xref: /minix/usr.bin/expand/expand.c (revision ebfedea0)
1 /*	$NetBSD: expand.c,v 1.13 2009/04/12 02:51:36 lukem 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\
35  The Regents of the University of California.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)expand.c	8.1 (Berkeley) 6/9/93";
41 #endif
42 __RCSID("$NetBSD: expand.c,v 1.13 2009/04/12 02:51:36 lukem Exp $");
43 #endif /* not lint */
44 
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <ctype.h>
48 #include <unistd.h>
49 #include <err.h>
50 
51 /*
52  * expand - expand tabs to equivalent spaces
53  */
54 size_t	nstops;
55 size_t	tabstops[100];
56 
57 static	void	getstops(const char *);
58 	int	main(int, char **);
59 static	void	usage(void) __dead;
60 
61 int
62 main(int argc, char *argv[])
63 {
64 	int c;
65 	size_t n, column;
66 
67 	setprogname(argv[0]);
68 
69 	/* handle obsolete syntax */
70 	while (argc > 1 &&
71 	    argv[1][0] == '-' && isdigit((unsigned char)argv[1][1])) {
72 		getstops(&argv[1][1]);
73 		argc--; argv++;
74 	}
75 
76 	while ((c = getopt (argc, argv, "t:")) != -1) {
77 		switch (c) {
78 		case 't':
79 			getstops(optarg);
80 			break;
81 		case '?':
82 		default:
83 			usage();
84 			/* NOTREACHED */
85 		}
86 	}
87 	argc -= optind;
88 	argv += optind;
89 
90 	do {
91 		if (argc > 0) {
92 			if (freopen(argv[0], "r", stdin) == NULL)
93 				err(EXIT_FAILURE, "Cannot open `%s'", argv[0]);
94 			argc--, argv++;
95 		}
96 		column = 0;
97 		while ((c = getchar()) != EOF) {
98 			switch (c) {
99 			case '\t':
100 				if (nstops == 0) {
101 					do {
102 						putchar(' ');
103 						column++;
104 					} while (column & 07);
105 					continue;
106 				}
107 				if (nstops == 1) {
108 					do {
109 						putchar(' ');
110 						column++;
111 					} while (((column - 1) % tabstops[0])
112 					    != (tabstops[0] - 1));
113 					continue;
114 				}
115 				for (n = 0; n < nstops; n++)
116 					if (tabstops[n] > column)
117 						break;
118 				if (n == nstops) {
119 					putchar(' ');
120 					column++;
121 					continue;
122 				}
123 				while (column < tabstops[n]) {
124 					putchar(' ');
125 					column++;
126 				}
127 				continue;
128 
129 			case '\b':
130 				if (column)
131 					column--;
132 				putchar('\b');
133 				continue;
134 
135 			default:
136 				putchar(c);
137 				column++;
138 				continue;
139 
140 			case '\n':
141 				putchar(c);
142 				column = 0;
143 				continue;
144 			}
145 		}
146 	} while (argc > 0);
147 	return EXIT_SUCCESS;
148 }
149 
150 static void
151 getstops(const char *spec)
152 {
153 	int i;
154 	const char *cp = spec;
155 
156 	nstops = 0;
157 	for (;;) {
158 		i = 0;
159 		while (*cp >= '0' && *cp <= '9')
160 			i = i * 10 + *cp++ - '0';
161 		if (i <= 0 || i > 256)
162 			errx(EXIT_FAILURE, "Too large tab stop spec `%d'", i);
163 		if (nstops > 0 && (size_t)i <= tabstops[nstops-1])
164 			errx(EXIT_FAILURE, "Out of order tabstop spec `%d'", i);
165 		if (nstops == sizeof(tabstops) / sizeof(tabstops[0]) - 1)
166 			errx(EXIT_FAILURE, "Too many tabstops");
167 		tabstops[nstops++] = i;
168 		if (*cp == '\0')
169 			break;
170 		if (*cp != ',' && *cp != ' ')
171 			errx(EXIT_FAILURE, "Illegal tab stop spec `%s'", spec);
172 		cp++;
173 	}
174 }
175 
176 static void
177 usage(void)
178 {
179 
180 	(void)fprintf(stderr, "Usage: %s [-t tablist] [file ...]\n",
181 	    getprogname());
182 	exit(EXIT_FAILURE);
183 }
184