expand.c revision 1.9 
1/*	$NetBSD: expand.c,v 1.9 2003/08/07 11:13:39 agc Exp $	*/
2
3/*
4 * Copyright (c) 1980, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34__COPYRIGHT("@(#) Copyright (c) 1980, 1993\n\
35	The Regents of the University of California.  All rights reserved.\n");
36#endif /* not lint */
37
38#ifndef lint
39#if 0
40static char sccsid[] = "@(#)expand.c	8.1 (Berkeley) 6/9/93";
41#endif
42__RCSID("$NetBSD: expand.c,v 1.9 2003/08/07 11:13:39 agc Exp $");
43#endif /* not lint */
44
45#include <stdio.h>
46#include <stdlib.h>
47#include <ctype.h>
48#include <unistd.h>
49
50/*
51 * expand - expand tabs to equivalent spaces
52 */
53int	nstops;
54int	tabstops[100];
55
56static	void	getstops __P((char *));
57	int	main __P((int, char **));
58static	void	usage __P((void));
59
60int
61main(argc, argv)
62	int argc;
63	char *argv[];
64{
65	int c, column;
66	int n;
67
68	/* handle obsolete syntax */
69	while (argc > 1 &&
70	    argv[1][0] == '-' && isdigit((unsigned char)argv[1][1])) {
71		getstops(&argv[1][1]);
72		argc--; argv++;
73	}
74
75	while ((c = getopt (argc, argv, "t:")) != -1) {
76		switch (c) {
77		case 't':
78			getstops(optarg);
79			break;
80		case '?':
81		default:
82			usage();
83			/* NOTREACHED */
84		}
85	}
86	argc -= optind;
87	argv += optind;
88
89	do {
90		if (argc > 0) {
91			if (freopen(argv[0], "r", stdin) == NULL) {
92				perror(argv[0]);
93				exit(EXIT_FAILURE);
94			}
95			argc--, argv++;
96		}
97		column = 0;
98		while ((c = getchar()) != EOF) {
99			switch (c) {
100			case '\t':
101				if (nstops == 0) {
102					do {
103						putchar(' ');
104						column++;
105					} while (column & 07);
106					continue;
107				}
108				if (nstops == 1) {
109					do {
110						putchar(' ');
111						column++;
112					} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
113					continue;
114				}
115				for (n = 0; n < nstops; n++)
116					if (tabstops[n] > column)
117						break;
118				if (n == nstops) {
119					putchar(' ');
120					column++;
121					continue;
122				}
123				while (column < tabstops[n]) {
124					putchar(' ');
125					column++;
126				}
127				continue;
128
129			case '\b':
130				if (column)
131					column--;
132				putchar('\b');
133				continue;
134
135			default:
136				putchar(c);
137				column++;
138				continue;
139
140			case '\n':
141				putchar(c);
142				column = 0;
143				continue;
144			}
145		}
146	} while (argc > 0);
147	exit(EXIT_SUCCESS);
148	/* NOTREACHED */
149}
150
151static void
152getstops(cp)
153	char *cp;
154{
155	int i;
156
157	nstops = 0;
158	for (;;) {
159		i = 0;
160		while (*cp >= '0' && *cp <= '9')
161			i = i * 10 + *cp++ - '0';
162		if (i <= 0 || i > 256) {
163bad:
164			fprintf(stderr, "Bad tab stop spec\n");
165			exit(EXIT_FAILURE);
166		}
167		if (nstops > 0 && i <= tabstops[nstops-1])
168			goto bad;
169		tabstops[nstops++] = i;
170		if (*cp == 0)
171			break;
172		if (*cp != ',' && *cp != ' ')
173			goto bad;
174		cp++;
175	}
176}
177
178static void
179usage()
180{
181
182	(void)fprintf(stderr, "usage: expand [-t tablist] [file ...]\n");
183	exit(EXIT_FAILURE);
184}
185