xref: /netbsd-src/usr.bin/unexpand/unexpand.c (revision 5f7096188587a2c7c95fa3c69b78e1ec9c7923d0)
1 /*-
2  * Copyright (c) 1980 The Regents of the University of California.
3  * 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
35 char copyright[] =
36 "@(#) Copyright (c) 1980 The Regents of the University of California.\n\
37  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 /*static char sccsid[] = "from: @(#)unexpand.c	5.3 (Berkeley) 4/18/91";*/
42 static char rcsid[] = "$Id: unexpand.c,v 1.2 1993/08/01 18:04:04 mycroft Exp $";
43 #endif /* not lint */
44 
45 /*
46  * unexpand - put tabs into a file replacing blanks
47  */
48 #include <stdio.h>
49 
50 char	genbuf[BUFSIZ];
51 char	linebuf[BUFSIZ];
52 int	all;
53 
54 main(argc, argv)
55 	int argc;
56 	char *argv[];
57 {
58 	register char *cp;
59 
60 	argc--, argv++;
61 	if (argc > 0 && argv[0][0] == '-') {
62 		if (strcmp(argv[0], "-a") != 0) {
63 			fprintf(stderr, "usage: unexpand [ -a ] file ...\n");
64 			exit(1);
65 		}
66 		all++;
67 		argc--, argv++;
68 	}
69 	do {
70 		if (argc > 0) {
71 			if (freopen(argv[0], "r", stdin) == NULL) {
72 				perror(argv[0]);
73 				exit(1);
74 			}
75 			argc--, argv++;
76 		}
77 		while (fgets(genbuf, BUFSIZ, stdin) != NULL) {
78 			for (cp = linebuf; *cp; cp++)
79 				continue;
80 			if (cp > linebuf)
81 				cp[-1] = 0;
82 			tabify(all);
83 			printf("%s", linebuf);
84 		}
85 	} while (argc > 0);
86 	exit(0);
87 }
88 
89 tabify(c)
90 	char c;
91 {
92 	register char *cp, *dp;
93 	register int dcol;
94 	int ocol;
95 
96 	ocol = 0;
97 	dcol = 0;
98 	cp = genbuf, dp = linebuf;
99 	for (;;) {
100 		switch (*cp) {
101 
102 		case ' ':
103 			dcol++;
104 			break;
105 
106 		case '\t':
107 			dcol += 8;
108 			dcol &= ~07;
109 			break;
110 
111 		default:
112 			while (((ocol + 8) &~ 07) <= dcol) {
113 				if (ocol + 1 == dcol)
114 					break;
115 				*dp++ = '\t';
116 				ocol += 8;
117 				ocol &= ~07;
118 			}
119 			while (ocol < dcol) {
120 				*dp++ = ' ';
121 				ocol++;
122 			}
123 			if (*cp == 0 || c == 0) {
124 				strcpy(dp, cp);
125 				return;
126 			}
127 			*dp++ = *cp;
128 			ocol++, dcol++;
129 		}
130 		cp++;
131 	}
132 }
133