xref: /dragonfly/usr.bin/col/col.c (revision 030b3383)
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  * 3. 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  * @(#) Copyright (c) 1990, 1993, 1994 The Regents of the University of California.  All rights reserved.
33  * @(#)col.c	8.5 (Berkeley) 5/4/95
34  * $FreeBSD: head/usr.bin/col/col.c 282722 2015-05-10 11:41:38Z bapt $
35  */
36 
37 #include <err.h>
38 #include <errno.h>
39 #include <locale.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <termios.h>
44 #include <unistd.h>
45 #include <wchar.h>
46 #include <wctype.h>
47 
48 #define	BS	'\b'		/* backspace */
49 #define	TAB	'\t'		/* tab */
50 #define	SPACE	' '		/* space */
51 #define	NL	'\n'		/* newline */
52 #define	CR	'\r'		/* carriage return */
53 #define	ESC	'\033'		/* escape */
54 #define	SI	'\017'		/* shift in to normal character set */
55 #define	SO	'\016'		/* shift out to alternate character set */
56 #define	VT	'\013'		/* vertical tab (aka reverse line feed) */
57 #define	RLF	'7'		/* ESC-7 reverse line feed */
58 #define	RHLF	'8'		/* ESC-8 reverse half-line feed */
59 #define	FHLF	'9'		/* ESC-9 forward half-line feed */
60 
61 /* build up at least this many lines before flushing them out */
62 #define	BUFFER_MARGIN		32
63 
64 typedef char CSET;
65 
66 typedef struct char_str {
67 #define	CS_NORMAL	1
68 #define	CS_ALTERNATE	2
69 	short		c_column;	/* column character is in */
70 	CSET		c_set;		/* character set (currently only 2) */
71 	wchar_t		c_char;		/* character in question */
72 	int		c_width;	/* character width */
73 } CHAR;
74 
75 typedef struct line_str LINE;
76 struct line_str {
77 	CHAR	*l_line;		/* characters on the line */
78 	LINE	*l_prev;		/* previous line */
79 	LINE	*l_next;		/* next line */
80 	int	l_lsize;		/* allocated sizeof l_line */
81 	int	l_line_len;		/* strlen(l_line) */
82 	int	l_needs_sort;		/* set if chars went in out of order */
83 	int	l_max_col;		/* max column in the line */
84 };
85 
86 static void	addto_lineno(int *, int);
87 static LINE    *alloc_line(void);
88 static void	dowarn(int);
89 static void	flush_line(LINE *);
90 static void	flush_lines(int);
91 static void	flush_blanks(void);
92 static void	free_line(LINE *);
93 static void	usage(void);
94 
95 static CSET	last_set;		/* char_set of last char printed */
96 static LINE    *lines;
97 static int	compress_spaces;	/* if doing space -> tab conversion */
98 static int	fine;			/* if `fine' resolution (half lines) */
99 static int	max_bufd_lines;		/* max # of half lines to keep in memory */
100 static int	nblank_lines;		/* # blanks after last flushed line */
101 static int	no_backspaces;		/* if not to output any backspaces */
102 static int	pass_unknown_seqs;	/* pass unknown control sequences */
103 
104 #define	PUTC(ch) \
105 	do {					\
106 		if (putwchar(ch) == WEOF)	\
107 			errx(1, "write error");	\
108 	} while (0)
109 
110 int
111 main(int argc, char **argv)
112 {
113 	wint_t ch;
114 	CHAR *c;
115 	CSET cur_set;			/* current character set */
116 	LINE *l;			/* current line */
117 	int extra_lines;		/* # of lines above first line */
118 	int cur_col;			/* current column */
119 	int cur_line;			/* line number of current position */
120 	int max_line;			/* max value of cur_line */
121 	int this_line;			/* line l points to */
122 	int nflushd_lines;		/* number of lines that were flushed */
123 	int adjust, opt, warned, width;
124 	const char *errstr;
125 
126 	setlocale(LC_CTYPE, "");
127 
128 	max_bufd_lines = 256;
129 	compress_spaces = 1;		/* compress spaces into tabs */
130 	while ((opt = getopt(argc, argv, "bfhl:px")) != -1)
131 		switch (opt) {
132 		case 'b':		/* do not output backspaces */
133 			no_backspaces = 1;
134 			break;
135 		case 'f':		/* allow half forward line feeds */
136 			fine = 1;
137 			break;
138 		case 'h':		/* compress spaces into tabs */
139 			compress_spaces = 1;
140 			break;
141 		case 'l':		/* buffered line count */
142 			max_bufd_lines = strtonum(optarg, 1,
143 			    (INT_MAX - BUFFER_MARGIN) / 2, &errstr) * 2;
144 			if (errstr != NULL)
145 				errx(1, "bad -l argument, %s: %s", errstr,
146 					optarg);
147 			break;
148 		case 'p':		/* pass unknown control sequences */
149 			pass_unknown_seqs = 1;
150 			break;
151 		case 'x':		/* do not compress spaces into tabs */
152 			compress_spaces = 0;
153 			break;
154 		case '?':
155 		default:
156 			usage();
157 		}
158 
159 	if (optind != argc)
160 		usage();
161 
162 	adjust = cur_col = extra_lines = warned = 0;
163 	cur_line = max_line = nflushd_lines = this_line = 0;
164 	cur_set = last_set = CS_NORMAL;
165 	lines = l = alloc_line();
166 
167 	while ((ch = getwchar()) != WEOF) {
168 		if (!iswgraph(ch)) {
169 			switch (ch) {
170 			case BS:		/* can't go back further */
171 				if (cur_col == 0)
172 					continue;
173 				--cur_col;
174 				continue;
175 			case CR:
176 				cur_col = 0;
177 				continue;
178 			case ESC:		/* just ignore EOF */
179 				switch (getwchar()) {
180 				/*
181 				 * In the input stream, accept both the
182 				 * XPG5 sequences ESC-digit and the
183 				 * traditional BSD sequences ESC-ctrl.
184 				 */
185 				case '\007':
186 					/* FALLTHROUGH */
187 				case RLF:
188 					addto_lineno(&cur_line, -2);
189 					break;
190 				case '\010':
191 					/* FALLTHROUGH */
192 				case RHLF:
193 					addto_lineno(&cur_line, -1);
194 					break;
195 				case '\011':
196 					/* FALLTHROUGH */
197 				case FHLF:
198 					addto_lineno(&cur_line, 1);
199 					if (cur_line > max_line)
200 						max_line = cur_line;
201 				}
202 				continue;
203 			case NL:
204 				addto_lineno(&cur_line, 2);
205 				if (cur_line > max_line)
206 					max_line = cur_line;
207 				cur_col = 0;
208 				continue;
209 			case SPACE:
210 				++cur_col;
211 				continue;
212 			case SI:
213 				cur_set = CS_NORMAL;
214 				continue;
215 			case SO:
216 				cur_set = CS_ALTERNATE;
217 				continue;
218 			case TAB:		/* adjust column */
219 				cur_col |= 7;
220 				++cur_col;
221 				continue;
222 			case VT:
223 				addto_lineno(&cur_line, -2);
224 				continue;
225 			}
226 			if (iswspace(ch)) {
227 				if ((width = wcwidth(ch)) > 0)
228 					cur_col += width;
229 				continue;
230 			}
231 			if (!pass_unknown_seqs)
232 				continue;
233 		}
234 
235 		/* Must stuff ch in a line - are we at the right one? */
236 		if (cur_line + adjust != this_line) {
237 			LINE *lnew;
238 
239 			/* round up to next line */
240 			adjust = !fine && (cur_line & 1);
241 
242 			if (cur_line + adjust < this_line) {
243 				while (cur_line + adjust < this_line &&
244 				    l->l_prev != NULL) {
245 					l = l->l_prev;
246 					this_line--;
247 				}
248 				if (cur_line + adjust < this_line) {
249 					if (nflushd_lines == 0) {
250 						/*
251 						 * Allow backup past first
252 						 * line if nothing has been
253 						 * flushed yet.
254 						 */
255 						while (cur_line + adjust
256 						    < this_line) {
257 							lnew = alloc_line();
258 							l->l_prev = lnew;
259 							lnew->l_next = l;
260 							l = lines = lnew;
261 							extra_lines++;
262 							this_line--;
263 						}
264 					} else {
265 						if (!warned++)
266 							dowarn(cur_line);
267 						cur_line = this_line - adjust;
268 					}
269 				}
270 			} else {
271 				/* may need to allocate here */
272 				while (cur_line + adjust > this_line) {
273 					if (l->l_next == NULL) {
274 						l->l_next = alloc_line();
275 						l->l_next->l_prev = l;
276 					}
277 					l = l->l_next;
278 					this_line++;
279 				}
280 			}
281 			if (this_line > nflushd_lines &&
282 			    this_line - nflushd_lines >=
283 			    max_bufd_lines + BUFFER_MARGIN) {
284 				if (extra_lines) {
285 					flush_lines(extra_lines);
286 					extra_lines = 0;
287 				}
288 				flush_lines(this_line - nflushd_lines -
289 				    max_bufd_lines);
290 				nflushd_lines = this_line - max_bufd_lines;
291 			}
292 		}
293 		/* grow line's buffer? */
294 		if (l->l_line_len + 1 >= l->l_lsize) {
295 			int need;
296 
297 			need = l->l_lsize ? l->l_lsize * 2 : 90;
298 			if ((l->l_line = realloc(l->l_line,
299 			    (unsigned)need * sizeof(CHAR))) == NULL)
300 				err(1, NULL);
301 			l->l_lsize = need;
302 		}
303 		c = &l->l_line[l->l_line_len++];
304 		c->c_char = ch;
305 		c->c_set = cur_set;
306 		c->c_column = cur_col;
307 		c->c_width = wcwidth(ch);
308 		/*
309 		 * If things are put in out of order, they will need sorting
310 		 * when it is flushed.
311 		 */
312 		if (cur_col < l->l_max_col)
313 			l->l_needs_sort = 1;
314 		else
315 			l->l_max_col = cur_col;
316 		if (c->c_width > 0)
317 			cur_col += c->c_width;
318 	}
319 	if (ferror(stdin))
320 		err(1, NULL);
321 	if (extra_lines)
322 		flush_lines(extra_lines);
323 
324 	/* goto the last line that had a character on it */
325 	for (; l->l_next; l = l->l_next)
326 		this_line++;
327 	flush_lines(this_line - nflushd_lines + 1);
328 
329 	/* make sure we leave things in a sane state */
330 	if (last_set != CS_NORMAL)
331 		PUTC(SI);
332 
333 	/* flush out the last few blank lines */
334 	if (max_line > this_line)
335 		nblank_lines = max_line - this_line;
336 	if (max_line & 1)
337 		nblank_lines++;
338 	flush_blanks();
339 	exit(0);
340 }
341 
342 static void
343 flush_lines(int nflush)
344 {
345 	LINE *l;
346 
347 	while (--nflush >= 0) {
348 		l = lines;
349 		lines = l->l_next;
350 		if (l->l_line) {
351 			flush_blanks();
352 			flush_line(l);
353 		}
354 		if (l->l_line || l->l_next)
355 			nblank_lines++;
356 		if (l->l_line)
357 			free(l->l_line);
358 		free_line(l);
359 	}
360 	if (lines)
361 		lines->l_prev = NULL;
362 }
363 
364 /*
365  * Print a number of newline/half newlines.  If fine flag is set, nblank_lines
366  * is the number of half line feeds, otherwise it is the number of whole line
367  * feeds.
368  */
369 static void
370 flush_blanks(void)
371 {
372 	int half, i, nb;
373 
374 	half = 0;
375 	nb = nblank_lines;
376 	if (nb & 1) {
377 		if (fine)
378 			half = 1;
379 		else
380 			nb++;
381 	}
382 	nb /= 2;
383 	for (i = nb; --i >= 0;)
384 		PUTC('\n');
385 	if (half) {
386 		PUTC(ESC);
387 		PUTC(FHLF);
388 		if (!nb)
389 			PUTC('\r');
390 	}
391 	nblank_lines = 0;
392 }
393 
394 /*
395  * Write a line to stdout taking care of space to tab conversion (-h flag)
396  * and character set shifts.
397  */
398 static void
399 flush_line(LINE *l)
400 {
401 	CHAR *c, *endc;
402 	int i, j, nchars, last_col, save, this_col, tot;
403 
404 	last_col = 0;
405 	nchars = l->l_line_len;
406 
407 	if (l->l_needs_sort) {
408 		static CHAR *sorted;
409 		static int count_size, *count, sorted_size;
410 
411 		/*
412 		 * Do an O(n) sort on l->l_line by column being careful to
413 		 * preserve the order of characters in the same column.
414 		 */
415 		if (l->l_lsize > sorted_size) {
416 			sorted_size = l->l_lsize;
417 			if ((sorted = realloc(sorted,
418 			    (unsigned)sizeof(CHAR) * sorted_size)) == NULL)
419 				err(1, NULL);
420 		}
421 		if (l->l_max_col >= count_size) {
422 			count_size = l->l_max_col + 1;
423 			if ((count = realloc(count,
424 			    (unsigned)sizeof(int) * count_size)) == NULL)
425 				err(1, NULL);
426 		}
427 		memset(count, 0, sizeof(int) * l->l_max_col + 1);
428 		for (i = nchars, c = l->l_line; --i >= 0; c++)
429 			count[c->c_column]++;
430 
431 		/*
432 		 * calculate running total (shifted down by 1) to use as
433 		 * indices into new line.
434 		 */
435 		for (tot = 0, i = 0; i <= l->l_max_col; i++) {
436 			save = count[i];
437 			count[i] = tot;
438 			tot += save;
439 		}
440 
441 		for (i = nchars, c = l->l_line; --i >= 0; c++)
442 			sorted[count[c->c_column]++] = *c;
443 		c = sorted;
444 	} else
445 		c = l->l_line;
446 	while (nchars > 0) {
447 		this_col = c->c_column;
448 		endc = c;
449 		do {
450 			++endc;
451 		} while (--nchars > 0 && this_col == endc->c_column);
452 
453 		/* if -b only print last character */
454 		if (no_backspaces) {
455 			c = endc - 1;
456 			if (nchars > 0 &&
457 			    this_col + c->c_width > endc->c_column)
458 				continue;
459 		}
460 
461 		if (this_col > last_col) {
462 			int nspace = this_col - last_col;
463 
464 			if (compress_spaces && nspace > 1) {
465 				while (1) {
466 					int tab_col, tab_size;
467 
468 					tab_col = (last_col + 8) & ~7;
469 					if (tab_col > this_col)
470 						break;
471 					tab_size = tab_col - last_col;
472 					if (tab_size == 1)
473 						PUTC(' ');
474 					else
475 						PUTC('\t');
476 					nspace -= tab_size;
477 					last_col = tab_col;
478 				}
479 			}
480 			while (--nspace >= 0)
481 				PUTC(' ');
482 			last_col = this_col;
483 		}
484 
485 		for (;;) {
486 			if (c->c_set != last_set) {
487 				switch (c->c_set) {
488 				case CS_NORMAL:
489 					PUTC(SI);
490 					break;
491 				case CS_ALTERNATE:
492 					PUTC(SO);
493 				}
494 				last_set = c->c_set;
495 			}
496 			PUTC(c->c_char);
497 			if ((c + 1) < endc)
498 				for (j = 0; j < c->c_width; j++)
499 					PUTC('\b');
500 			if (++c >= endc)
501 				break;
502 		}
503 		last_col += (c - 1)->c_width;
504 	}
505 }
506 
507 /*
508  * Increment or decrement a line number, checking for overflow.
509  * Stop one below INT_MAX such that the adjust variable is safe.
510  */
511 void
512 addto_lineno(int *lno, int offset)
513 {
514 	if (offset > 0) {
515 		if (*lno >= INT_MAX - offset)
516 			errx(1, "too many lines");
517 	} else {
518 		if (*lno < INT_MIN - offset)
519 			errx(1, "too many reverse line feeds");
520 	}
521 	*lno += offset;
522 }
523 
524 #define	NALLOC 64
525 
526 static LINE *line_freelist;
527 
528 static LINE *
529 alloc_line(void)
530 {
531 	LINE *l;
532 	int i;
533 
534 	if (!line_freelist) {
535 		if ((l = realloc(NULL, sizeof(LINE) * NALLOC)) == NULL)
536 			err(1, NULL);
537 		line_freelist = l;
538 		for (i = 1; i < NALLOC; i++, l++)
539 			l->l_next = l + 1;
540 		l->l_next = NULL;
541 	}
542 	l = line_freelist;
543 	line_freelist = l->l_next;
544 
545 	memset(l, 0, sizeof(LINE));
546 	return (l);
547 }
548 
549 static void
550 free_line(LINE *l)
551 {
552 
553 	l->l_next = line_freelist;
554 	line_freelist = l;
555 }
556 
557 static void
558 usage(void)
559 {
560 
561 	fprintf(stderr, "usage: col [-bfhpx] [-l nline]\n");
562 	exit(1);
563 }
564 
565 static void
566 dowarn(int line)
567 {
568 
569 	warnx("warning: can't back up %s",
570 		line < 0 ? "past first line" : "-- line already flushed");
571 }
572