xref: /openbsd-src/usr.bin/unexpand/unexpand.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: unexpand.c,v 1.3 1999/02/11 23:08:25 deraadt Exp $	*/
2 /*	$NetBSD: unexpand.c,v 1.5 1994/12/24 17:08:05 cgd Exp $	*/
3 
4 /*-
5  * Copyright (c) 1980, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 static char copyright[] =
39 "@(#) Copyright (c) 1980, 1993\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)unexpand.c	8.1 (Berkeley) 6/6/93";
46 #endif
47 static char rcsid[] = "$OpenBSD: unexpand.c,v 1.3 1999/02/11 23:08:25 deraadt Exp $";
48 #endif /* not lint */
49 
50 /*
51  * unexpand - put tabs into a file replacing blanks
52  */
53 #include <stdio.h>
54 #include <string.h>
55 
56 char	genbuf[BUFSIZ];
57 char	linebuf[BUFSIZ];
58 int	all;
59 
60 void tabify __P((char));
61 
62 int
63 main(argc, argv)
64 	int argc;
65 	char *argv[];
66 {
67 	register char *cp;
68 
69 	argc--, argv++;
70 	if (argc > 0 && argv[0][0] == '-') {
71 		if (strcmp(argv[0], "-a") != 0) {
72 			fprintf(stderr, "usage: unexpand [-a] [file ...]\n");
73 			exit(1);
74 		}
75 		all++;
76 		argc--, argv++;
77 	}
78 	do {
79 		if (argc > 0) {
80 			if (freopen(argv[0], "r", stdin) == NULL) {
81 				perror(argv[0]);
82 				exit(1);
83 			}
84 			argc--, argv++;
85 		}
86 		while (fgets(genbuf, BUFSIZ, stdin) != NULL) {
87 			for (cp = linebuf; *cp; cp++)
88 				continue;
89 			if (cp > linebuf)
90 				cp[-1] = 0;
91 			tabify(all);
92 			printf("%s", linebuf);
93 		}
94 	} while (argc > 0);
95 	exit(0);
96 }
97 
98 void
99 tabify(c)
100 	char c;
101 {
102 	register char *cp, *dp;
103 	register int dcol;
104 	int ocol;
105 
106 	ocol = 0;
107 	dcol = 0;
108 	cp = genbuf, dp = linebuf;
109 	for (;;) {
110 		switch (*cp) {
111 
112 		case ' ':
113 			dcol++;
114 			break;
115 
116 		case '\t':
117 			dcol += 8;
118 			dcol &= ~07;
119 			break;
120 
121 		default:
122 			while (((ocol + 8) &~ 07) <= dcol) {
123 				if (ocol + 1 == dcol)
124 					break;
125 				*dp++ = '\t';
126 				ocol += 8;
127 				ocol &= ~07;
128 			}
129 			while (ocol < dcol) {
130 				*dp++ = ' ';
131 				ocol++;
132 			}
133 			if (*cp == 0 || c == 0) {
134 				strcpy(dp, cp);
135 				return;
136 			}
137 			*dp++ = *cp;
138 			ocol++, dcol++;
139 		}
140 		cp++;
141 	}
142 }
143