unexpand.c revision 92922 
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#include <sys/cdefs.h>
35
36__FBSDID("$FreeBSD: head/usr.bin/unexpand/unexpand.c 92922 2002-03-22 01:42:45Z imp $");
37
38#ifndef lint
39static const char copyright[] =
40"@(#) Copyright (c) 1980, 1993\n\
41	The Regents of the University of California.  All rights reserved.\n";
42#endif
43
44#ifndef lint
45static const char sccsid[] = "@(#)unexpand.c	8.1 (Berkeley) 6/6/93";
46#endif
47
48/*
49 * unexpand - put tabs into a file replacing blanks
50 */
51#include <err.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55
56char	genbuf[BUFSIZ];
57char	linebuf[BUFSIZ];
58int	all;
59
60static void usage(void);
61void tabify(char);
62
63int
64main(argc, argv)
65	int argc;
66	char *argv[];
67{
68	register char *cp;
69
70	argc--, argv++;
71	if (argc > 0 && argv[0][0] == '-') {
72		if (strcmp(argv[0], "-a") != 0)
73			usage();
74		all++;
75		argc--, argv++;
76	}
77	do {
78		if (argc > 0) {
79			if (freopen(argv[0], "r", stdin) == NULL)
80				err(1, "%s", argv[0]);
81			argc--, argv++;
82		}
83		while (fgets(genbuf, BUFSIZ, stdin) != NULL) {
84			for (cp = linebuf; *cp; cp++)
85				continue;
86			if (cp > linebuf)
87				cp[-1] = 0;
88			tabify(all);
89			printf("%s", linebuf);
90		}
91	} while (argc > 0);
92	exit(0);
93}
94
95static void
96usage()
97{
98	fprintf(stderr, "usage: unexpand [-a] file ...\n");
99	exit(1);
100}
101
102void
103tabify(c)
104	char c;
105{
106	register char *cp, *dp;
107	register int dcol;
108	int ocol;
109
110	ocol = 0;
111	dcol = 0;
112	cp = genbuf, dp = linebuf;
113	for (;;) {
114		switch (*cp) {
115
116		case ' ':
117			dcol++;
118			break;
119
120		case '\t':
121			dcol += 8;
122			dcol &= ~07;
123			break;
124
125		default:
126			while (((ocol + 8) &~ 07) <= dcol) {
127				if (ocol + 1 == dcol)
128					break;
129				*dp++ = '\t';
130				ocol += 8;
131				ocol &= ~07;
132			}
133			while (ocol < dcol) {
134				*dp++ = ' ';
135				ocol++;
136			}
137			if (*cp == 0 || c == 0) {
138				strcpy(dp, cp);
139				return;
140			}
141			*dp++ = *cp;
142			ocol++, dcol++;
143		}
144		cp++;
145	}
146}
147