xref: /freebsd/usr.bin/unexpand/unexpand.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
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
35 static 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
42 static char sccsid[] = "@(#)unexpand.c	8.1 (Berkeley) 6/6/93";
43 #endif
44 static const char rcsid[] =
45   "$FreeBSD$";
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 #include <string.h>
54 
55 char	genbuf[BUFSIZ];
56 char	linebuf[BUFSIZ];
57 int	all;
58 
59 static void usage __P((void));
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 			usage();
73 		all++;
74 		argc--, argv++;
75 	}
76 	do {
77 		if (argc > 0) {
78 			if (freopen(argv[0], "r", stdin) == NULL)
79 				err(1, "%s", argv[0]);
80 			argc--, argv++;
81 		}
82 		while (fgets(genbuf, BUFSIZ, stdin) != NULL) {
83 			for (cp = linebuf; *cp; cp++)
84 				continue;
85 			if (cp > linebuf)
86 				cp[-1] = 0;
87 			tabify(all);
88 			printf("%s", linebuf);
89 		}
90 	} while (argc > 0);
91 	exit(0);
92 }
93 
94 static void
95 usage()
96 {
97 	fprintf(stderr, "usage: unexpand [-a] file ...\n");
98 	exit(1);
99 }
100 
101 void
102 tabify(c)
103 	char c;
104 {
105 	register char *cp, *dp;
106 	register int dcol;
107 	int ocol;
108 
109 	ocol = 0;
110 	dcol = 0;
111 	cp = genbuf, dp = linebuf;
112 	for (;;) {
113 		switch (*cp) {
114 
115 		case ' ':
116 			dcol++;
117 			break;
118 
119 		case '\t':
120 			dcol += 8;
121 			dcol &= ~07;
122 			break;
123 
124 		default:
125 			while (((ocol + 8) &~ 07) <= dcol) {
126 				if (ocol + 1 == dcol)
127 					break;
128 				*dp++ = '\t';
129 				ocol += 8;
130 				ocol &= ~07;
131 			}
132 			while (ocol < dcol) {
133 				*dp++ = ' ';
134 				ocol++;
135 			}
136 			if (*cp == 0 || c == 0) {
137 				strcpy(dp, cp);
138 				return;
139 			}
140 			*dp++ = *cp;
141 			ocol++, dcol++;
142 		}
143 		cp++;
144 	}
145 }
146