xref: /netbsd-src/usr.bin/unexpand/unexpand.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*	$NetBSD: unexpand.c,v 1.10 2003/04/08 10:47:03 dsl Exp $	*/
2 
3 /*-
4  * Copyright (c) 1980, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1980, 1993\n\
39 	The Regents of the University of California.  All rights reserved.\n");
40 #endif /* not lint */
41 
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)unexpand.c	8.1 (Berkeley) 6/6/93";
45 #endif
46 __RCSID("$NetBSD: unexpand.c,v 1.10 2003/04/08 10:47:03 dsl Exp $");
47 #endif /* not lint */
48 
49 /*
50  * unexpand - put tabs into a file replacing blanks
51  */
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 #include <errno.h>
57 #include <err.h>
58 
59 char	genbuf[BUFSIZ];
60 char	linebuf[BUFSIZ];
61 
62 int	main(int, char **);
63 void	tabify(int, uint);
64 
65 int
66 main(int argc, char **argv)
67 {
68 	int all, c;
69 	uint tabsize;
70 	ulong l;
71 	char *ep;
72 
73 	setprogname(argv[0]);
74 
75 	all = 0;
76 	tabsize = 8;
77 	while ((c = getopt(argc, argv, "at:")) != -1) {
78 		switch (c) {
79 		case 'a':
80 			all++;
81 			break;
82 		case 't':
83 			errno = 0;
84 			l = strtoul(optarg, &ep, 0);
85 			/*
86 			 * If every input char is a tab, the line length
87 			 * must not exceed maxuint.
88 			 */
89 			tabsize = (int)l * BUFSIZ;
90 			tabsize /= BUFSIZ;
91 			if (*ep != 0 || errno != 0 || (ulong)tabsize != l)
92 				errx(EXIT_FAILURE, "Invalid tabstop \"%s\"",
93 				    optarg);
94 			break;
95 		case '?':
96 		default:
97 			fprintf(stderr, "usage: %s [-a] [-t tabstop] [file ...]\n",
98 				getprogname());
99 			exit(EXIT_FAILURE);
100 			/* NOTREACHED */
101 		}
102 	}
103 	argc -= optind;
104 	argv += optind;
105 
106 	do {
107 		if (argc > 0) {
108 			if (freopen(argv[0], "r", stdin) == NULL) {
109 				perror(argv[0]);
110 				exit(EXIT_FAILURE);
111 			}
112 			argc--, argv++;
113 		}
114 		while (fgets(genbuf, BUFSIZ, stdin) != NULL) {
115 			tabify(all, tabsize);
116 			printf("%s", linebuf);
117 		}
118 	} while (argc > 0);
119 	exit(EXIT_SUCCESS);
120 	/* NOTREACHED */
121 }
122 
123 void
124 tabify(int all, uint tabsize)
125 {
126 	char *cp, *dp;
127 	uint dcol;
128 	uint ocol;
129 	uint tcol;
130 
131 	ocol = 0;
132 	dcol = 0;
133 	cp = genbuf, dp = linebuf;
134 	for (;;) {
135 		switch (*cp) {
136 
137 		case ' ':
138 			dcol++;
139 			break;
140 
141 		case '\t':
142 			dcol = (dcol + tabsize) / tabsize * tabsize;
143 			break;
144 
145 		default:
146 			if (dcol > ocol + 1) {
147 				tcol = (ocol + tabsize) / tabsize * tabsize;
148 				while (tcol <= dcol) {
149 					*dp++ = '\t';
150 					ocol = tcol;
151 					tcol += tabsize;
152 				}
153 			}
154 			while (ocol < dcol) {
155 				*dp++ = ' ';
156 				ocol++;
157 			}
158 			if (*cp == 0 || all == 0) {
159 				strcpy(dp, cp);
160 				return;
161 			}
162 			*dp++ = *cp;
163 			dcol = ++ocol;
164 		}
165 		cp++;
166 	}
167 }
168