xref: /dragonfly/usr.bin/col/col.c (revision 1e9c07e1)
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 <limits.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 	setlocale(LC_CTYPE, "");
128 
129 	max_bufd_lines = 256;
130 	compress_spaces = 1;		/* compress spaces into tabs */
131 	while ((opt = getopt(argc, argv, "bfhl:px")) != -1)
132 		switch (opt) {
133 		case 'b':		/* do not output backspaces */
134 			no_backspaces = 1;
135 			break;
136 		case 'f':		/* allow half forward line feeds */
137 			fine = 1;
138 			break;
139 		case 'h':		/* compress spaces into tabs */
140 			compress_spaces = 1;
141 			break;
142 		case 'l':		/* buffered line count */
143 			max_bufd_lines = strtonum(optarg, 1,
144 			    (INT_MAX - BUFFER_MARGIN) / 2, &errstr) * 2;
145 			if (errstr != NULL)
146 				errx(1, "bad -l argument, %s: %s", errstr,
147 					optarg);
148 			break;
149 		case 'p':		/* pass unknown control sequences */
150 			pass_unknown_seqs = 1;
151 			break;
152 		case 'x':		/* do not compress spaces into tabs */
153 			compress_spaces = 0;
154 			break;
155 		case '?':
156 		default:
157 			usage();
158 		}
159 
160 	if (optind != argc)
161 		usage();
162 
163 	adjust = cur_col = extra_lines = warned = 0;
164 	cur_line = max_line = nflushd_lines = this_line = 0;
165 	cur_set = last_set = CS_NORMAL;
166 	lines = l = alloc_line();
167 
168 	while ((ch = getwchar()) != WEOF) {
169 		if (!iswgraph(ch)) {
170 			switch (ch) {
171 			case BS:		/* can't go back further */
172 				if (cur_col == 0)
173 					continue;
174 				--cur_col;
175 				continue;
176 			case CR:
177 				cur_col = 0;
178 				continue;
179 			case ESC:		/* just ignore EOF */
180 				switch (getwchar()) {
181 				/*
182 				 * In the input stream, accept both the
183 				 * XPG5 sequences ESC-digit and the
184 				 * traditional BSD sequences ESC-ctrl.
185 				 */
186 				case '\007':
187 					/* FALLTHROUGH */
188 				case RLF:
189 					addto_lineno(&cur_line, -2);
190 					break;
191 				case '\010':
192 					/* FALLTHROUGH */
193 				case RHLF:
194 					addto_lineno(&cur_line, -1);
195 					break;
196 				case '\011':
197 					/* FALLTHROUGH */
198 				case FHLF:
199 					addto_lineno(&cur_line, 1);
200 					if (cur_line > max_line)
201 						max_line = cur_line;
202 				}
203 				continue;
204 			case NL:
205 				addto_lineno(&cur_line, 2);
206 				if (cur_line > max_line)
207 					max_line = cur_line;
208 				cur_col = 0;
209 				continue;
210 			case SPACE:
211 				++cur_col;
212 				continue;
213 			case SI:
214 				cur_set = CS_NORMAL;
215 				continue;
216 			case SO:
217 				cur_set = CS_ALTERNATE;
218 				continue;
219 			case TAB:		/* adjust column */
220 				cur_col |= 7;
221 				++cur_col;
222 				continue;
223 			case VT:
224 				addto_lineno(&cur_line, -2);
225 				continue;
226 			}
227 			if (iswspace(ch)) {
228 				if ((width = wcwidth(ch)) > 0)
229 					cur_col += width;
230 				continue;
231 			}
232 			if (!pass_unknown_seqs)
233 				continue;
234 		}
235 
236 		/* Must stuff ch in a line - are we at the right one? */
237 		if (cur_line + adjust != this_line) {
238 			LINE *lnew;
239 
240 			/* round up to next line */
241 			adjust = !fine && (cur_line & 1);
242 
243 			if (cur_line + adjust < this_line) {
244 				while (cur_line + adjust < this_line &&
245 				    l->l_prev != NULL) {
246 					l = l->l_prev;
247 					this_line--;
248 				}
249 				if (cur_line + adjust < this_line) {
250 					if (nflushd_lines == 0) {
251 						/*
252 						 * Allow backup past first
253 						 * line if nothing has been
254 						 * flushed yet.
255 						 */
256 						while (cur_line + adjust
257 						    < this_line) {
258 							lnew = alloc_line();
259 							l->l_prev = lnew;
260 							lnew->l_next = l;
261 							l = lines = lnew;
262 							extra_lines++;
263 							this_line--;
264 						}
265 					} else {
266 						if (!warned++)
267 							dowarn(cur_line);
268 						cur_line = this_line - adjust;
269 					}
270 				}
271 			} else {
272 				/* may need to allocate here */
273 				while (cur_line + adjust > this_line) {
274 					if (l->l_next == NULL) {
275 						l->l_next = alloc_line();
276 						l->l_next->l_prev = l;
277 					}
278 					l = l->l_next;
279 					this_line++;
280 				}
281 			}
282 			if (this_line > nflushd_lines &&
283 			    this_line - nflushd_lines >=
284 			    max_bufd_lines + BUFFER_MARGIN) {
285 				if (extra_lines) {
286 					flush_lines(extra_lines);
287 					extra_lines = 0;
288 				}
289 				flush_lines(this_line - nflushd_lines -
290 				    max_bufd_lines);
291 				nflushd_lines = this_line - max_bufd_lines;
292 			}
293 		}
294 		/* grow line's buffer? */
295 		if (l->l_line_len + 1 >= l->l_lsize) {
296 			int need;
297 
298 			need = l->l_lsize ? l->l_lsize * 2 : 90;
299 			if ((l->l_line = realloc(l->l_line,
300 			    (unsigned)need * sizeof(CHAR))) == NULL)
301 				err(1, NULL);
302 			l->l_lsize = need;
303 		}
304 		c = &l->l_line[l->l_line_len++];
305 		c->c_char = ch;
306 		c->c_set = cur_set;
307 		c->c_column = cur_col;
308 		c->c_width = wcwidth(ch);
309 		/*
310 		 * If things are put in out of order, they will need sorting
311 		 * when it is flushed.
312 		 */
313 		if (cur_col < l->l_max_col)
314 			l->l_needs_sort = 1;
315 		else
316 			l->l_max_col = cur_col;
317 		if (c->c_width > 0)
318 			cur_col += c->c_width;
319 	}
320 	if (ferror(stdin))
321 		err(1, NULL);
322 	if (extra_lines)
323 		flush_lines(extra_lines);
324 
325 	/* goto the last line that had a character on it */
326 	for (; l->l_next; l = l->l_next)
327 		this_line++;
328 	flush_lines(this_line - nflushd_lines + 1);
329 
330 	/* make sure we leave things in a sane state */
331 	if (last_set != CS_NORMAL)
332 		PUTC(SI);
333 
334 	/* flush out the last few blank lines */
335 	if (max_line > this_line)
336 		nblank_lines = max_line - this_line;
337 	if (max_line & 1)
338 		nblank_lines++;
339 	flush_blanks();
340 	exit(0);
341 }
342 
343 static void
flush_lines(int nflush)344 flush_lines(int nflush)
345 {
346 	LINE *l;
347 
348 	while (--nflush >= 0) {
349 		l = lines;
350 		lines = l->l_next;
351 		if (l->l_line) {
352 			flush_blanks();
353 			flush_line(l);
354 		}
355 		if (l->l_line || l->l_next)
356 			nblank_lines++;
357 		if (l->l_line)
358 			free(l->l_line);
359 		free_line(l);
360 	}
361 	if (lines)
362 		lines->l_prev = NULL;
363 }
364 
365 /*
366  * Print a number of newline/half newlines.  If fine flag is set, nblank_lines
367  * is the number of half line feeds, otherwise it is the number of whole line
368  * feeds.
369  */
370 static void
flush_blanks(void)371 flush_blanks(void)
372 {
373 	int half, i, nb;
374 
375 	half = 0;
376 	nb = nblank_lines;
377 	if (nb & 1) {
378 		if (fine)
379 			half = 1;
380 		else
381 			nb++;
382 	}
383 	nb /= 2;
384 	for (i = nb; --i >= 0;)
385 		PUTC('\n');
386 	if (half) {
387 		PUTC(ESC);
388 		PUTC(FHLF);
389 		if (!nb)
390 			PUTC('\r');
391 	}
392 	nblank_lines = 0;
393 }
394 
395 /*
396  * Write a line to stdout taking care of space to tab conversion (-h flag)
397  * and character set shifts.
398  */
399 static void
flush_line(LINE * l)400 flush_line(LINE *l)
401 {
402 	CHAR *c, *endc;
403 	int i, j, nchars, last_col, save, this_col, tot;
404 
405 	last_col = 0;
406 	nchars = l->l_line_len;
407 
408 	if (l->l_needs_sort) {
409 		static CHAR *sorted;
410 		static int count_size, *count, sorted_size;
411 
412 		/*
413 		 * Do an O(n) sort on l->l_line by column being careful to
414 		 * preserve the order of characters in the same column.
415 		 */
416 		if (l->l_lsize > sorted_size) {
417 			sorted_size = l->l_lsize;
418 			if ((sorted = realloc(sorted,
419 			    (unsigned)sizeof(CHAR) * sorted_size)) == NULL)
420 				err(1, NULL);
421 		}
422 		if (l->l_max_col >= count_size) {
423 			count_size = l->l_max_col + 1;
424 			if ((count = realloc(count,
425 			    (unsigned)sizeof(int) * count_size)) == NULL)
426 				err(1, NULL);
427 		}
428 		memset(count, 0, sizeof(int) * l->l_max_col + 1);
429 		for (i = nchars, c = l->l_line; --i >= 0; c++)
430 			count[c->c_column]++;
431 
432 		/*
433 		 * calculate running total (shifted down by 1) to use as
434 		 * indices into new line.
435 		 */
436 		for (tot = 0, i = 0; i <= l->l_max_col; i++) {
437 			save = count[i];
438 			count[i] = tot;
439 			tot += save;
440 		}
441 
442 		for (i = nchars, c = l->l_line; --i >= 0; c++)
443 			sorted[count[c->c_column]++] = *c;
444 		c = sorted;
445 	} else
446 		c = l->l_line;
447 	while (nchars > 0) {
448 		this_col = c->c_column;
449 		endc = c;
450 		do {
451 			++endc;
452 		} while (--nchars > 0 && this_col == endc->c_column);
453 
454 		/* if -b only print last character */
455 		if (no_backspaces) {
456 			c = endc - 1;
457 			if (nchars > 0 &&
458 			    this_col + c->c_width > endc->c_column)
459 				continue;
460 		}
461 
462 		if (this_col > last_col) {
463 			int nspace = this_col - last_col;
464 
465 			if (compress_spaces && nspace > 1) {
466 				while (1) {
467 					int tab_col, tab_size;
468 
469 					tab_col = (last_col + 8) & ~7;
470 					if (tab_col > this_col)
471 						break;
472 					tab_size = tab_col - last_col;
473 					if (tab_size == 1)
474 						PUTC(' ');
475 					else
476 						PUTC('\t');
477 					nspace -= tab_size;
478 					last_col = tab_col;
479 				}
480 			}
481 			while (--nspace >= 0)
482 				PUTC(' ');
483 			last_col = this_col;
484 		}
485 
486 		for (;;) {
487 			if (c->c_set != last_set) {
488 				switch (c->c_set) {
489 				case CS_NORMAL:
490 					PUTC(SI);
491 					break;
492 				case CS_ALTERNATE:
493 					PUTC(SO);
494 				}
495 				last_set = c->c_set;
496 			}
497 			PUTC(c->c_char);
498 			if ((c + 1) < endc)
499 				for (j = 0; j < c->c_width; j++)
500 					PUTC('\b');
501 			if (++c >= endc)
502 				break;
503 		}
504 		last_col += (c - 1)->c_width;
505 	}
506 }
507 
508 /*
509  * Increment or decrement a line number, checking for overflow.
510  * Stop one below INT_MAX such that the adjust variable is safe.
511  */
512 void
addto_lineno(int * lno,int offset)513 addto_lineno(int *lno, int offset)
514 {
515 	if (offset > 0) {
516 		if (*lno >= INT_MAX - offset)
517 			errx(1, "too many lines");
518 	} else {
519 		if (*lno < INT_MIN - offset)
520 			errx(1, "too many reverse line feeds");
521 	}
522 	*lno += offset;
523 }
524 
525 #define	NALLOC 64
526 
527 static LINE *line_freelist;
528 
529 static LINE *
alloc_line(void)530 alloc_line(void)
531 {
532 	LINE *l;
533 	int i;
534 
535 	if (!line_freelist) {
536 		if ((l = realloc(NULL, sizeof(LINE) * NALLOC)) == NULL)
537 			err(1, NULL);
538 		line_freelist = l;
539 		for (i = 1; i < NALLOC; i++, l++)
540 			l->l_next = l + 1;
541 		l->l_next = NULL;
542 	}
543 	l = line_freelist;
544 	line_freelist = l->l_next;
545 
546 	memset(l, 0, sizeof(LINE));
547 	return (l);
548 }
549 
550 static void
free_line(LINE * l)551 free_line(LINE *l)
552 {
553 
554 	l->l_next = line_freelist;
555 	line_freelist = l;
556 }
557 
558 static void
usage(void)559 usage(void)
560 {
561 
562 	fprintf(stderr, "usage: col [-bfhpx] [-l nline]\n");
563 	exit(1);
564 }
565 
566 static void
dowarn(int line)567 dowarn(int line)
568 {
569 
570 	warnx("warning: can't back up %s",
571 		line < 0 ? "past first line" : "-- line already flushed");
572 }
573