xref: /freebsd/usr.bin/col/col.c (revision bd1da0a002e9a43cfb5220835c7a42804d90dc56)
1 /*-
2  * Copyright (c) 1990, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Michael Rendell of the Memorial University of Newfoundland.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 static const char copyright[] =
35 "@(#) Copyright (c) 1990, 1993, 1994\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif
38 
39 #if 0
40 #ifndef lint
41 static char sccsid[] = "@(#)col.c	8.5 (Berkeley) 5/4/95";
42 #endif
43 #endif
44 
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
47 
48 #include <sys/capsicum.h>
49 
50 #include <err.h>
51 #include <errno.h>
52 #include <locale.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <termios.h>
57 #include <unistd.h>
58 #include <wchar.h>
59 #include <wctype.h>
60 
61 #define	BS	'\b'		/* backspace */
62 #define	TAB	'\t'		/* tab */
63 #define	SPACE	' '		/* space */
64 #define	NL	'\n'		/* newline */
65 #define	CR	'\r'		/* carriage return */
66 #define	ESC	'\033'		/* escape */
67 #define	SI	'\017'		/* shift in to normal character set */
68 #define	SO	'\016'		/* shift out to alternate character set */
69 #define	VT	'\013'		/* vertical tab (aka reverse line feed) */
70 #define	RLF	'7'		/* ESC-7 reverse line feed */
71 #define	RHLF	'8'		/* ESC-8 reverse half-line feed */
72 #define	FHLF	'9'		/* ESC-9 forward half-line feed */
73 
74 /* build up at least this many lines before flushing them out */
75 #define	BUFFER_MARGIN		32
76 
77 typedef char CSET;
78 
79 typedef struct char_str {
80 #define	CS_NORMAL	1
81 #define	CS_ALTERNATE	2
82 	short		c_column;	/* column character is in */
83 	CSET		c_set;		/* character set (currently only 2) */
84 	wchar_t		c_char;		/* character in question */
85 	int		c_width;	/* character width */
86 } CHAR;
87 
88 typedef struct line_str LINE;
89 struct line_str {
90 	CHAR	*l_line;		/* characters on the line */
91 	LINE	*l_prev;		/* previous line */
92 	LINE	*l_next;		/* next line */
93 	int	l_lsize;		/* allocated sizeof l_line */
94 	int	l_line_len;		/* strlen(l_line) */
95 	int	l_needs_sort;		/* set if chars went in out of order */
96 	int	l_max_col;		/* max column in the line */
97 };
98 
99 static LINE   *alloc_line(void);
100 static void	dowarn(int);
101 static void	flush_line(LINE *);
102 static void	flush_lines(int);
103 static void	flush_blanks(void);
104 static void	free_line(LINE *);
105 static void	usage(void);
106 
107 static CSET	last_set;		/* char_set of last char printed */
108 static LINE    *lines;
109 static int	compress_spaces;	/* if doing space -> tab conversion */
110 static int	fine;			/* if `fine' resolution (half lines) */
111 static int	max_bufd_lines;		/* max # lines to keep in memory */
112 static int	nblank_lines;		/* # blanks after last flushed line */
113 static int	no_backspaces;		/* if not to output any backspaces */
114 static int	pass_unknown_seqs;	/* pass unknown control sequences */
115 
116 #define	PUTC(ch) \
117 	do {					\
118 		if (putwchar(ch) == WEOF)	\
119 			errx(1, "write error");	\
120 	} while (0)
121 
122 int
123 main(int argc, char **argv)
124 {
125 	wint_t ch;
126 	CHAR *c;
127 	CSET cur_set;			/* current character set */
128 	LINE *l;			/* current line */
129 	int extra_lines;		/* # of lines above first line */
130 	int cur_col;			/* current column */
131 	int cur_line;			/* line number of current position */
132 	int max_line;			/* max value of cur_line */
133 	int this_line;			/* line l points to */
134 	int nflushd_lines;		/* number of lines that were flushed */
135 	int adjust, opt, warned, width;
136 	cap_rights_t rights;
137 	unsigned long cmd;
138 
139 	(void)setlocale(LC_CTYPE, "");
140 
141 	cap_rights_init(&rights, CAP_FSTAT, CAP_READ);
142 	if (cap_rights_limit(STDIN_FILENO, &rights) < 0 && errno != ENOSYS)
143 		err(1, "unable to limit rights for stdin");
144 	cap_rights_init(&rights, CAP_FSTAT, CAP_WRITE, CAP_IOCTL);
145 	if (cap_rights_limit(STDOUT_FILENO, &rights) < 0 && errno != ENOSYS)
146 		err(1, "unable to limit rights for stdout");
147 	cmd = TIOCGETA; /* required by isatty(3) in printf(3) */
148 	if (cap_ioctls_limit(STDOUT_FILENO, &cmd, 1) < 0 && errno != ENOSYS)
149 		err(1, "unable to limit ioctls for stdout");
150 
151 	if (cap_enter() < 0 && errno != ENOSYS)
152 		err(1, "unable to enter capability mode");
153 
154 	max_bufd_lines = 128;
155 	compress_spaces = 1;		/* compress spaces into tabs */
156 	while ((opt = getopt(argc, argv, "bfhl:px")) != -1)
157 		switch (opt) {
158 		case 'b':		/* do not output backspaces */
159 			no_backspaces = 1;
160 			break;
161 		case 'f':		/* allow half forward line feeds */
162 			fine = 1;
163 			break;
164 		case 'h':		/* compress spaces into tabs */
165 			compress_spaces = 1;
166 			break;
167 		case 'l':		/* buffered line count */
168 			if ((max_bufd_lines = atoi(optarg)) <= 0)
169 				errx(1, "bad -l argument %s", optarg);
170 			break;
171 		case 'p':		/* pass unknown control sequences */
172 			pass_unknown_seqs = 1;
173 			break;
174 		case 'x':		/* do not compress spaces into tabs */
175 			compress_spaces = 0;
176 			break;
177 		case '?':
178 		default:
179 			usage();
180 		}
181 
182 	if (optind != argc)
183 		usage();
184 
185 	/* this value is in half lines */
186 	max_bufd_lines *= 2;
187 
188 	adjust = cur_col = extra_lines = warned = 0;
189 	cur_line = max_line = nflushd_lines = this_line = 0;
190 	cur_set = last_set = CS_NORMAL;
191 	lines = l = alloc_line();
192 
193 	while ((ch = getwchar()) != WEOF) {
194 		if (!iswgraph(ch)) {
195 			switch (ch) {
196 			case BS:		/* can't go back further */
197 				if (cur_col == 0)
198 					continue;
199 				--cur_col;
200 				continue;
201 			case CR:
202 				cur_col = 0;
203 				continue;
204 			case ESC:		/* just ignore EOF */
205 				switch(getwchar()) {
206 				case RLF:
207 					cur_line -= 2;
208 					break;
209 				case RHLF:
210 					cur_line--;
211 					break;
212 				case FHLF:
213 					cur_line++;
214 					if (cur_line > max_line)
215 						max_line = cur_line;
216 				}
217 				continue;
218 			case NL:
219 				cur_line += 2;
220 				if (cur_line > max_line)
221 					max_line = cur_line;
222 				cur_col = 0;
223 				continue;
224 			case SPACE:
225 				++cur_col;
226 				continue;
227 			case SI:
228 				cur_set = CS_NORMAL;
229 				continue;
230 			case SO:
231 				cur_set = CS_ALTERNATE;
232 				continue;
233 			case TAB:		/* adjust column */
234 				cur_col |= 7;
235 				++cur_col;
236 				continue;
237 			case VT:
238 				cur_line -= 2;
239 				continue;
240 			}
241 			if (iswspace(ch)) {
242 				if ((width = wcwidth(ch)) > 0)
243 					cur_col += width;
244 				continue;
245 			}
246 			if (!pass_unknown_seqs)
247 				continue;
248 		}
249 
250 		/* Must stuff ch in a line - are we at the right one? */
251 		if (cur_line != this_line - adjust) {
252 			LINE *lnew;
253 			int nmove;
254 
255 			adjust = 0;
256 			nmove = cur_line - this_line;
257 			if (!fine) {
258 				/* round up to next line */
259 				if (cur_line & 1) {
260 					adjust = 1;
261 					nmove++;
262 				}
263 			}
264 			if (nmove < 0) {
265 				for (; nmove < 0 && l->l_prev; nmove++)
266 					l = l->l_prev;
267 				if (nmove) {
268 					if (nflushd_lines == 0) {
269 						/*
270 						 * Allow backup past first
271 						 * line if nothing has been
272 						 * flushed yet.
273 						 */
274 						for (; nmove < 0; nmove++) {
275 							lnew = alloc_line();
276 							l->l_prev = lnew;
277 							lnew->l_next = l;
278 							l = lines = lnew;
279 							extra_lines++;
280 						}
281 					} else {
282 						if (!warned++)
283 							dowarn(cur_line);
284 						cur_line -= nmove;
285 					}
286 				}
287 			} else {
288 				/* may need to allocate here */
289 				for (; nmove > 0 && l->l_next; nmove--)
290 					l = l->l_next;
291 				for (; nmove > 0; nmove--) {
292 					lnew = alloc_line();
293 					lnew->l_prev = l;
294 					l->l_next = lnew;
295 					l = lnew;
296 				}
297 			}
298 			this_line = cur_line + adjust;
299 			nmove = this_line - nflushd_lines;
300 			if (nmove >= max_bufd_lines + BUFFER_MARGIN) {
301 				nflushd_lines += nmove - max_bufd_lines;
302 				flush_lines(nmove - max_bufd_lines);
303 			}
304 		}
305 		/* grow line's buffer? */
306 		if (l->l_line_len + 1 >= l->l_lsize) {
307 			int need;
308 
309 			need = l->l_lsize ? l->l_lsize * 2 : 90;
310 			if ((l->l_line = realloc(l->l_line,
311 			    (unsigned)need * sizeof(CHAR))) == NULL)
312 				err(1, NULL);
313 			l->l_lsize = need;
314 		}
315 		c = &l->l_line[l->l_line_len++];
316 		c->c_char = ch;
317 		c->c_set = cur_set;
318 		c->c_column = cur_col;
319 		c->c_width = wcwidth(ch);
320 		/*
321 		 * If things are put in out of order, they will need sorting
322 		 * when it is flushed.
323 		 */
324 		if (cur_col < l->l_max_col)
325 			l->l_needs_sort = 1;
326 		else
327 			l->l_max_col = cur_col;
328 		if (c->c_width > 0)
329 			cur_col += c->c_width;
330 	}
331 	if (ferror(stdin))
332 		err(1, NULL);
333 	if (max_line == 0)
334 		exit(0);	/* no lines, so just exit */
335 
336 	/* goto the last line that had a character on it */
337 	for (; l->l_next; l = l->l_next)
338 		this_line++;
339 	flush_lines(this_line - nflushd_lines + extra_lines + 1);
340 
341 	/* make sure we leave things in a sane state */
342 	if (last_set != CS_NORMAL)
343 		PUTC(SI);
344 
345 	/* flush out the last few blank lines */
346 	nblank_lines = max_line - this_line;
347 	if (max_line & 1)
348 		nblank_lines++;
349 	else if (!nblank_lines)
350 		/* missing a \n on the last line? */
351 		nblank_lines = 2;
352 	flush_blanks();
353 	exit(0);
354 }
355 
356 static void
357 flush_lines(int nflush)
358 {
359 	LINE *l;
360 
361 	while (--nflush >= 0) {
362 		l = lines;
363 		lines = l->l_next;
364 		if (l->l_line) {
365 			flush_blanks();
366 			flush_line(l);
367 		}
368 		nblank_lines++;
369 		if (l->l_line)
370 			(void)free(l->l_line);
371 		free_line(l);
372 	}
373 	if (lines)
374 		lines->l_prev = NULL;
375 }
376 
377 /*
378  * Print a number of newline/half newlines.  If fine flag is set, nblank_lines
379  * is the number of half line feeds, otherwise it is the number of whole line
380  * feeds.
381  */
382 static void
383 flush_blanks(void)
384 {
385 	int half, i, nb;
386 
387 	half = 0;
388 	nb = nblank_lines;
389 	if (nb & 1) {
390 		if (fine)
391 			half = 1;
392 		else
393 			nb++;
394 	}
395 	nb /= 2;
396 	for (i = nb; --i >= 0;)
397 		PUTC('\n');
398 	if (half) {
399 		PUTC(ESC);
400 		PUTC(FHLF);
401 		if (!nb)
402 			PUTC('\r');
403 	}
404 	nblank_lines = 0;
405 }
406 
407 /*
408  * Write a line to stdout taking care of space to tab conversion (-h flag)
409  * and character set shifts.
410  */
411 static void
412 flush_line(LINE *l)
413 {
414 	CHAR *c, *endc;
415 	int i, j, nchars, last_col, save, this_col, tot;
416 
417 	last_col = 0;
418 	nchars = l->l_line_len;
419 
420 	if (l->l_needs_sort) {
421 		static CHAR *sorted;
422 		static int count_size, *count, sorted_size;
423 
424 		/*
425 		 * Do an O(n) sort on l->l_line by column being careful to
426 		 * preserve the order of characters in the same column.
427 		 */
428 		if (l->l_lsize > sorted_size) {
429 			sorted_size = l->l_lsize;
430 			if ((sorted = realloc(sorted,
431 			    (unsigned)sizeof(CHAR) * sorted_size)) == NULL)
432 				err(1, NULL);
433 		}
434 		if (l->l_max_col >= count_size) {
435 			count_size = l->l_max_col + 1;
436 			if ((count = realloc(count,
437 			    (unsigned)sizeof(int) * count_size)) == NULL)
438 				err(1, NULL);
439 		}
440 		memset(count, 0, sizeof(int) * l->l_max_col + 1);
441 		for (i = nchars, c = l->l_line; --i >= 0; c++)
442 			count[c->c_column]++;
443 
444 		/*
445 		 * calculate running total (shifted down by 1) to use as
446 		 * indices into new line.
447 		 */
448 		for (tot = 0, i = 0; i <= l->l_max_col; i++) {
449 			save = count[i];
450 			count[i] = tot;
451 			tot += save;
452 		}
453 
454 		for (i = nchars, c = l->l_line; --i >= 0; c++)
455 			sorted[count[c->c_column]++] = *c;
456 		c = sorted;
457 	} else
458 		c = l->l_line;
459 	while (nchars > 0) {
460 		this_col = c->c_column;
461 		endc = c;
462 		do {
463 			++endc;
464 		} while (--nchars > 0 && this_col == endc->c_column);
465 
466 		/* if -b only print last character */
467 		if (no_backspaces) {
468 			c = endc - 1;
469 			if (nchars > 0 &&
470 			    this_col + c->c_width > endc->c_column)
471 				continue;
472 		}
473 
474 		if (this_col > last_col) {
475 			int nspace = this_col - last_col;
476 
477 			if (compress_spaces && nspace > 1) {
478 				while (1) {
479 					int tab_col, tab_size;
480 
481 					tab_col = (last_col + 8) & ~7;
482 					if (tab_col > this_col)
483 						break;
484 					tab_size = tab_col - last_col;
485 					if (tab_size == 1)
486 						PUTC(' ');
487 					else
488 						PUTC('\t');
489 					nspace -= tab_size;
490 					last_col = tab_col;
491 				}
492 			}
493 			while (--nspace >= 0)
494 				PUTC(' ');
495 			last_col = this_col;
496 		}
497 
498 		for (;;) {
499 			if (c->c_set != last_set) {
500 				switch (c->c_set) {
501 				case CS_NORMAL:
502 					PUTC(SI);
503 					break;
504 				case CS_ALTERNATE:
505 					PUTC(SO);
506 				}
507 				last_set = c->c_set;
508 			}
509 			PUTC(c->c_char);
510 			if ((c + 1) < endc)
511 				for (j = 0; j < c->c_width; j++)
512 					PUTC('\b');
513 			if (++c >= endc)
514 				break;
515 		}
516 		last_col += (c - 1)->c_width;
517 	}
518 }
519 
520 #define	NALLOC 64
521 
522 static LINE *line_freelist;
523 
524 static LINE *
525 alloc_line(void)
526 {
527 	LINE *l;
528 	int i;
529 
530 	if (!line_freelist) {
531 		if ((l = realloc(NULL, sizeof(LINE) * NALLOC)) == NULL)
532 			err(1, NULL);
533 		line_freelist = l;
534 		for (i = 1; i < NALLOC; i++, l++)
535 			l->l_next = l + 1;
536 		l->l_next = NULL;
537 	}
538 	l = line_freelist;
539 	line_freelist = l->l_next;
540 
541 	memset(l, 0, sizeof(LINE));
542 	return (l);
543 }
544 
545 static void
546 free_line(LINE *l)
547 {
548 
549 	l->l_next = line_freelist;
550 	line_freelist = l;
551 }
552 
553 static void
554 usage(void)
555 {
556 
557 	(void)fprintf(stderr, "usage: col [-bfhpx] [-l nline]\n");
558 	exit(1);
559 }
560 
561 static void
562 dowarn(int line)
563 {
564 
565 	warnx("warning: can't back up %s",
566 		line < 0 ? "past first line" : "-- line already flushed");
567 }
568