expand.c revision 1.7 
1/*	$NetBSD: expand.c,v 1.7 1998/11/06 23:10:40 christos 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 1.7 1998/11/06 23:10:40 christos 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 && argv[1][0] && isdigit((unsigned char)argv[1][1])) {
74		getstops(&argv[1][1]);
75		argc--; argv++;
76	}
77
78	while ((c = getopt (argc, argv, "t:")) != -1) {
79		switch (c) {
80		case 't':
81			getstops(optarg);
82			break;
83		case '?':
84		default:
85			usage();
86			/* NOTREACHED */
87		}
88	}
89	argc -= optind;
90	argv += optind;
91
92	do {
93		if (argc > 0) {
94			if (freopen(argv[0], "r", stdin) == NULL) {
95				perror(argv[0]);
96				exit(1);
97			}
98			argc--, argv++;
99		}
100		column = 0;
101		while ((c = getchar()) != EOF) {
102			switch (c) {
103			case '\t':
104				if (nstops == 0) {
105					do {
106						putchar(' ');
107						column++;
108					} while (column & 07);
109					continue;
110				}
111				if (nstops == 1) {
112					do {
113						putchar(' ');
114						column++;
115					} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
116					continue;
117				}
118				for (n = 0; n < nstops; n++)
119					if (tabstops[n] > column)
120						break;
121				if (n == nstops) {
122					putchar(' ');
123					column++;
124					continue;
125				}
126				while (column < tabstops[n]) {
127					putchar(' ');
128					column++;
129				}
130				continue;
131
132			case '\b':
133				if (column)
134					column--;
135				putchar('\b');
136				continue;
137
138			default:
139				putchar(c);
140				column++;
141				continue;
142
143			case '\n':
144				putchar(c);
145				column = 0;
146				continue;
147			}
148		}
149	} while (argc > 0);
150	exit(0);
151}
152
153static void
154getstops(cp)
155	char *cp;
156{
157	int i;
158
159	nstops = 0;
160	for (;;) {
161		i = 0;
162		while (*cp >= '0' && *cp <= '9')
163			i = i * 10 + *cp++ - '0';
164		if (i <= 0 || i > 256) {
165bad:
166			fprintf(stderr, "Bad tab stop spec\n");
167			exit(1);
168		}
169		if (nstops > 0 && i <= tabstops[nstops-1])
170			goto bad;
171		tabstops[nstops++] = i;
172		if (*cp == 0)
173			break;
174		if (*cp != ',' && *cp != ' ')
175			goto bad;
176		cp++;
177	}
178}
179
180static void
181usage()
182{
183	(void)fprintf (stderr, "usage: expand [-t tablist] [file ...]\n");
184	exit(1);
185}
186