expand.c revision 58606 
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#ifndef lint
35static const char copyright[] =
36"@(#) Copyright (c) 1980, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41#if 0
42static char sccsid[] = "@(#)expand.c	8.1 (Berkeley) 6/9/93";
43#endif
44static const char rcsid[] =
45  "$FreeBSD: head/usr.bin/expand/expand.c 58606 2000-03-26 14:28:31Z charnier $";
46#endif /* not lint */
47
48#include <ctype.h>
49#include <err.h>
50#include <stdio.h>
51#include <unistd.h>
52
53/*
54 * expand - expand tabs to equivalent spaces
55 */
56int	nstops;
57int	tabstops[100];
58
59static void getstops __P((char *));
60static void usage __P((void));
61
62int
63main(argc, argv)
64	int argc;
65	char *argv[];
66{
67	register int c, column;
68	register int n;
69
70	/* handle obsolete syntax */
71	while (argc > 1 && argv[1][0] == '-' && isdigit(argv[1][1])) {
72		getstops(&argv[1][1]);
73		argc--; argv++;
74	}
75
76	while ((c = getopt (argc, argv, "t:")) != -1) {
77		switch (c) {
78		case 't':
79			getstops(optarg);
80			break;
81		case '?':
82		default:
83			usage();
84			/* NOTREACHED */
85		}
86	}
87	argc -= optind;
88	argv += optind;
89
90	do {
91		if (argc > 0) {
92			if (freopen(argv[0], "r", stdin) == NULL)
93				errx(1, "%s", argv[0]);
94			argc--, argv++;
95		}
96		column = 0;
97		while ((c = getchar()) != EOF) {
98			switch (c) {
99			case '\t':
100				if (nstops == 0) {
101					do {
102						putchar(' ');
103						column++;
104					} while (column & 07);
105					continue;
106				}
107				if (nstops == 1) {
108					do {
109						putchar(' ');
110						column++;
111					} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
112					continue;
113				}
114				for (n = 0; n < nstops; n++)
115					if (tabstops[n] > column)
116						break;
117				if (n == nstops) {
118					putchar(' ');
119					column++;
120					continue;
121				}
122				while (column < tabstops[n]) {
123					putchar(' ');
124					column++;
125				}
126				continue;
127
128			case '\b':
129				if (column)
130					column--;
131				putchar('\b');
132				continue;
133
134			default:
135				putchar(c);
136				column++;
137				continue;
138
139			case '\n':
140				putchar(c);
141				column = 0;
142				continue;
143			}
144		}
145	} while (argc > 0);
146	exit(0);
147}
148
149static void
150getstops(cp)
151	register char *cp;
152{
153	register int i;
154
155	nstops = 0;
156	for (;;) {
157		i = 0;
158		while (*cp >= '0' && *cp <= '9')
159			i = i * 10 + *cp++ - '0';
160		if (i <= 0 || i > 256)
161			errx(1, "bad tab stop spec");
162		if (nstops > 0 && i <= tabstops[nstops-1])
163			errx(1, "bad tab stop spec");
164		tabstops[nstops++] = i;
165		if (*cp == 0)
166			break;
167		if (*cp != ',' && *cp != ' ')
168			errx(1, "bad tab stop spec");
169		cp++;
170	}
171}
172
173static void
174usage()
175{
176	(void)fprintf (stderr, "usage: expand [-t tablist] [file ...]\n");
177	exit(1);
178}
179