xref: /freebsd/usr.bin/unexpand/unexpand.c (revision afe61c15161c324a7af299a9b8457aba5afc92db)
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 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 static char sccsid[] = "@(#)unexpand.c	8.1 (Berkeley) 6/6/93";
42 #endif /* not lint */
43 
44 /*
45  * unexpand - put tabs into a file replacing blanks
46  */
47 #include <stdio.h>
48 
49 char	genbuf[BUFSIZ];
50 char	linebuf[BUFSIZ];
51 int	all;
52 
53 main(argc, argv)
54 	int argc;
55 	char *argv[];
56 {
57 	register char *cp;
58 
59 	argc--, argv++;
60 	if (argc > 0 && argv[0][0] == '-') {
61 		if (strcmp(argv[0], "-a") != 0) {
62 			fprintf(stderr, "usage: unexpand [ -a ] file ...\n");
63 			exit(1);
64 		}
65 		all++;
66 		argc--, argv++;
67 	}
68 	do {
69 		if (argc > 0) {
70 			if (freopen(argv[0], "r", stdin) == NULL) {
71 				perror(argv[0]);
72 				exit(1);
73 			}
74 			argc--, argv++;
75 		}
76 		while (fgets(genbuf, BUFSIZ, stdin) != NULL) {
77 			for (cp = linebuf; *cp; cp++)
78 				continue;
79 			if (cp > linebuf)
80 				cp[-1] = 0;
81 			tabify(all);
82 			printf("%s", linebuf);
83 		}
84 	} while (argc > 0);
85 	exit(0);
86 }
87 
88 tabify(c)
89 	char c;
90 {
91 	register char *cp, *dp;
92 	register int dcol;
93 	int ocol;
94 
95 	ocol = 0;
96 	dcol = 0;
97 	cp = genbuf, dp = linebuf;
98 	for (;;) {
99 		switch (*cp) {
100 
101 		case ' ':
102 			dcol++;
103 			break;
104 
105 		case '\t':
106 			dcol += 8;
107 			dcol &= ~07;
108 			break;
109 
110 		default:
111 			while (((ocol + 8) &~ 07) <= dcol) {
112 				if (ocol + 1 == dcol)
113 					break;
114 				*dp++ = '\t';
115 				ocol += 8;
116 				ocol &= ~07;
117 			}
118 			while (ocol < dcol) {
119 				*dp++ = ' ';
120 				ocol++;
121 			}
122 			if (*cp == 0 || c == 0) {
123 				strcpy(dp, cp);
124 				return;
125 			}
126 			*dp++ = *cp;
127 			ocol++, dcol++;
128 		}
129 		cp++;
130 	}
131 }
132