1/*	$NetBSD: expand.c,v 1.14 2016/09/05 00:40:28 sevan 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\
35 The Regents of the University of California.  All rights reserved.");
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 1.14 2016/09/05 00:40:28 sevan Exp $");
43#endif /* not lint */
44
45#include <stdio.h>
46#include <stdlib.h>
47#include <ctype.h>
48#include <unistd.h>
49#include <err.h>
50
51/*
52 * expand - expand tabs to equivalent spaces
53 */
54size_t	nstops;
55size_t	tabstops[100];
56
57static	void	getstops(const char *);
58static	void	usage(void) __dead;
59
60int
61main(int argc, char *argv[])
62{
63	int c;
64	size_t n, column;
65
66	setprogname(argv[0]);
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				err(EXIT_FAILURE, "Cannot open `%s'", argv[0]);
93			argc--, argv++;
94		}
95		column = 0;
96		while ((c = getchar()) != EOF) {
97			switch (c) {
98			case '\t':
99				if (nstops == 0) {
100					do {
101						putchar(' ');
102						column++;
103					} while (column & 07);
104					continue;
105				}
106				if (nstops == 1) {
107					do {
108						putchar(' ');
109						column++;
110					} while (((column - 1) % tabstops[0])
111					    != (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	return EXIT_SUCCESS;
147}
148
149static void
150getstops(const char *spec)
151{
152	int i;
153	const char *cp = spec;
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(EXIT_FAILURE, "Too large tab stop spec `%d'", i);
162		if (nstops > 0 && (size_t)i <= tabstops[nstops-1])
163			errx(EXIT_FAILURE, "Out of order tabstop spec `%d'", i);
164		if (nstops == sizeof(tabstops) / sizeof(tabstops[0]) - 1)
165			errx(EXIT_FAILURE, "Too many tabstops");
166		tabstops[nstops++] = i;
167		if (*cp == '\0')
168			break;
169		if (*cp != ',' && *cp != ' ')
170			errx(EXIT_FAILURE, "Illegal tab stop spec `%s'", spec);
171		cp++;
172	}
173}
174
175static void
176usage(void)
177{
178
179	(void)fprintf(stderr, "Usage: %s [-t tablist] [file ...]\n",
180	    getprogname());
181	exit(EXIT_FAILURE);
182}
183