xref: /openbsd-src/usr.bin/col/col.c (revision d13be5d47e4149db2549a9828e244d59dbc43f15)
1 /*	$OpenBSD: col.c,v 1.11 2009/10/27 23:59:36 deraadt Exp $	*/
2 /*	$NetBSD: col.c,v 1.7 1995/09/02 05:48:50 jtc Exp $	*/
3 
4 /*-
5  * Copyright (c) 1990, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Michael Rendell of the Memorial University of Newfoundland.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <ctype.h>
37 #include <err.h>
38 #include <string.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <unistd.h>
42 #include <limits.h>
43 
44 #define	BS	'\b'		/* backspace */
45 #define	TAB	'\t'		/* tab */
46 #define	SPACE	' '		/* space */
47 #define	NL	'\n'		/* newline */
48 #define	CR	'\r'		/* carriage return */
49 #define	ESC	'\033'		/* escape */
50 #define	SI	'\017'		/* shift in to normal character set */
51 #define	SO	'\016'		/* shift out to alternate character set */
52 #define	VT	'\013'		/* vertical tab (aka reverse line feed) */
53 #define	RLF	'\007'		/* ESC-07 reverse line feed */
54 #define	RHLF	'\010'		/* ESC-010 reverse half-line feed */
55 #define	FHLF	'\011'		/* ESC-011 forward half-line feed */
56 
57 /* build up at least this many lines before flushing them out */
58 #define	BUFFER_MARGIN		32
59 
60 typedef char CSET;
61 
62 typedef struct char_str {
63 #define	CS_NORMAL	1
64 #define	CS_ALTERNATE	2
65 	short		c_column;	/* column character is in */
66 	CSET		c_set;		/* character set (currently only 2) */
67 	char		c_char;		/* character in question */
68 } CHAR;
69 
70 typedef struct line_str LINE;
71 struct line_str {
72 	CHAR	*l_line;		/* characters on the line */
73 	LINE	*l_prev;		/* previous line */
74 	LINE	*l_next;		/* next line */
75 	int	l_lsize;		/* allocated sizeof l_line */
76 	int	l_line_len;		/* strlen(l_line) */
77 	int	l_needs_sort;		/* set if chars went in out of order */
78 	int	l_max_col;		/* max column in the line */
79 };
80 
81 LINE   *alloc_line(void);
82 void	dowarn(int);
83 void	flush_line(LINE *);
84 void	flush_lines(int);
85 void	flush_blanks(void);
86 void	free_line(LINE *);
87 void	usage(void);
88 void   *xmalloc(void *, size_t);
89 
90 CSET	last_set;		/* char_set of last char printed */
91 LINE   *lines;
92 int	compress_spaces;	/* if doing space -> tab conversion */
93 int	fine;			/* if `fine' resolution (half lines) */
94 int	max_bufd_lines;		/* max # lines to keep in memory */
95 int	nblank_lines;		/* # blanks after last flushed line */
96 int	no_backspaces;		/* if not to output any backspaces */
97 
98 #define	PUTC(ch) \
99 	if (putchar(ch) == EOF) \
100 		err(1, "stdout");
101 
102 int
103 main(int argc, char *argv[])
104 {
105 	int ch;
106 	CHAR *c;
107 	CSET cur_set;			/* current character set */
108 	LINE *l;			/* current line */
109 	int extra_lines;		/* # of lines above first line */
110 	int cur_col;			/* current column */
111 	int cur_line;			/* line number of current position */
112 	int max_line;			/* max value of cur_line */
113 	int this_line;			/* line l points to */
114 	int nflushd_lines;		/* number of lines that were flushed */
115 	int adjust, opt, warned;
116 	const char *errstr;
117 
118 	max_bufd_lines = 128;
119 	compress_spaces = 1;		/* compress spaces into tabs */
120 	while ((opt = getopt(argc, argv, "bfhl:x")) != -1)
121 		switch (opt) {
122 		case 'b':		/* do not output backspaces */
123 			no_backspaces = 1;
124 			break;
125 		case 'f':		/* allow half forward line feeds */
126 			fine = 1;
127 			break;
128 		case 'h':		/* compress spaces into tabs */
129 			compress_spaces = 1;
130 			break;
131 		case 'l':		/* buffered line count */
132 			max_bufd_lines = strtonum(optarg, 1, INT_MAX, &errstr);
133 			if (errstr != NULL)
134 				errx(1, "bad -l argument, %s: %s", errstr,
135 					optarg);
136 			break;
137 		case 'x':		/* do not compress spaces into tabs */
138 			compress_spaces = 0;
139 			break;
140 		case '?':
141 		default:
142 			usage();
143 		}
144 
145 	if (optind != argc)
146 		usage();
147 
148 	/* this value is in half lines */
149 	max_bufd_lines *= 2;
150 
151 	adjust = cur_col = extra_lines = warned = 0;
152 	cur_line = max_line = nflushd_lines = this_line = 0;
153 	cur_set = last_set = CS_NORMAL;
154 	lines = l = alloc_line();
155 
156 	while ((ch = getchar()) != EOF) {
157 		if (!isgraph(ch)) {
158 			switch (ch) {
159 			case BS:		/* can't go back further */
160 				if (cur_col == 0)
161 					continue;
162 				--cur_col;
163 				continue;
164 			case CR:
165 				cur_col = 0;
166 				continue;
167 			case ESC:		/* just ignore EOF */
168 				switch(getchar()) {
169 				case RLF:
170 					cur_line -= 2;
171 					break;
172 				case RHLF:
173 					cur_line--;
174 					break;
175 				case FHLF:
176 					cur_line++;
177 					if (cur_line > max_line)
178 						max_line = cur_line;
179 				}
180 				continue;
181 			case NL:
182 				cur_line += 2;
183 				if (cur_line > max_line)
184 					max_line = cur_line;
185 				cur_col = 0;
186 				continue;
187 			case SPACE:
188 				++cur_col;
189 				continue;
190 			case SI:
191 				cur_set = CS_NORMAL;
192 				continue;
193 			case SO:
194 				cur_set = CS_ALTERNATE;
195 				continue;
196 			case TAB:		/* adjust column */
197 				cur_col |= 7;
198 				++cur_col;
199 				continue;
200 			case VT:
201 				cur_line -= 2;
202 				continue;
203 			}
204 			continue;
205 		}
206 
207 		/* Must stuff ch in a line - are we at the right one? */
208 		if (cur_line != this_line - adjust) {
209 			LINE *lnew;
210 			int nmove;
211 
212 			adjust = 0;
213 			nmove = cur_line - this_line;
214 			if (!fine) {
215 				/* round up to next line */
216 				if (cur_line & 1) {
217 					adjust = 1;
218 					nmove++;
219 				}
220 			}
221 			if (nmove < 0) {
222 				for (; nmove < 0 && l->l_prev; nmove++)
223 					l = l->l_prev;
224 				if (nmove) {
225 					if (nflushd_lines == 0) {
226 						/*
227 						 * Allow backup past first
228 						 * line if nothing has been
229 						 * flushed yet.
230 						 */
231 						for (; nmove < 0; nmove++) {
232 							lnew = alloc_line();
233 							l->l_prev = lnew;
234 							lnew->l_next = l;
235 							l = lines = lnew;
236 							extra_lines++;
237 						}
238 					} else {
239 						if (!warned++)
240 							dowarn(cur_line);
241 						cur_line -= nmove;
242 					}
243 				}
244 			} else {
245 				/* may need to allocate here */
246 				for (; nmove > 0 && l->l_next; nmove--)
247 					l = l->l_next;
248 				for (; nmove > 0; nmove--) {
249 					lnew = alloc_line();
250 					lnew->l_prev = l;
251 					l->l_next = lnew;
252 					l = lnew;
253 				}
254 			}
255 			this_line = cur_line + adjust;
256 			nmove = this_line - nflushd_lines;
257 			if (nmove >= max_bufd_lines + BUFFER_MARGIN) {
258 				nflushd_lines += nmove - max_bufd_lines;
259 				flush_lines(nmove - max_bufd_lines);
260 			}
261 		}
262 		/* grow line's buffer? */
263 		if (l->l_line_len + 1 >= l->l_lsize) {
264 			int need;
265 
266 			need = l->l_lsize ? l->l_lsize * 2 : 90;
267 			l->l_line = (CHAR *)xmalloc((void *) l->l_line,
268 			    (unsigned) need * sizeof(CHAR));
269 			l->l_lsize = need;
270 		}
271 		c = &l->l_line[l->l_line_len++];
272 		c->c_char = ch;
273 		c->c_set = cur_set;
274 		c->c_column = cur_col;
275 		/*
276 		 * If things are put in out of order, they will need sorting
277 		 * when it is flushed.
278 		 */
279 		if (cur_col < l->l_max_col)
280 			l->l_needs_sort = 1;
281 		else
282 			l->l_max_col = cur_col;
283 		cur_col++;
284 	}
285 	if (max_line == 0)
286 		exit(0);	/* no lines, so just exit */
287 
288 	/* goto the last line that had a character on it */
289 	for (; l->l_next; l = l->l_next)
290 		this_line++;
291 	flush_lines(this_line - nflushd_lines + extra_lines + 1);
292 
293 	/* make sure we leave things in a sane state */
294 	if (last_set != CS_NORMAL)
295 		PUTC('\017');
296 
297 	/* flush out the last few blank lines */
298 	nblank_lines = max_line - this_line;
299 	if (max_line & 1)
300 		nblank_lines++;
301 	else if (!nblank_lines)
302 		/* missing a \n on the last line? */
303 		nblank_lines = 2;
304 	flush_blanks();
305 	exit(0);
306 }
307 
308 void
309 flush_lines(int nflush)
310 {
311 	LINE *l;
312 
313 	while (--nflush >= 0) {
314 		l = lines;
315 		lines = l->l_next;
316 		if (l->l_line) {
317 			flush_blanks();
318 			flush_line(l);
319 		}
320 		nblank_lines++;
321 		if (l->l_line)
322 			(void)free((void *)l->l_line);
323 		free_line(l);
324 	}
325 	if (lines)
326 		lines->l_prev = NULL;
327 }
328 
329 /*
330  * Print a number of newline/half newlines.  If fine flag is set, nblank_lines
331  * is the number of half line feeds, otherwise it is the number of whole line
332  * feeds.
333  */
334 void
335 flush_blanks(void)
336 {
337 	int half, i, nb;
338 
339 	half = 0;
340 	nb = nblank_lines;
341 	if (nb & 1) {
342 		if (fine)
343 			half = 1;
344 		else
345 			nb++;
346 	}
347 	nb /= 2;
348 	for (i = nb; --i >= 0;)
349 		PUTC('\n');
350 	if (half) {
351 		PUTC('\033');
352 		PUTC('9');
353 		if (!nb)
354 			PUTC('\r');
355 	}
356 	nblank_lines = 0;
357 }
358 
359 /*
360  * Write a line to stdout taking care of space to tab conversion (-h flag)
361  * and character set shifts.
362  */
363 void
364 flush_line(LINE *l)
365 {
366 	CHAR *c, *endc;
367 	int nchars, last_col, this_col;
368 
369 	last_col = 0;
370 	nchars = l->l_line_len;
371 
372 	if (l->l_needs_sort) {
373 		static CHAR *sorted;
374 		static int count_size, *count, i, save, sorted_size, tot;
375 
376 		/*
377 		 * Do an O(n) sort on l->l_line by column being careful to
378 		 * preserve the order of characters in the same column.
379 		 */
380 		if (l->l_lsize > sorted_size) {
381 			sorted_size = l->l_lsize;
382 			sorted = (CHAR *)xmalloc((void *)sorted,
383 			    (unsigned)sizeof(CHAR) * sorted_size);
384 		}
385 		if (l->l_max_col >= count_size) {
386 			count_size = l->l_max_col + 1;
387 			count = (int *)xmalloc((void *)count,
388 			    (unsigned)sizeof(int) * count_size);
389 		}
390 		memset((char *)count, 0, sizeof(int) * l->l_max_col + 1);
391 		for (i = nchars, c = l->l_line; --i >= 0; c++)
392 			count[c->c_column]++;
393 
394 		/*
395 		 * calculate running total (shifted down by 1) to use as
396 		 * indices into new line.
397 		 */
398 		for (tot = 0, i = 0; i <= l->l_max_col; i++) {
399 			save = count[i];
400 			count[i] = tot;
401 			tot += save;
402 		}
403 
404 		for (i = nchars, c = l->l_line; --i >= 0; c++)
405 			sorted[count[c->c_column]++] = *c;
406 		c = sorted;
407 	} else
408 		c = l->l_line;
409 	while (nchars > 0) {
410 		this_col = c->c_column;
411 		endc = c;
412 		do {
413 			++endc;
414 		} while (--nchars > 0 && this_col == endc->c_column);
415 
416 		/* if -b only print last character */
417 		if (no_backspaces)
418 			c = endc - 1;
419 
420 		if (this_col > last_col) {
421 			int nspace = this_col - last_col;
422 
423 			if (compress_spaces && nspace > 1) {
424 				int ntabs;
425 
426 				ntabs = ((last_col % 8) + nspace) / 8;
427 				if (ntabs) {
428 					nspace -= (ntabs * 8) - (last_col % 8);
429 					while (--ntabs >= 0)
430 						PUTC('\t');
431 				}
432 			}
433 			while (--nspace >= 0)
434 				PUTC(' ');
435 			last_col = this_col;
436 		}
437 		last_col++;
438 
439 		for (;;) {
440 			if (c->c_set != last_set) {
441 				switch (c->c_set) {
442 				case CS_NORMAL:
443 					PUTC('\017');
444 					break;
445 				case CS_ALTERNATE:
446 					PUTC('\016');
447 				}
448 				last_set = c->c_set;
449 			}
450 			PUTC(c->c_char);
451 			if (++c >= endc)
452 				break;
453 			PUTC('\b');
454 		}
455 	}
456 }
457 
458 #define	NALLOC 64
459 
460 static LINE *line_freelist;
461 
462 LINE *
463 alloc_line(void)
464 {
465 	LINE *l;
466 	int i;
467 
468 	if (!line_freelist) {
469 		l = (LINE *)xmalloc(NULL, sizeof(LINE) * NALLOC);
470 		line_freelist = l;
471 		for (i = 1; i < NALLOC; i++, l++)
472 			l->l_next = l + 1;
473 		l->l_next = NULL;
474 	}
475 	l = line_freelist;
476 	line_freelist = l->l_next;
477 
478 	memset(l, 0, sizeof(LINE));
479 	return (l);
480 }
481 
482 void
483 free_line(LINE *l)
484 {
485 
486 	l->l_next = line_freelist;
487 	line_freelist = l;
488 }
489 
490 void *
491 xmalloc(void *p, size_t size)
492 {
493 
494 	if (!(p = (void *)realloc(p, size)))
495 		err(1, "realloc failed");
496 	return (p);
497 }
498 
499 void
500 usage(void)
501 {
502 	(void)fprintf(stderr, "usage: col [-bfhx] [-l num]\n");
503 	exit(1);
504 }
505 
506 void
507 dowarn(int line)
508 {
509 
510 	warnx("warning: can't back up %s",
511 		line < 0 ? "past first line" : "-- line already flushed");
512 }
513