xref: /netbsd-src/usr.bin/unexpand/unexpand.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: unexpand.c,v 1.12 2003/08/07 11:16:54 agc 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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1980, 1993\n\
35 	The Regents of the University of California.  All rights reserved.\n");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)unexpand.c	8.1 (Berkeley) 6/6/93";
41 #endif
42 __RCSID("$NetBSD: unexpand.c,v 1.12 2003/08/07 11:16:54 agc Exp $");
43 #endif /* not lint */
44 
45 /*
46  * unexpand - put tabs into a file replacing blanks
47  */
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <errno.h>
53 #include <err.h>
54 
55 char	genbuf[BUFSIZ];
56 char	linebuf[BUFSIZ];
57 
58 int	main(int, char **);
59 void	tabify(int, uint);
60 
61 int
62 main(int argc, char **argv)
63 {
64 	int all, c;
65 	uint tabsize;
66 	ulong l;
67 	char *ep;
68 
69 	setprogname(argv[0]);
70 
71 	all = 0;
72 	tabsize = 8;
73 	while ((c = getopt(argc, argv, "at:")) != -1) {
74 		switch (c) {
75 		case 'a':
76 			all++;
77 			break;
78 		case 't':
79 			errno = 0;
80 			l = strtoul(optarg, &ep, 0);
81 			/*
82 			 * If every input char is a tab, the line length
83 			 * must not exceed maxuint.
84 			 */
85 			tabsize = (int)l * BUFSIZ;
86 			tabsize /= BUFSIZ;
87 			if (*ep != 0 || errno != 0 || (ulong)tabsize != l)
88 				errx(EXIT_FAILURE, "Invalid tabstop \"%s\"",
89 				    optarg);
90 			break;
91 		case '?':
92 		default:
93 			fprintf(stderr, "usage: %s [-a] [-t tabstop] [file ...]\n",
94 				getprogname());
95 			exit(EXIT_FAILURE);
96 			/* NOTREACHED */
97 		}
98 	}
99 	argc -= optind;
100 	argv += optind;
101 
102 	do {
103 		if (argc > 0) {
104 			if (freopen(argv[0], "r", stdin) == NULL) {
105 				perror(argv[0]);
106 				exit(EXIT_FAILURE);
107 			}
108 			argc--, argv++;
109 		}
110 		while (fgets(genbuf, BUFSIZ, stdin) != NULL) {
111 			tabify(all, tabsize);
112 			printf("%s", linebuf);
113 		}
114 	} while (argc > 0);
115 	exit(EXIT_SUCCESS);
116 	/* NOTREACHED */
117 }
118 
119 void
120 tabify(int all, uint tabsize)
121 {
122 	char *cp, *dp;
123 	uint dcol;
124 	uint ocol;
125 	uint tcol;
126 
127 	ocol = 0;
128 	dcol = 0;
129 	cp = genbuf, dp = linebuf;
130 	for (;;) {
131 		switch (*cp) {
132 
133 		case ' ':
134 			dcol++;
135 			break;
136 
137 		case '\t':
138 			dcol = (dcol + tabsize) / tabsize * tabsize;
139 			break;
140 
141 		default:
142 			if (dcol > ocol + 1) {
143 				tcol = (ocol + tabsize) / tabsize * tabsize;
144 				while (tcol <= dcol) {
145 					*dp++ = '\t';
146 					ocol = tcol;
147 					tcol += tabsize;
148 				}
149 			}
150 			while (ocol < dcol) {
151 				*dp++ = ' ';
152 				ocol++;
153 			}
154 			if (*cp == 0 || all == 0) {
155 				strlcpy(dp, cp,
156 				    sizeof(linebuf) - (dp - linebuf));
157 				return;
158 			}
159 			*dp++ = *cp;
160 			dcol = ++ocol;
161 		}
162 		cp++;
163 	}
164 }
165