nflushd_lines = this_line = 0;
171 cur_set = last_set = CS_NORMAL;
172 lines = l = alloc_line();
173
174 while ((ch = getwchar()) != WEOF) {
175 if (!iswgraph(ch)) {
176 switch (ch) {
177 case BS: /* can't go back further */
178 if (cur_col == 0)
179 continue;
180 --cur_col;
181 continue;
182 case CR:
183 cur_col = 0;
184 continue;
185 case ESC: /* just ignore EOF */
186 switch(getwchar()) {
187 /*
188 * In the input stream, accept both the
189 * XPG5 sequences ESC-digit and the
190 * traditional BSD sequences ESC-ctrl.
191 */
192 case '\007':
193 /* FALLTHROUGH */
194 case RLF:
195 addto_lineno(&cur_line, -2);
196 break;
197 case '\010':
198 /* FALLTHROUGH */
199 case RHLF:
200 addto_lineno(&cur_line, -1);
201 break;
202 case '\011':
203 /* FALLTHROUGH */
204 case FHLF:
205 addto_lineno(&cur_line, 1);
206 if (cur_line > max_line)
207 max_line = cur_line;
208 }
209 continue;
210 case NL:
211 addto_lineno(&cur_line, 2);
212 if (cur_line > max_line)
213 max_line = cur_line;
214 cur_col = 0;
215 continue;
216 case SPACE:
217 ++cur_col;
218 continue;
219 case SI:
220 cur_set = CS_NORMAL;
221 continue;
222 case SO:
223 cur_set = CS_ALTERNATE;
224 continue;
225 case TAB: /* adjust column */
226 cur_col |= 7;
227 ++cur_col;
228 continue;
229 case VT:
230 addto_lineno(&cur_line, -2);
231 continue;
232 }
233 if (iswspace(ch)) {
234 if ((width = wcwidth(ch)) > 0)
235 cur_col += width;
236 continue;
237 }
238 if (!pass_unknown_seqs)
239 continue;
240 }
241
242 /* Must stuff ch in a line - are we at the right one? */
243 if (cur_line + adjust != this_line) {
244 LINE *lnew;
245
246 /* round up to next line */
247 adjust = !fine && (cur_line & 1);
248
249 if (cur_line + adjust < this_line) {
250 while (cur_line + adjust < this_line &&
251 l->l_prev != NULL) {
252 l = l->l_prev;
253 this_line--;
254 }
255 if (cur_line + adjust < this_line) {
256 if (nflushd_lines == 0) {
257 /*
258 * Allow backup past first
259 * line if nothing has been
260 * flushed yet.
261 */
262 while (cur_line + adjust
263 < this_line) {
264 lnew = alloc_line();
265 l->l_prev = lnew;
266 lnew->l_next = l;
267 l = lines = lnew;
268 extra_lines++;
269 this_line--;
270 }
271 } else {
272 if (!warned++)
273 dowarn(cur_line);
274 cur_line = this_line - adjust;
275 }
276 }
277 } else {
278 /* may need to allocate here */
279 while (cur_line + adjust > this_line) {
280 if (l->l_next == NULL) {
281 l->l_next = alloc_line();
282 l->l_next->l_prev = l;
283 }
284 l = l->l_next;
285 this_line++;
286 }
287 }
288 if (this_line > nflushd_lines &&
289 this_line - nflushd_lines >=
290 max_bufd_lines + BUFFER_MARGIN) {
291 if (extra_lines) {
292 flush_lines(extra_lines);
293 extra_lines = 0;
294 }
295 flush_lines(this_line - nflushd_lines -
296 max_bufd_lines);
297 nflushd_lines = this_line - max_bufd_lines;
298 }
299 }
300 /* grow line's buffer? */
301 if (l->l_line_len + 1 >= l->l_lsize) {
302 int need;
303
304 need = l->l_lsize ? l->l_lsize * 2 : 90;
305 if ((l->l_line = realloc(l->l_line,
306 (unsigned)need * sizeof(CHAR))) == NULL)
307 err(1, NULL);
308 l->l_lsize = need;
309 }
310 c = &l->l_line[l->l_line_len++];
311 c->c_char = ch;
312 c->c_set = cur_set;
313 c->c_column = cur_col;
314 c->c_width = wcwidth(ch);
315 /*
316 * If things are put in out of order, they will need sorting
317 * when it is flushed.
318 */
319 if (cur_col < l->l_max_col)
320 l->l_needs_sort = 1;
321 else
322 l->l_max_col = cur_col;
323 if (c->c_width > 0)
324 cur_col += c->c_width;
325 }
326 if (ferror(stdin))
327 err(1, NULL);
328 if (extra_lines) {
329 /*
330 * Extra lines only exist if no lines have been flushed
331 * yet. This means that 'lines' must point to line zero
332 * after we flush the extra lines.
333 */
334 flush_lines(extra_lines);
335 l = lines;
336 this_line = 0;
337 }
338
339 /* goto the last line that had a character on it */
340 for (; l->l_next; l = l->l_next)
341 this_line++;
342 flush_lines(this_line - nflushd_lines + 1);
343
344 /* make sure we leave things in a sane state */
345 if (last_set != CS_NORMAL)
346 PUTC(SI);
347
348 /* flush out the last few blank lines */
349 if (max_line >= this_line)
350 nblank_lines = max_line - this_line + (max_line & 1);
351 if (nblank_lines == 0)
352 /* end with a newline even if the source doesn't */
353 nblank_lines = 2;
354 flush_blanks();
355 exit(0);
356 }
357
358 /*
359 * Prints the first 'nflush' lines. Printed lines are freed.
360 * After this function returns, 'lines' points to the first
361 * of the remaining lines, and 'nblank_lines' will have the
362 * number of half line feeds between the final flushed line
363 * and the first remaining line.
364 */
365 static void
flush_lines(int nflush)366 flush_lines(int nflush)
367 {
368 LINE *l;
369
370 while (--nflush >= 0) {
371 l = lines;
372 lines = l->l_next;
373 if (l->l_line) {
374 flush_blanks();
375 flush_line(l);
376 free(l->l_line);
377 }
378 if (l->l_next)
379 nblank_lines++;
380 free_line(l);
381 }
382 if (lines)
383 lines->l_prev = NULL;
384 }
385
386 /*
387 * Print a number of newline/half newlines.
388 * nblank_lines is the number of half line feeds.
389 */
390 static void
flush_blanks(void)391 flush_blanks(void)
392 {
393 int half, i, nb;
394
395 half = 0;
396 nb = nblank_lines;
397 if (nb & 1) {
398 if (fine)
399 half = 1;
400 else
401 nb++;
402 }
403 nb /= 2;
404 for (i = nb; --i >= 0;)
405 PUTC('\n');
406 if (half) {
407 PUTC(ESC);
408 PUTC(FHLF);
409 if (!nb)
410 PUTC('\r');
411 }
412 nblank_lines = 0;
413 }
414
415 /*
416 * Write a line to stdout taking care of space to tab conversion (-h flag)
417 * and character set shifts.
418 */
419 static void
flush_line(LINE * l)420 flush_line(LINE *l)
421 {
422 CHAR *c, *endc;
423 int i, j, nchars, last_col, save, this_col, tot;
424
425 last_col = 0;
426 nchars = l->l_line_len;
427
428 if (l->l_needs_sort) {
429 static CHAR *sorted;
430 static int count_size, *count, sorted_size;
431
432 /*
433 * Do an O(n) sort on l->l_line by column being careful to
434 * preserve the order of characters in the same column.
435 */
436 if (l->l_lsize > sorted_size) {
437 sorted_size = l->l_lsize;
438 if ((sorted = realloc(sorted,
439 (unsigned)sizeof(CHAR) * sorted_size)) == NULL)
440 err(1, NULL);
441 }
442 if (l->l_max_col >= count_size) {
443 count_size = l->l_max_col + 1;
444 if ((count = realloc(count,
445 (unsigned)sizeof(int) * count_size)) == NULL)
446 err(1, NULL);
447 }
448 memset(count, 0, sizeof(int) * l->l_max_col + 1);
449 for (i = nchars, c = l->l_line; --i >= 0; c++)
450 count[c->c_column]++;
451
452 /*
453 * calculate running total (shifted down by 1) to use as
454 * indices into new line.
455 */
456 for (tot = 0, i = 0; i <= l->l_max_col; i++) {
457 save = count[i];
458 count[i] = tot;
459 tot += save;
460 }
461
462 for (i = nchars, c = l->l_line; --i >= 0; c++)
463 sorted[count[c->c_column]++] = *c;
464 c = sorted;
465 } else
466 c = l->l_line;
467 while (nchars > 0) {
468 this_col = c->c_column;
469 endc = c;
470 do {
471 ++endc;
472 } while (--nchars > 0 && this_col == endc->c_column);
473
474 /* if -b only print last character */
475 if (no_backspaces) {
476 c = endc - 1;
477 if (nchars > 0 &&
478 this_col + c->c_width > endc->c_column)
479 continue;
480 }
481
482 if (this_col > last_col) {
483 int nspace = this_col - last_col;
484
485 if (compress_spaces && nspace > 1) {
486 while (1) {
487 int tab_col, tab_size;
488
489 tab_col = (last_col + 8) & ~7;
490 if (tab_col > this_col)
491 break;
492 tab_size = tab_col - last_col;
493 if (tab_size == 1)
494 PUTC(' ');
495 else
496 PUTC('\t');
497 nspace -= tab_size;
498 last_col = tab_col;
499 }
500 }
501 while (--nspace >= 0)
502 PUTC(' ');
503 last_col = this_col;
504 }
505
506 for (;;) {
507 if (c->c_set != last_set) {
508 switch (c->c_set) {
509 case CS_NORMAL:
510 PUTC(SI);
511 break;
512 case CS_ALTERNATE:
513 PUTC(SO);
514 }
515 last_set = c->c_set;
516 }
517 PUTC(c->c_char);
518 if ((c + 1) < endc)
519 for (j = 0; j < c->c_width; j++)
520 PUTC('\b');
521 if (++c >= endc)
522 break;
523 }
524 last_col += (c - 1)->c_width;
525 }
526 }
527
528 /*
529 * Increment or decrement a line number, checking for overflow.
530 * Stop one below INT_MAX such that the adjust variable is safe.
531 */
532 void
addto_lineno(int * lno,int offset)533 addto_lineno(int *lno, int offset)
534 {
535 if (offset > 0) {
536 if (*lno >= INT_MAX - offset)
537 errx(1, "too many lines");
538 } else {
539 if (*lno < INT_MIN - offset)
540 errx(1, "too many reverse line feeds");
541 }
542 *lno += offset;
543 }
544
545 #define NALLOC 64
546
547 static LINE *line_freelist;
548
549 static LINE *
alloc_line(void)550 alloc_line(void)
551 {
552 LINE *l;
553 int i;
554
555 if (!line_freelist) {
556 if ((l = realloc(NULL, sizeof(LINE) * NALLOC)) == NULL)
557 err(1, NULL);
558 line_freelist = l;
559 for (i = 1; i < NALLOC; i++, l++)
560 l->l_next = l + 1;
561 l->l_next = NULL;
562 }
563 l = line_freelist;
564 line_freelist = l->l_next;
565
566 memset(l, 0, sizeof(LINE));
567 return (l);
568 }
569
570 static void
free_line(LINE * l)571 free_line(LINE *l)
572 {
573
574 l->l_next = line_freelist;
575 line_freelist = l;
576 }
577
578 static void
usage(void)579 usage(void)
580 {
581
582 (void)fprintf(stderr, "usage: col [-bfhpx] [-l nline]\n");
583 exit(1);
584 }
585
586 static void
dowarn(int line)587 dowarn(int line)
588 {
589
590 warnx("warning: can't back up %s",
591 line < 0 ? "past first line" : "-- line already flushed");
592 }
593