xref: /original-bsd/usr.bin/col/col.c (revision b55621b9)
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  * %sccs.include.redist.c%
9  */
10 
11 #ifndef lint
12 static char copyright[] =
13 "@(#) Copyright (c) 1990, 1993, 1994\n\
14 	The Regents of the University of California.  All rights reserved.\n";
15 #endif /* not lint */
16 
17 #ifndef lint
18 static char sccsid[] = "@(#)col.c	8.4 (Berkeley) 04/28/95";
19 #endif /* not lint */
20 
21 #include <ctype.h>
22 #include <err.h>
23 #include <string.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 
27 #define	BS	'\b'		/* backspace */
28 #define	TAB	'\t'		/* tab */
29 #define	SPACE	' '		/* space */
30 #define	NL	'\n'		/* newline */
31 #define	CR	'\r'		/* carriage return */
32 #define	ESC	'\033'		/* escape */
33 #define	SI	'\017'		/* shift in to normal character set */
34 #define	SO	'\016'		/* shift out to alternate character set */
35 #define	VT	'\013'		/* vertical tab (aka reverse line feed) */
36 #define	RLF	'\007'		/* ESC-07 reverse line feed */
37 #define	RHLF	'\010'		/* ESC-010 reverse half-line feed */
38 #define	FHLF	'\011'		/* ESC-011 forward half-line feed */
39 
40 /* build up at least this many lines before flushing them out */
41 #define	BUFFER_MARGIN		32
42 
43 typedef char CSET;
44 
45 typedef struct char_str {
46 #define	CS_NORMAL	1
47 #define	CS_ALTERNATE	2
48 	short		c_column;	/* column character is in */
49 	CSET		c_set;		/* character set (currently only 2) */
50 	char		c_char;		/* character in question */
51 } CHAR;
52 
53 typedef struct line_str LINE;
54 struct line_str {
55 	CHAR	*l_line;		/* characters on the line */
56 	LINE	*l_prev;		/* previous line */
57 	LINE	*l_next;		/* next line */
58 	int	l_lsize;		/* allocated sizeof l_line */
59 	int	l_line_len;		/* strlen(l_line) */
60 	int	l_needs_sort;		/* set if chars went in out of order */
61 	int	l_max_col;		/* max column in the line */
62 };
63 
64 LINE   *alloc_line __P((void));
65 void	dowarn __P((int));
66 void	flush_line __P((LINE *));
67 void	flush_lines __P((int));
68 void	flush_blanks __P((void));
69 void	free_line __P((LINE *));
70 void	usage __P((void));
71 void	wrerr __P((void));
72 void   *xmalloc __P((void *, size_t));
73 
74 CSET	last_set;		/* char_set of last char printed */
75 LINE   *lines;
76 int	compress_spaces;	/* if doing space -> tab conversion */
77 int	fine;			/* if `fine' resolution (half lines) */
78 int	max_bufd_lines;		/* max # lines to keep in memory */
79 int	nblank_lines;		/* # blanks after last flushed line */
80 int	no_backspaces;		/* if not to output any backspaces */
81 
82 #define	PUTC(ch) \
83 	if (putchar(ch) == EOF) \
84 		wrerr();
85 
86 int
87 main(argc, argv)
88 	int argc;
89 	char **argv;
90 {
91 	int ch;
92 	CHAR *c;
93 	CSET cur_set;			/* current character set */
94 	LINE *l;			/* current line */
95 	int extra_lines;		/* # of lines above first line */
96 	int cur_col;			/* current column */
97 	int cur_line;			/* line number of current position */
98 	int max_line;			/* max value of cur_line */
99 	int this_line;			/* line l points to */
100 	int nflushd_lines;		/* number of lines that were flushed */
101 	int adjust, opt, warned;
102 
103 	max_bufd_lines = 128;
104 	compress_spaces = 1;		/* compress spaces into tabs */
105 	while ((opt = getopt(argc, argv, "bfhl:x")) != EOF)
106 		switch (opt) {
107 		case 'b':		/* do not output backspaces */
108 			no_backspaces = 1;
109 			break;
110 		case 'f':		/* allow half forward line feeds */
111 			fine = 1;
112 			break;
113 		case 'h':		/* compress spaces into tabs */
114 			compress_spaces = 1;
115 			break;
116 		case 'l':		/* buffered line count */
117 			if ((max_bufd_lines = atoi(optarg)) <= 0) {
118 				(void)fprintf(stderr,
119 				    "col: bad -l argument %s.\n", optarg);
120 				exit(1);
121 			}
122 			break;
123 		case 'x':		/* do not compress spaces into tabs */
124 			compress_spaces = 0;
125 			break;
126 		case '?':
127 		default:
128 			usage();
129 		}
130 
131 	if (optind != argc)
132 		usage();
133 
134 	/* this value is in half lines */
135 	max_bufd_lines *= 2;
136 
137 	adjust = cur_col = extra_lines = warned = 0;
138 	cur_line = max_line = nflushd_lines = this_line = 0;
139 	cur_set = last_set = CS_NORMAL;
140 	lines = l = alloc_line();
141 
142 	while ((ch = getchar()) != EOF) {
143 		if (!isgraph(ch)) {
144 			switch (ch) {
145 			case BS:		/* can't go back further */
146 				if (cur_col == 0)
147 					continue;
148 				--cur_col;
149 				continue;
150 			case CR:
151 				cur_col = 0;
152 				continue;
153 			case ESC:		/* just ignore EOF */
154 				switch(getchar()) {
155 				case RLF:
156 					cur_line -= 2;
157 					break;
158 				case RHLF:
159 					cur_line--;
160 					break;
161 				case FHLF:
162 					cur_line++;
163 					if (cur_line > max_line)
164 						max_line = cur_line;
165 				}
166 				continue;
167 			case NL:
168 				cur_line += 2;
169 				if (cur_line > max_line)
170 					max_line = cur_line;
171 				cur_col = 0;
172 				continue;
173 			case SPACE:
174 				++cur_col;
175 				continue;
176 			case SI:
177 				cur_set = CS_NORMAL;
178 				continue;
179 			case SO:
180 				cur_set = CS_ALTERNATE;
181 				continue;
182 			case TAB:		/* adjust column */
183 				cur_col |= 7;
184 				++cur_col;
185 				continue;
186 			case VT:
187 				cur_line -= 2;
188 				continue;
189 			}
190 			continue;
191 		}
192 
193 		/* Must stuff ch in a line - are we at the right one? */
194 		if (cur_line != this_line - adjust) {
195 			LINE *lnew;
196 			int nmove;
197 
198 			adjust = 0;
199 			nmove = cur_line - this_line;
200 			if (!fine) {
201 				/* round up to next line */
202 				if (cur_line & 1) {
203 					adjust = 1;
204 					nmove++;
205 				}
206 			}
207 			if (nmove < 0) {
208 				for (; nmove < 0 && l->l_prev; nmove++)
209 					l = l->l_prev;
210 				if (nmove) {
211 					if (nflushd_lines == 0) {
212 						/*
213 						 * Allow backup past first
214 						 * line if nothing has been
215 						 * flushed yet.
216 						 */
217 						for (; nmove < 0; nmove++) {
218 							lnew = alloc_line();
219 							l->l_prev = lnew;
220 							lnew->l_next = l;
221 							l = lines = lnew;
222 							extra_lines++;
223 						}
224 					} else {
225 						if (!warned++)
226 							dowarn(cur_line);
227 						cur_line -= nmove;
228 					}
229 				}
230 			} else {
231 				/* may need to allocate here */
232 				for (; nmove > 0 && l->l_next; nmove--)
233 					l = l->l_next;
234 				for (; nmove > 0; nmove--) {
235 					lnew = alloc_line();
236 					lnew->l_prev = l;
237 					l->l_next = lnew;
238 					l = lnew;
239 				}
240 			}
241 			this_line = cur_line + adjust;
242 			nmove = this_line - nflushd_lines;
243 			if (nmove >= max_bufd_lines + BUFFER_MARGIN) {
244 				nflushd_lines += nmove - max_bufd_lines;
245 				flush_lines(nmove - max_bufd_lines);
246 			}
247 		}
248 		/* grow line's buffer? */
249 		if (l->l_line_len + 1 >= l->l_lsize) {
250 			int need;
251 
252 			need = l->l_lsize ? l->l_lsize * 2 : 90;
253 			l->l_line = (CHAR *)xmalloc((void *) l->l_line,
254 			    (unsigned) need * sizeof(CHAR));
255 			l->l_lsize = need;
256 		}
257 		c = &l->l_line[l->l_line_len++];
258 		c->c_char = ch;
259 		c->c_set = cur_set;
260 		c->c_column = cur_col;
261 		/*
262 		 * If things are put in out of order, they will need sorting
263 		 * when it is flushed.
264 		 */
265 		if (cur_col < l->l_max_col)
266 			l->l_needs_sort = 1;
267 		else
268 			l->l_max_col = cur_col;
269 		cur_col++;
270 	}
271 	if (max_line == 0)
272 		exit(0);	/* no lines, so just exit */
273 
274 	/* goto the last line that had a character on it */
275 	for (; l->l_next; l = l->l_next)
276 		this_line++;
277 	flush_lines(this_line - nflushd_lines + extra_lines + 1);
278 
279 	/* make sure we leave things in a sane state */
280 	if (last_set != CS_NORMAL)
281 		PUTC('\017');
282 
283 	/* flush out the last few blank lines */
284 	nblank_lines = max_line - this_line;
285 	if (max_line & 1)
286 		nblank_lines++;
287 	else if (!nblank_lines)
288 		/* missing a \n on the last line? */
289 		nblank_lines = 2;
290 	flush_blanks();
291 	exit(0);
292 }
293 
294 void
295 flush_lines(nflush)
296 	int nflush;
297 {
298 	LINE *l;
299 
300 	while (--nflush >= 0) {
301 		l = lines;
302 		lines = l->l_next;
303 		if (l->l_line) {
304 			flush_blanks();
305 			flush_line(l);
306 		}
307 		nblank_lines++;
308 		if (l->l_line)
309 			(void)free((void *)l->l_line);
310 		free_line(l);
311 	}
312 	if (lines)
313 		lines->l_prev = NULL;
314 }
315 
316 /*
317  * Print a number of newline/half newlines.  If fine flag is set, nblank_lines
318  * is the number of half line feeds, otherwise it is the number of whole line
319  * feeds.
320  */
321 void
322 flush_blanks()
323 {
324 	int half, i, nb;
325 
326 	half = 0;
327 	nb = nblank_lines;
328 	if (nb & 1) {
329 		if (fine)
330 			half = 1;
331 		else
332 			nb++;
333 	}
334 	nb /= 2;
335 	for (i = nb; --i >= 0;)
336 		PUTC('\n');
337 	if (half) {
338 		PUTC('\033');
339 		PUTC('9');
340 		if (!nb)
341 			PUTC('\r');
342 	}
343 	nblank_lines = 0;
344 }
345 
346 /*
347  * Write a line to stdout taking care of space to tab conversion (-h flag)
348  * and character set shifts.
349  */
350 void
351 flush_line(l)
352 	LINE *l;
353 {
354 	CHAR *c, *endc;
355 	int nchars, last_col, this_col;
356 
357 	last_col = 0;
358 	nchars = l->l_line_len;
359 
360 	if (l->l_needs_sort) {
361 		static CHAR *sorted;
362 		static int count_size, *count, i, save, sorted_size, tot;
363 
364 		/*
365 		 * Do an O(n) sort on l->l_line by column being careful to
366 		 * preserve the order of characters in the same column.
367 		 */
368 		if (l->l_lsize > sorted_size) {
369 			sorted_size = l->l_lsize;
370 			sorted = (CHAR *)xmalloc((void *)sorted,
371 			    (unsigned)sizeof(CHAR) * sorted_size);
372 		}
373 		if (l->l_max_col >= count_size) {
374 			count_size = l->l_max_col + 1;
375 			count = (int *)xmalloc((void *)count,
376 			    (unsigned)sizeof(int) * count_size);
377 		}
378 		memset((char *)count, 0, sizeof(int) * l->l_max_col + 1);
379 		for (i = nchars, c = l->l_line; --i >= 0; c++)
380 			count[c->c_column]++;
381 
382 		/*
383 		 * calculate running total (shifted down by 1) to use as
384 		 * indices into new line.
385 		 */
386 		for (tot = 0, i = 0; i <= l->l_max_col; i++) {
387 			save = count[i];
388 			count[i] = tot;
389 			tot += save;
390 		}
391 
392 		for (i = nchars, c = l->l_line; --i >= 0; c++)
393 			sorted[count[c->c_column]++] = *c;
394 		c = sorted;
395 	} else
396 		c = l->l_line;
397 	while (nchars > 0) {
398 		this_col = c->c_column;
399 		endc = c;
400 		do {
401 			++endc;
402 		} while (--nchars > 0 && this_col == endc->c_column);
403 
404 		/* if -b only print last character */
405 		if (no_backspaces)
406 			c = endc - 1;
407 
408 		if (this_col > last_col) {
409 			int nspace = this_col - last_col;
410 
411 			if (compress_spaces && nspace > 1) {
412 				int ntabs;
413 
414 				ntabs = this_col / 8 - last_col / 8;
415 				nspace -= ntabs * 8;
416 				while (--ntabs >= 0)
417 					PUTC('\t');
418 			}
419 			while (--nspace >= 0)
420 				PUTC(' ');
421 			last_col = this_col;
422 		}
423 		last_col++;
424 
425 		for (;;) {
426 			if (c->c_set != last_set) {
427 				switch (c->c_set) {
428 				case CS_NORMAL:
429 					PUTC('\017');
430 					break;
431 				case CS_ALTERNATE:
432 					PUTC('\016');
433 				}
434 				last_set = c->c_set;
435 			}
436 			PUTC(c->c_char);
437 			if (++c >= endc)
438 				break;
439 			PUTC('\b');
440 		}
441 	}
442 }
443 
444 #define	NALLOC 64
445 
446 static LINE *line_freelist;
447 
448 LINE *
449 alloc_line()
450 {
451 	LINE *l;
452 	int i;
453 
454 	if (!line_freelist) {
455 		l = (LINE *)xmalloc((void *)NULL, sizeof(LINE) * NALLOC);
456 		line_freelist = l;
457 		for (i = 1; i < NALLOC; i++, l++)
458 			l->l_next = l + 1;
459 		l->l_next = NULL;
460 	}
461 	l = line_freelist;
462 	line_freelist = l->l_next;
463 
464 	memset(l, 0, sizeof(LINE));
465 	return (l);
466 }
467 
468 void
469 free_line(l)
470 	LINE *l;
471 {
472 
473 	l->l_next = line_freelist;
474 	line_freelist = l;
475 }
476 
477 void *
478 xmalloc(p, size)
479 	void *p;
480 	size_t size;
481 {
482 
483 	if (!(p = (void *)realloc(p, size)))
484 		err(1, NULL);
485 	return (p);
486 }
487 
488 void
489 usage()
490 {
491 
492 	(void)fprintf(stderr, "usage: col [-bfx] [-l nline]\n");
493 	exit(1);
494 }
495 
496 void
497 wrerr()
498 {
499 
500 	(void)fprintf(stderr, "col: write error.\n");
501 	exit(1);
502 }
503 
504 void
505 dowarn(line)
506 	int line;
507 {
508 
509 	warnx("warning: can't back up %s",
510 		line < 0 ? "past first line" : "-- line already flushed");
511 }
512