col.c revision 102944 
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. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef lint
38static const char copyright[] =
39"@(#) Copyright (c) 1990, 1993, 1994\n\
40	The Regents of the University of California.  All rights reserved.\n";
41#endif
42
43#if 0
44#ifndef lint
45static char sccsid[] = "@(#)col.c	8.5 (Berkeley) 5/4/95";
46#endif
47#endif
48
49#include <sys/cdefs.h>
50__FBSDID("$FreeBSD: head/usr.bin/col/col.c 102944 2002-09-04 23:29:10Z dwmalone $");
51
52#include <ctype.h>
53#include <err.h>
54#include <string.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <unistd.h>
58#include <locale.h>
59
60#define	BS	'\b'		/* backspace */
61#define	TAB	'\t'		/* tab */
62#define	SPACE	' '		/* space */
63#define	NL	'\n'		/* newline */
64#define	CR	'\r'		/* carriage return */
65#define	ESC	'\033'		/* escape */
66#define	SI	'\017'		/* shift in to normal character set */
67#define	SO	'\016'		/* shift out to alternate character set */
68#define	VT	'\013'		/* vertical tab (aka reverse line feed) */
69#define	RLF	'\007'		/* ESC-07 reverse line feed */
70#define	RHLF	'\010'		/* ESC-010 reverse half-line feed */
71#define	FHLF	'\011'		/* ESC-011 forward half-line feed */
72
73/* build up at least this many lines before flushing them out */
74#define	BUFFER_MARGIN		32
75
76typedef char CSET;
77
78typedef struct char_str {
79#define	CS_NORMAL	1
80#define	CS_ALTERNATE	2
81	short		c_column;	/* column character is in */
82	CSET		c_set;		/* character set (currently only 2) */
83	char		c_char;		/* character in question */
84} CHAR;
85
86typedef struct line_str LINE;
87struct line_str {
88	CHAR	*l_line;		/* characters on the line */
89	LINE	*l_prev;		/* previous line */
90	LINE	*l_next;		/* next line */
91	int	l_lsize;		/* allocated sizeof l_line */
92	int	l_line_len;		/* strlen(l_line) */
93	int	l_needs_sort;		/* set if chars went in out of order */
94	int	l_max_col;		/* max column in the line */
95};
96
97LINE   *alloc_line(void);
98void	dowarn(int);
99void	flush_line(LINE *);
100void	flush_lines(int);
101void	flush_blanks(void);
102void	free_line(LINE *);
103void	usage(void);
104
105CSET	last_set;		/* char_set of last char printed */
106LINE   *lines;
107int	compress_spaces;	/* if doing space -> tab conversion */
108int	fine;			/* if `fine' resolution (half lines) */
109int	max_bufd_lines;		/* max # lines to keep in memory */
110int	nblank_lines;		/* # blanks after last flushed line */
111int	no_backspaces;		/* if not to output any backspaces */
112int	pass_unknown_seqs;	/* pass unknown control sequences */
113
114#define	PUTC(ch) \
115	do {					\
116		if (putchar(ch) == EOF)		\
117			errx(1, "write error");	\
118	} while (0)
119
120int
121main(int argc, char **argv)
122{
123	int ch;
124	CHAR *c;
125	CSET cur_set;			/* current character set */
126	LINE *l;			/* current line */
127	int extra_lines;		/* # of lines above first line */
128	int cur_col;			/* current column */
129	int cur_line;			/* line number of current position */
130	int max_line;			/* max value of cur_line */
131	int this_line;			/* line l points to */
132	int nflushd_lines;		/* number of lines that were flushed */
133	int adjust, opt, warned;
134
135	(void)setlocale(LC_CTYPE, "");
136
137	max_bufd_lines = 128;
138	compress_spaces = 1;		/* compress spaces into tabs */
139	while ((opt = getopt(argc, argv, "bfhl:px")) != -1)
140		switch (opt) {
141		case 'b':		/* do not output backspaces */
142			no_backspaces = 1;
143			break;
144		case 'f':		/* allow half forward line feeds */
145			fine = 1;
146			break;
147		case 'h':		/* compress spaces into tabs */
148			compress_spaces = 1;
149			break;
150		case 'l':		/* buffered line count */
151			if ((max_bufd_lines = atoi(optarg)) <= 0)
152				errx(1, "bad -l argument %s", optarg);
153			break;
154		case 'p':		/* pass unknown control sequences */
155			pass_unknown_seqs = 1;
156			break;
157		case 'x':		/* do not compress spaces into tabs */
158			compress_spaces = 0;
159			break;
160		case '?':
161		default:
162			usage();
163		}
164
165	if (optind != argc)
166		usage();
167
168	/* this value is in half lines */
169	max_bufd_lines *= 2;
170
171	adjust = cur_col = extra_lines = warned = 0;
172	cur_line = max_line = nflushd_lines = this_line = 0;
173	cur_set = last_set = CS_NORMAL;
174	lines = l = alloc_line();
175
176	while ((ch = getchar()) != EOF) {
177		if (!isgraph(ch)) {
178			switch (ch) {
179			case BS:		/* can't go back further */
180				if (cur_col == 0)
181					continue;
182				--cur_col;
183				continue;
184			case CR:
185				cur_col = 0;
186				continue;
187			case ESC:		/* just ignore EOF */
188				switch(getchar()) {
189				case RLF:
190					cur_line -= 2;
191					break;
192				case RHLF:
193					cur_line--;
194					break;
195				case FHLF:
196					cur_line++;
197					if (cur_line > max_line)
198						max_line = cur_line;
199				}
200				continue;
201			case NL:
202				cur_line += 2;
203				if (cur_line > max_line)
204					max_line = cur_line;
205				cur_col = 0;
206				continue;
207			case SPACE:
208				++cur_col;
209				continue;
210			case SI:
211				cur_set = CS_NORMAL;
212				continue;
213			case SO:
214				cur_set = CS_ALTERNATE;
215				continue;
216			case TAB:		/* adjust column */
217				cur_col |= 7;
218				++cur_col;
219				continue;
220			case VT:
221				cur_line -= 2;
222				continue;
223			}
224			if (!pass_unknown_seqs)
225				continue;
226		}
227
228		/* Must stuff ch in a line - are we at the right one? */
229		if (cur_line != this_line - adjust) {
230			LINE *lnew;
231			int nmove;
232
233			adjust = 0;
234			nmove = cur_line - this_line;
235			if (!fine) {
236				/* round up to next line */
237				if (cur_line & 1) {
238					adjust = 1;
239					nmove++;
240				}
241			}
242			if (nmove < 0) {
243				for (; nmove < 0 && l->l_prev; nmove++)
244					l = l->l_prev;
245				if (nmove) {
246					if (nflushd_lines == 0) {
247						/*
248						 * Allow backup past first
249						 * line if nothing has been
250						 * flushed yet.
251						 */
252						for (; nmove < 0; nmove++) {
253							lnew = alloc_line();
254							l->l_prev = lnew;
255							lnew->l_next = l;
256							l = lines = lnew;
257							extra_lines++;
258						}
259					} else {
260						if (!warned++)
261							dowarn(cur_line);
262						cur_line -= nmove;
263					}
264				}
265			} else {
266				/* may need to allocate here */
267				for (; nmove > 0 && l->l_next; nmove--)
268					l = l->l_next;
269				for (; nmove > 0; nmove--) {
270					lnew = alloc_line();
271					lnew->l_prev = l;
272					l->l_next = lnew;
273					l = lnew;
274				}
275			}
276			this_line = cur_line + adjust;
277			nmove = this_line - nflushd_lines;
278			if (nmove >= max_bufd_lines + BUFFER_MARGIN) {
279				nflushd_lines += nmove - max_bufd_lines;
280				flush_lines(nmove - max_bufd_lines);
281			}
282		}
283		/* grow line's buffer? */
284		if (l->l_line_len + 1 >= l->l_lsize) {
285			int need;
286
287			need = l->l_lsize ? l->l_lsize * 2 : 90;
288			if ((l->l_line = realloc(l->l_line,
289			    (unsigned)need * sizeof(CHAR))) == NULL)
290				err(1, (char *)NULL);
291			l->l_lsize = need;
292		}
293		c = &l->l_line[l->l_line_len++];
294		c->c_char = ch;
295		c->c_set = cur_set;
296		c->c_column = cur_col;
297		/*
298		 * If things are put in out of order, they will need sorting
299		 * when it is flushed.
300		 */
301		if (cur_col < l->l_max_col)
302			l->l_needs_sort = 1;
303		else
304			l->l_max_col = cur_col;
305		cur_col++;
306	}
307	if (max_line == 0)
308		exit(0);	/* no lines, so just exit */
309
310	/* goto the last line that had a character on it */
311	for (; l->l_next; l = l->l_next)
312		this_line++;
313	flush_lines(this_line - nflushd_lines + extra_lines + 1);
314
315	/* make sure we leave things in a sane state */
316	if (last_set != CS_NORMAL)
317		PUTC('\017');
318
319	/* flush out the last few blank lines */
320	nblank_lines = max_line - this_line;
321	if (max_line & 1)
322		nblank_lines++;
323	else if (!nblank_lines)
324		/* missing a \n on the last line? */
325		nblank_lines = 2;
326	flush_blanks();
327	exit(0);
328}
329
330void
331flush_lines(int nflush)
332{
333	LINE *l;
334
335	while (--nflush >= 0) {
336		l = lines;
337		lines = l->l_next;
338		if (l->l_line) {
339			flush_blanks();
340			flush_line(l);
341		}
342		nblank_lines++;
343		if (l->l_line)
344			(void)free(l->l_line);
345		free_line(l);
346	}
347	if (lines)
348		lines->l_prev = NULL;
349}
350
351/*
352 * Print a number of newline/half newlines.  If fine flag is set, nblank_lines
353 * is the number of half line feeds, otherwise it is the number of whole line
354 * feeds.
355 */
356void
357flush_blanks(void)
358{
359	int half, i, nb;
360
361	half = 0;
362	nb = nblank_lines;
363	if (nb & 1) {
364		if (fine)
365			half = 1;
366		else
367			nb++;
368	}
369	nb /= 2;
370	for (i = nb; --i >= 0;)
371		PUTC('\n');
372	if (half) {
373		PUTC('\033');
374		PUTC('9');
375		if (!nb)
376			PUTC('\r');
377	}
378	nblank_lines = 0;
379}
380
381/*
382 * Write a line to stdout taking care of space to tab conversion (-h flag)
383 * and character set shifts.
384 */
385void
386flush_line(LINE *l)
387{
388	CHAR *c, *endc;
389	int nchars, last_col, this_col;
390
391	last_col = 0;
392	nchars = l->l_line_len;
393
394	if (l->l_needs_sort) {
395		static CHAR *sorted;
396		static int count_size, *count, i, save, sorted_size, tot;
397
398		/*
399		 * Do an O(n) sort on l->l_line by column being careful to
400		 * preserve the order of characters in the same column.
401		 */
402		if (l->l_lsize > sorted_size) {
403			sorted_size = l->l_lsize;
404			if ((sorted = realloc(sorted,
405			    (unsigned)sizeof(CHAR) * sorted_size)) == NULL)
406				err(1, (char *)NULL);
407		}
408		if (l->l_max_col >= count_size) {
409			count_size = l->l_max_col + 1;
410			if ((count = realloc(count,
411			    (unsigned)sizeof(int) * count_size)) == NULL)
412				err(1, (char *)NULL);
413		}
414		memset(count, 0, sizeof(int) * l->l_max_col + 1);
415		for (i = nchars, c = l->l_line; --i >= 0; c++)
416			count[c->c_column]++;
417
418		/*
419		 * calculate running total (shifted down by 1) to use as
420		 * indices into new line.
421		 */
422		for (tot = 0, i = 0; i <= l->l_max_col; i++) {
423			save = count[i];
424			count[i] = tot;
425			tot += save;
426		}
427
428		for (i = nchars, c = l->l_line; --i >= 0; c++)
429			sorted[count[c->c_column]++] = *c;
430		c = sorted;
431	} else
432		c = l->l_line;
433	while (nchars > 0) {
434		this_col = c->c_column;
435		endc = c;
436		do {
437			++endc;
438		} while (--nchars > 0 && this_col == endc->c_column);
439
440		/* if -b only print last character */
441		if (no_backspaces)
442			c = endc - 1;
443
444		if (this_col > last_col) {
445			int nspace = this_col - last_col;
446
447			if (compress_spaces && nspace > 1) {
448				while (1) {
449					int tab_col, tab_size;;
450
451					tab_col = (last_col + 8) & ~7;
452					if (tab_col > this_col)
453						break;
454					tab_size = tab_col - last_col;
455					if (tab_size == 1)
456						PUTC(' ');
457					else
458						PUTC('\t');
459					nspace -= tab_size;
460					last_col = tab_col;
461				}
462			}
463			while (--nspace >= 0)
464				PUTC(' ');
465			last_col = this_col;
466		}
467		last_col++;
468
469		for (;;) {
470			if (c->c_set != last_set) {
471				switch (c->c_set) {
472				case CS_NORMAL:
473					PUTC('\017');
474					break;
475				case CS_ALTERNATE:
476					PUTC('\016');
477				}
478				last_set = c->c_set;
479			}
480			PUTC(c->c_char);
481			if (++c >= endc)
482				break;
483			PUTC('\b');
484		}
485	}
486}
487
488#define	NALLOC 64
489
490static LINE *line_freelist;
491
492LINE *
493alloc_line(void)
494{
495	LINE *l;
496	int i;
497
498	if (!line_freelist) {
499		if ((l = realloc(NULL, sizeof(LINE) * NALLOC)) == NULL)
500			err(1, (char *)NULL);
501		line_freelist = l;
502		for (i = 1; i < NALLOC; i++, l++)
503			l->l_next = l + 1;
504		l->l_next = NULL;
505	}
506	l = line_freelist;
507	line_freelist = l->l_next;
508
509	memset(l, 0, sizeof(LINE));
510	return (l);
511}
512
513void
514free_line(LINE *l)
515{
516
517	l->l_next = line_freelist;
518	line_freelist = l;
519}
520
521void
522usage(void)
523{
524
525	(void)fprintf(stderr, "usage: col [-bfhpx] [-l nline]\n");
526	exit(1);
527}
528
529void
530dowarn(int line)
531{
532
533	warnx("warning: can't back up %s",
534		line < 0 ? "past first line" : "-- line already flushed");
535}
536