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
main(int argc,char * argv[])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
getstops(const char * spec)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
usage(void)177 usage(void)
178 {
179
180 (void)fprintf(stderr, "Usage: %s [-t tablist] [file ...]\n",
181 getprogname());
182 exit(EXIT_FAILURE);
183 }
184