unexpand.c revision 28789 
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 const 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[] = "@(#)unexpand.c	8.1 (Berkeley) 6/6/93";
43#endif
44static const char rcsid[] =
45	"$Id: unexpand.c,v 1.2 1997/08/20 11:05:28 charnier Exp $";
46#endif /* not lint */
47
48/*
49 * unexpand - put tabs into a file replacing blanks
50 */
51#include <err.h>
52#include <stdio.h>
53
54char	genbuf[BUFSIZ];
55char	linebuf[BUFSIZ];
56int	all;
57
58static void usage __P((void));
59void tabify __P((char));
60
61int
62main(argc, argv)
63	int argc;
64	char *argv[];
65{
66	register char *cp;
67
68	argc--, argv++;
69	if (argc > 0 && argv[0][0] == '-') {
70		if (strcmp(argv[0], "-a") != 0)
71			usage();
72		all++;
73		argc--, argv++;
74	}
75	do {
76		if (argc > 0) {
77			if (freopen(argv[0], "r", stdin) == NULL)
78				err(1, "%s", argv[0]);
79			argc--, argv++;
80		}
81		while (fgets(genbuf, BUFSIZ, stdin) != NULL) {
82			for (cp = linebuf; *cp; cp++)
83				continue;
84			if (cp > linebuf)
85				cp[-1] = 0;
86			tabify(all);
87			printf("%s", linebuf);
88		}
89	} while (argc > 0);
90	exit(0);
91}
92
93static void
94usage()
95{
96	fprintf(stderr, "usage: unexpand [-a] file ...\n");
97	exit(1);
98}
99
100void
101tabify(c)
102	char c;
103{
104	register char *cp, *dp;
105	register int dcol;
106	int ocol;
107
108	ocol = 0;
109	dcol = 0;
110	cp = genbuf, dp = linebuf;
111	for (;;) {
112		switch (*cp) {
113
114		case ' ':
115			dcol++;
116			break;
117
118		case '\t':
119			dcol += 8;
120			dcol &= ~07;
121			break;
122
123		default:
124			while (((ocol + 8) &~ 07) <= dcol) {
125				if (ocol + 1 == dcol)
126					break;
127				*dp++ = '\t';
128				ocol += 8;
129				ocol &= ~07;
130			}
131			while (ocol < dcol) {
132				*dp++ = ' ';
133				ocol++;
134			}
135			if (*cp == 0 || c == 0) {
136				strcpy(dp, cp);
137				return;
138			}
139			*dp++ = *cp;
140			ocol++, dcol++;
141		}
142		cp++;
143	}
144}
145