xref: /freebsd/usr.bin/col/col.c (revision 4232f826683298e85d469c0ef17259cecd13b2c7)
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 void	addto_lineno(int *, int);
100 static LINE   *alloc_line(void);
101 static void	dowarn(int);
102 static void	flush_line(LINE *);
103 static void	flush_lines(int);
104 static void	flush_blanks(void);
105 static void	free_line(LINE *);
106 static void	usage(void);
107 
108 static CSET	last_set;		/* char_set of last char printed */
109 static LINE    *lines;
110 static int	compress_spaces;	/* if doing space -> tab conversion */
111 static int	fine;			/* if `fine' resolution (half lines) */
112 static int	max_bufd_lines;		/* max # of half lines to keep in memory */
113 static int	nblank_lines;		/* # blanks after last flushed line */
114 static int	no_backspaces;		/* if not to output any backspaces */
115 static int	pass_unknown_seqs;	/* pass unknown control sequences */
116 
117 #define	PUTC(ch) \
118 	do {					\
119 		if (putwchar(ch) == WEOF)	\
120 			errx(1, "write error");	\
121 	} while (0)
122 
123 int
124 main(int argc, char **argv)
125 {
126 	wint_t ch;
127 	CHAR *c;
128 	CSET cur_set;			/* current character set */
129 	LINE *l;			/* current line */
130 	int extra_lines;		/* # of lines above first line */
131 	int cur_col;			/* current column */
132 	int cur_line;			/* line number of current position */
133 	int max_line;			/* max value of cur_line */
134 	int this_line;			/* line l points to */
135 	int nflushd_lines;		/* number of lines that were flushed */
136 	int adjust, opt, warned, width;
137 	const char *errstr;
138 	cap_rights_t rights;
139 	unsigned long cmd;
140 
141 	(void)setlocale(LC_CTYPE, "");
142 
143 	cap_rights_init(&rights, CAP_FSTAT, CAP_READ);
144 	if (cap_rights_limit(STDIN_FILENO, &rights) < 0 && errno != ENOSYS)
145 		err(1, "unable to limit rights for stdin");
146 	cap_rights_init(&rights, CAP_FSTAT, CAP_WRITE, CAP_IOCTL);
147 	if (cap_rights_limit(STDOUT_FILENO, &rights) < 0 && errno != ENOSYS)
148 		err(1, "unable to limit rights for stdout");
149 	cmd = TIOCGETA; /* required by isatty(3) in printf(3) */
150 	if (cap_ioctls_limit(STDOUT_FILENO, &cmd, 1) < 0 && errno != ENOSYS)
151 		err(1, "unable to limit ioctls for stdout");
152 
153 	if (cap_enter() < 0 && errno != ENOSYS)
154 		err(1, "unable to enter capability mode");
155 
156 	max_bufd_lines = 256;
157 	compress_spaces = 1;		/* compress spaces into tabs */
158 	while ((opt = getopt(argc, argv, "bfhl:px")) != -1)
159 		switch (opt) {
160 		case 'b':		/* do not output backspaces */
161 			no_backspaces = 1;
162 			break;
163 		case 'f':		/* allow half forward line feeds */
164 			fine = 1;
165 			break;
166 		case 'h':		/* compress spaces into tabs */
167 			compress_spaces = 1;
168 			break;
169 		case 'l':		/* buffered line count */
170 			max_bufd_lines = strtonum(optarg, 1,
171 			    (INT_MAX - BUFFER_MARGIN) / 2, &errstr) * 2;
172 			if (errstr != NULL)
173 				errx(1, "bad -l argument, %s: %s", errstr,
174 					optarg);
175 			break;
176 		case 'p':		/* pass unknown control sequences */
177 			pass_unknown_seqs = 1;
178 			break;
179 		case 'x':		/* do not compress spaces into tabs */
180 			compress_spaces = 0;
181 			break;
182 		case '?':
183 		default:
184 			usage();
185 		}
186 
187 	if (optind != argc)
188 		usage();
189 
190 	adjust = cur_col = extra_lines = warned = 0;
191 	cur_line = max_line = nflushd_lines = this_line = 0;
192 	cur_set = last_set = CS_NORMAL;
193 	lines = l = alloc_line();
194 
195 	while ((ch = getwchar()) != WEOF) {
196 		if (!iswgraph(ch)) {
197 			switch (ch) {
198 			case BS:		/* can't go back further */
199 				if (cur_col == 0)
200 					continue;
201 				--cur_col;
202 				continue;
203 			case CR:
204 				cur_col = 0;
205 				continue;
206 			case ESC:		/* just ignore EOF */
207 				switch(getwchar()) {
208 				/*
209 				 * In the input stream, accept both the
210 				 * XPG5 sequences ESC-digit and the
211 				 * traditional BSD sequences ESC-ctrl.
212 				 */
213 				case '\007':
214 					/* FALLTHROUGH */
215 				case RLF:
216 					addto_lineno(&cur_line, -2);
217 					break;
218 				case '\010':
219 					/* FALLTHROUGH */
220 				case RHLF:
221 					addto_lineno(&cur_line, -1);
222 					break;
223 				case '\011':
224 					/* FALLTHROUGH */
225 				case FHLF:
226 					addto_lineno(&cur_line, 1);
227 					if (cur_line > max_line)
228 						max_line = cur_line;
229 				}
230 				continue;
231 			case NL:
232 				addto_lineno(&cur_line, 2);
233 				if (cur_line > max_line)
234 					max_line = cur_line;
235 				cur_col = 0;
236 				continue;
237 			case SPACE:
238 				++cur_col;
239 				continue;
240 			case SI:
241 				cur_set = CS_NORMAL;
242 				continue;
243 			case SO:
244 				cur_set = CS_ALTERNATE;
245 				continue;
246 			case TAB:		/* adjust column */
247 				cur_col |= 7;
248 				++cur_col;
249 				continue;
250 			case VT:
251 				addto_lineno(&cur_line, -2);
252 				continue;
253 			}
254 			if (iswspace(ch)) {
255 				if ((width = wcwidth(ch)) > 0)
256 					cur_col += width;
257 				continue;
258 			}
259 			if (!pass_unknown_seqs)
260 				continue;
261 		}
262 
263 		/* Must stuff ch in a line - are we at the right one? */
264 		if (cur_line + adjust != this_line) {
265 			LINE *lnew;
266 
267 			/* round up to next line */
268 			adjust = !fine && (cur_line & 1);
269 
270 			if (cur_line + adjust < this_line) {
271 				while (cur_line + adjust < this_line &&
272 				    l->l_prev != NULL) {
273 					l = l->l_prev;
274 					this_line--;
275 				}
276 				if (cur_line + adjust < this_line) {
277 					if (nflushd_lines == 0) {
278 						/*
279 						 * Allow backup past first
280 						 * line if nothing has been
281 						 * flushed yet.
282 						 */
283 						while (cur_line + adjust
284 						    < this_line) {
285 							lnew = alloc_line();
286 							l->l_prev = lnew;
287 							lnew->l_next = l;
288 							l = lines = lnew;
289 							extra_lines++;
290 							this_line--;
291 						}
292 					} else {
293 						if (!warned++)
294 							dowarn(cur_line);
295 						cur_line = this_line - adjust;
296 					}
297 				}
298 			} else {
299 				/* may need to allocate here */
300 				while (cur_line + adjust > this_line) {
301 					if (l->l_next == NULL) {
302 						l->l_next = alloc_line();
303 						l->l_next->l_prev = l;
304 					}
305 					l = l->l_next;
306 					this_line++;
307 				}
308 			}
309 			if (this_line > nflushd_lines &&
310 			    this_line - nflushd_lines >=
311 			    max_bufd_lines + BUFFER_MARGIN) {
312 				if (extra_lines) {
313 					flush_lines(extra_lines);
314 					extra_lines = 0;
315 				}
316 				flush_lines(this_line - nflushd_lines -
317 				    max_bufd_lines);
318 				nflushd_lines = this_line - max_bufd_lines;
319 			}
320 		}
321 		/* grow line's buffer? */
322 		if (l->l_line_len + 1 >= l->l_lsize) {
323 			int need;
324 
325 			need = l->l_lsize ? l->l_lsize * 2 : 90;
326 			if ((l->l_line = realloc(l->l_line,
327 			    (unsigned)need * sizeof(CHAR))) == NULL)
328 				err(1, NULL);
329 			l->l_lsize = need;
330 		}
331 		c = &l->l_line[l->l_line_len++];
332 		c->c_char = ch;
333 		c->c_set = cur_set;
334 		c->c_column = cur_col;
335 		c->c_width = wcwidth(ch);
336 		/*
337 		 * If things are put in out of order, they will need sorting
338 		 * when it is flushed.
339 		 */
340 		if (cur_col < l->l_max_col)
341 			l->l_needs_sort = 1;
342 		else
343 			l->l_max_col = cur_col;
344 		if (c->c_width > 0)
345 			cur_col += c->c_width;
346 	}
347 	if (ferror(stdin))
348 		err(1, NULL);
349 	if (extra_lines)
350 		flush_lines(extra_lines);
351 
352 	/* goto the last line that had a character on it */
353 	for (; l->l_next; l = l->l_next)
354 		this_line++;
355 	flush_lines(this_line - nflushd_lines + 1);
356 
357 	/* make sure we leave things in a sane state */
358 	if (last_set != CS_NORMAL)
359 		PUTC(SI);
360 
361 	/* flush out the last few blank lines */
362 	if (max_line > this_line)
363 		nblank_lines = max_line - this_line;
364 	if (max_line & 1)
365 		nblank_lines++;
366 	flush_blanks();
367 	exit(0);
368 }
369 
370 static void
371 flush_lines(int nflush)
372 {
373 	LINE *l;
374 
375 	while (--nflush >= 0) {
376 		l = lines;
377 		lines = l->l_next;
378 		if (l->l_line) {
379 			flush_blanks();
380 			flush_line(l);
381 		}
382 		if (l->l_line || l->l_next)
383 			nblank_lines++;
384 		if (l->l_line)
385 			(void)free(l->l_line);
386 		free_line(l);
387 	}
388 	if (lines)
389 		lines->l_prev = NULL;
390 }
391 
392 /*
393  * Print a number of newline/half newlines.  If fine flag is set, nblank_lines
394  * is the number of half line feeds, otherwise it is the number of whole line
395  * feeds.
396  */
397 static void
398 flush_blanks(void)
399 {
400 	int half, i, nb;
401 
402 	half = 0;
403 	nb = nblank_lines;
404 	if (nb & 1) {
405 		if (fine)
406 			half = 1;
407 		else
408 			nb++;
409 	}
410 	nb /= 2;
411 	for (i = nb; --i >= 0;)
412 		PUTC('\n');
413 	if (half) {
414 		PUTC(ESC);
415 		PUTC(FHLF);
416 		if (!nb)
417 			PUTC('\r');
418 	}
419 	nblank_lines = 0;
420 }
421 
422 /*
423  * Write a line to stdout taking care of space to tab conversion (-h flag)
424  * and character set shifts.
425  */
426 static void
427 flush_line(LINE *l)
428 {
429 	CHAR *c, *endc;
430 	int i, j, nchars, last_col, save, this_col, tot;
431 
432 	last_col = 0;
433 	nchars = l->l_line_len;
434 
435 	if (l->l_needs_sort) {
436 		static CHAR *sorted;
437 		static int count_size, *count, sorted_size;
438 
439 		/*
440 		 * Do an O(n) sort on l->l_line by column being careful to
441 		 * preserve the order of characters in the same column.
442 		 */
443 		if (l->l_lsize > sorted_size) {
444 			sorted_size = l->l_lsize;
445 			if ((sorted = realloc(sorted,
446 			    (unsigned)sizeof(CHAR) * sorted_size)) == NULL)
447 				err(1, NULL);
448 		}
449 		if (l->l_max_col >= count_size) {
450 			count_size = l->l_max_col + 1;
451 			if ((count = realloc(count,
452 			    (unsigned)sizeof(int) * count_size)) == NULL)
453 				err(1, NULL);
454 		}
455 		memset(count, 0, sizeof(int) * l->l_max_col + 1);
456 		for (i = nchars, c = l->l_line; --i >= 0; c++)
457 			count[c->c_column]++;
458 
459 		/*
460 		 * calculate running total (shifted down by 1) to use as
461 		 * indices into new line.
462 		 */
463 		for (tot = 0, i = 0; i <= l->l_max_col; i++) {
464 			save = count[i];
465 			count[i] = tot;
466 			tot += save;
467 		}
468 
469 		for (i = nchars, c = l->l_line; --i >= 0; c++)
470 			sorted[count[c->c_column]++] = *c;
471 		c = sorted;
472 	} else
473 		c = l->l_line;
474 	while (nchars > 0) {
475 		this_col = c->c_column;
476 		endc = c;
477 		do {
478 			++endc;
479 		} while (--nchars > 0 && this_col == endc->c_column);
480 
481 		/* if -b only print last character */
482 		if (no_backspaces) {
483 			c = endc - 1;
484 			if (nchars > 0 &&
485 			    this_col + c->c_width > endc->c_column)
486 				continue;
487 		}
488 
489 		if (this_col > last_col) {
490 			int nspace = this_col - last_col;
491 
492 			if (compress_spaces && nspace > 1) {
493 				while (1) {
494 					int tab_col, tab_size;
495 
496 					tab_col = (last_col + 8) & ~7;
497 					if (tab_col > this_col)
498 						break;
499 					tab_size = tab_col - last_col;
500 					if (tab_size == 1)
501 						PUTC(' ');
502 					else
503 						PUTC('\t');
504 					nspace -= tab_size;
505 					last_col = tab_col;
506 				}
507 			}
508 			while (--nspace >= 0)
509 				PUTC(' ');
510 			last_col = this_col;
511 		}
512 
513 		for (;;) {
514 			if (c->c_set != last_set) {
515 				switch (c->c_set) {
516 				case CS_NORMAL:
517 					PUTC(SI);
518 					break;
519 				case CS_ALTERNATE:
520 					PUTC(SO);
521 				}
522 				last_set = c->c_set;
523 			}
524 			PUTC(c->c_char);
525 			if ((c + 1) < endc)
526 				for (j = 0; j < c->c_width; j++)
527 					PUTC('\b');
528 			if (++c >= endc)
529 				break;
530 		}
531 		last_col += (c - 1)->c_width;
532 	}
533 }
534 
535 /*
536  * Increment or decrement a line number, checking for overflow.
537  * Stop one below INT_MAX such that the adjust variable is safe.
538  */
539 void
540 addto_lineno(int *lno, int offset)
541 {
542 	if (offset > 0) {
543 		if (*lno >= INT_MAX - offset)
544 			errx(1, "too many lines");
545 	} else {
546 		if (*lno < INT_MIN - offset)
547 			errx(1, "too many reverse line feeds");
548 	}
549 	*lno += offset;
550 }
551 
552 #define	NALLOC 64
553 
554 static LINE *line_freelist;
555 
556 static LINE *
557 alloc_line(void)
558 {
559 	LINE *l;
560 	int i;
561 
562 	if (!line_freelist) {
563 		if ((l = realloc(NULL, sizeof(LINE) * NALLOC)) == NULL)
564 			err(1, NULL);
565 		line_freelist = l;
566 		for (i = 1; i < NALLOC; i++, l++)
567 			l->l_next = l + 1;
568 		l->l_next = NULL;
569 	}
570 	l = line_freelist;
571 	line_freelist = l->l_next;
572 
573 	memset(l, 0, sizeof(LINE));
574 	return (l);
575 }
576 
577 static void
578 free_line(LINE *l)
579 {
580 
581 	l->l_next = line_freelist;
582 	line_freelist = l;
583 }
584 
585 static void
586 usage(void)
587 {
588 
589 	(void)fprintf(stderr, "usage: col [-bfhpx] [-l nline]\n");
590 	exit(1);
591 }
592 
593 static void
594 dowarn(int line)
595 {
596 
597 	warnx("warning: can't back up %s",
598 		line < 0 ? "past first line" : "-- line already flushed");
599 }
600