expand.c revision 1.8 
1/*	$NetBSD: expand.c,v 1.8 1999/02/10 16:15:31 kleink 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. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <sys/cdefs.h>
37#ifndef lint
38__COPYRIGHT("@(#) Copyright (c) 1980, 1993\n\
39	The Regents of the University of California.  All rights reserved.\n");
40#endif /* not lint */
41
42#ifndef lint
43#if 0
44static char sccsid[] = "@(#)expand.c	8.1 (Berkeley) 6/9/93";
45#endif
46__RCSID("$NetBSD: expand.c,v 1.8 1999/02/10 16:15:31 kleink Exp $");
47#endif /* not lint */
48
49#include <stdio.h>
50#include <stdlib.h>
51#include <ctype.h>
52#include <unistd.h>
53
54/*
55 * expand - expand tabs to equivalent spaces
56 */
57int	nstops;
58int	tabstops[100];
59
60static	void	getstops __P((char *));
61	int	main __P((int, char **));
62static	void	usage __P((void));
63
64int
65main(argc, argv)
66	int argc;
67	char *argv[];
68{
69	int c, column;
70	int n;
71
72	/* handle obsolete syntax */
73	while (argc > 1 &&
74	    argv[1][0] == '-' && isdigit((unsigned char)argv[1][1])) {
75		getstops(&argv[1][1]);
76		argc--; argv++;
77	}
78
79	while ((c = getopt (argc, argv, "t:")) != -1) {
80		switch (c) {
81		case 't':
82			getstops(optarg);
83			break;
84		case '?':
85		default:
86			usage();
87			/* NOTREACHED */
88		}
89	}
90	argc -= optind;
91	argv += optind;
92
93	do {
94		if (argc > 0) {
95			if (freopen(argv[0], "r", stdin) == NULL) {
96				perror(argv[0]);
97				exit(EXIT_FAILURE);
98			}
99			argc--, argv++;
100		}
101		column = 0;
102		while ((c = getchar()) != EOF) {
103			switch (c) {
104			case '\t':
105				if (nstops == 0) {
106					do {
107						putchar(' ');
108						column++;
109					} while (column & 07);
110					continue;
111				}
112				if (nstops == 1) {
113					do {
114						putchar(' ');
115						column++;
116					} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
117					continue;
118				}
119				for (n = 0; n < nstops; n++)
120					if (tabstops[n] > column)
121						break;
122				if (n == nstops) {
123					putchar(' ');
124					column++;
125					continue;
126				}
127				while (column < tabstops[n]) {
128					putchar(' ');
129					column++;
130				}
131				continue;
132
133			case '\b':
134				if (column)
135					column--;
136				putchar('\b');
137				continue;
138
139			default:
140				putchar(c);
141				column++;
142				continue;
143
144			case '\n':
145				putchar(c);
146				column = 0;
147				continue;
148			}
149		}
150	} while (argc > 0);
151	exit(EXIT_SUCCESS);
152	/* NOTREACHED */
153}
154
155static void
156getstops(cp)
157	char *cp;
158{
159	int i;
160
161	nstops = 0;
162	for (;;) {
163		i = 0;
164		while (*cp >= '0' && *cp <= '9')
165			i = i * 10 + *cp++ - '0';
166		if (i <= 0 || i > 256) {
167bad:
168			fprintf(stderr, "Bad tab stop spec\n");
169			exit(EXIT_FAILURE);
170		}
171		if (nstops > 0 && i <= tabstops[nstops-1])
172			goto bad;
173		tabstops[nstops++] = i;
174		if (*cp == 0)
175			break;
176		if (*cp != ',' && *cp != ' ')
177			goto bad;
178		cp++;
179	}
180}
181
182static void
183usage()
184{
185
186	(void)fprintf(stderr, "usage: expand [-t tablist] [file ...]\n");
187	exit(EXIT_FAILURE);
188}
189