expand.c revision 33016 
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 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#else
44static const char rcsid[] =
45	"$Id: expand.c,v 1.2 1997/07/01 06:34:31 charnier Exp $";
46#endif
47#endif /* not lint */
48
49#include <ctype.h>
50#include <stdio.h>
51#include <stdlib.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 *));
61static void usage __P((void));
62
63int
64main(argc, argv)
65	int argc;
66	char *argv[];
67{
68	register int c, column;
69	register int n;
70
71	/* handle obsolete syntax */
72	while (argc > 1 && argv[1][0] == '-' && isdigit(argv[1][1])) {
73		getstops(&argv[1][1]);
74		argc--; argv++;
75	}
76
77	while ((c = getopt (argc, argv, "t:")) != -1) {
78		switch (c) {
79		case 't':
80			getstops(optarg);
81			break;
82		case '?':
83		default:
84			usage();
85			/* NOTREACHED */
86		}
87	}
88	argc -= optind;
89	argv += optind;
90
91	do {
92		if (argc > 0) {
93			if (freopen(argv[0], "r", stdin) == NULL) {
94				perror(argv[0]);
95				exit(1);
96			}
97			argc--, argv++;
98		}
99		column = 0;
100		while ((c = getchar()) != EOF) {
101			switch (c) {
102			case '\t':
103				if (nstops == 0) {
104					do {
105						putchar(' ');
106						column++;
107					} while (column & 07);
108					continue;
109				}
110				if (nstops == 1) {
111					do {
112						putchar(' ');
113						column++;
114					} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
115					continue;
116				}
117				for (n = 0; n < nstops; n++)
118					if (tabstops[n] > column)
119						break;
120				if (n == nstops) {
121					putchar(' ');
122					column++;
123					continue;
124				}
125				while (column < tabstops[n]) {
126					putchar(' ');
127					column++;
128				}
129				continue;
130
131			case '\b':
132				if (column)
133					column--;
134				putchar('\b');
135				continue;
136
137			default:
138				putchar(c);
139				column++;
140				continue;
141
142			case '\n':
143				putchar(c);
144				column = 0;
145				continue;
146			}
147		}
148	} while (argc > 0);
149	exit(0);
150}
151
152static void
153getstops(cp)
154	register char *cp;
155{
156	register int i;
157
158	nstops = 0;
159	for (;;) {
160		i = 0;
161		while (*cp >= '0' && *cp <= '9')
162			i = i * 10 + *cp++ - '0';
163		if (i <= 0 || i > 256) {
164bad:
165			fprintf(stderr, "Bad tab stop spec\n");
166			exit(1);
167		}
168		if (nstops > 0 && i <= tabstops[nstops-1])
169			goto bad;
170		tabstops[nstops++] = i;
171		if (*cp == 0)
172			break;
173		if (*cp != ',' && *cp != ' ')
174			goto bad;
175		cp++;
176	}
177}
178
179static void
180usage()
181{
182	(void)fprintf (stderr, "usage: expand [-t tablist] [file ...]\n");
183	exit(1);
184}
185