unexpand.c revision 98251 
1/*-
2 * Copyright (c) 1980, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35
36__FBSDID("$FreeBSD: head/usr.bin/unexpand/unexpand.c 98251 2002-06-15 10:16:39Z tjr $");
37
38#ifndef lint
39static const char copyright[] =
40"@(#) Copyright (c) 1980, 1993\n\
41	The Regents of the University of California.  All rights reserved.\n";
42#endif
43
44#ifndef lint
45static const char sccsid[] = "@(#)unexpand.c	8.1 (Berkeley) 6/6/93";
46#endif
47
48/*
49 * unexpand - put tabs into a file replacing blanks
50 */
51#include <ctype.h>
52#include <err.h>
53#include <limits.h>
54#include <locale.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <unistd.h>
59
60int	all;
61int	nstops;
62int	tabstops[100];
63
64static void getstops(const char *);
65static void usage(void);
66static void tabify(void);
67
68int
69main(argc, argv)
70	int argc;
71	char *argv[];
72{
73	int ch, failed;
74	char *filename;
75
76	setlocale(LC_CTYPE, "");
77
78	nstops = 1;
79	tabstops[0] = 8;
80	while ((ch = getopt(argc, argv, "at:")) != -1) {
81		switch (ch) {
82		case 'a':	/* Un-expand all spaces, not just leading. */
83			all = 1;
84			break;
85		case 't':	/* Specify tab list, implies -a. */
86			getstops(optarg);
87			all = 1;
88			break;
89		default:
90			usage();
91			/*NOTREACHED*/
92		}
93	}
94	argc -= optind;
95	argv += optind;
96
97	failed = 0;
98	if (argc == 0)
99		tabify();
100	else {
101		while ((filename = *argv++) != NULL) {
102			if (freopen(filename, "r", stdin) == NULL) {
103				warn("%s", filename);
104				failed++;
105			} else
106				tabify();
107		}
108	}
109	exit(failed != 0);
110}
111
112static void
113usage()
114{
115	fprintf(stderr, "usage: unexpand [-a] [-t tablist] [file ...]\n");
116	exit(1);
117}
118
119static void
120tabify()
121{
122	int ch, dcol, doneline, limit, n, ocol;
123
124	limit = nstops == 1 ? INT_MAX : tabstops[nstops - 1] - 1;
125
126	doneline = ocol = dcol = 0;
127	while ((ch = getchar()) != EOF) {
128		if (ch == ' ' && !doneline) {
129			if (++dcol >= limit)
130				doneline = 1;
131			continue;
132		} else if (ch == '\t') {
133			if (nstops == 1) {
134				dcol = (1 + dcol / tabstops[0]) *
135				    tabstops[0];
136				continue;
137			} else {
138				for (n = 0; tabstops[n] - 1 < dcol &&
139				    n < nstops; n++)
140					;
141				if (n < nstops - 1 && tabstops[n] - 1 < limit) {
142					dcol = tabstops[n];
143					continue;
144				}
145				doneline = 1;
146			}
147		}
148
149		/* Output maximal number of tabs. */
150		if (nstops == 1) {
151			while (((ocol + tabstops[0]) / tabstops[0])
152			    <= (dcol / tabstops[0])) {
153				if (dcol - ocol < 2)
154					break;
155				putchar('\t');
156				ocol = (1 + ocol / tabstops[0]) *
157				    tabstops[0];
158			}
159		} else {
160			for (n = 0; tabstops[n] - 1 < ocol && n < nstops; n++)
161				;
162			while (ocol < dcol && n < nstops && ocol < limit) {
163				putchar('\t');
164				ocol = tabstops[n++];
165			}
166		}
167
168		/* Then spaces. */
169		while (ocol < dcol && ocol < limit) {
170			putchar(' ');
171			ocol++;
172		}
173
174		if (ch == '\b') {
175			putchar('\b');
176			if (ocol > 0)
177				ocol--, dcol--;
178		} else if (ch == '\n') {
179			putchar('\n');
180			doneline = ocol = dcol = 0;
181		} else if (ch != ' ' || dcol > limit) {
182			putchar(ch);
183			if (isprint(ch))
184				ocol++, dcol++;
185		}
186
187		/*
188		 * Only processing leading blanks or we've gone past the
189		 * last tab stop. Emit remainder of this line unchanged.
190		 */
191		if (!all || dcol >= limit) {
192			while ((ch = getchar()) != '\n' && ch != EOF)
193				putchar(ch);
194			if (ch == '\n')
195				putchar('\n');
196			doneline = ocol = dcol = 0;
197		}
198	}
199}
200
201static void
202getstops(cp)
203	const char *cp;
204{
205	int i;
206
207	nstops = 0;
208	for (;;) {
209		i = 0;
210		while (*cp >= '0' && *cp <= '9')
211			i = i * 10 + *cp++ - '0';
212		if (i <= 0)
213			errx(1, "bad tab stop spec");
214		if (nstops > 0 && i <= tabstops[nstops-1])
215			errx(1, "bad tab stop spec");
216		if (nstops == sizeof(tabstops) / sizeof(*tabstops))
217			errx(1, "too many tab stops");
218		tabstops[nstops++] = i;
219		if (*cp == 0)
220			break;
221		if (*cp != ',' && !isblank((unsigned char)*cp))
222			errx(1, "bad tab stop spec");
223		cp++;
224	}
225}
226