1 /* $NetBSD: expand.c,v 1.14 2016/09/05 00:40:28 sevan 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 1.14 2016/09/05 00:40:28 sevan 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 static void usage(void) __dead;
59
60 int
main(int argc,char * argv[])61 main(int argc, char *argv[])
62 {
63 int c;
64 size_t n, column;
65
66 setprogname(argv[0]);
67
68 /* handle obsolete syntax */
69 while (argc > 1 &&
70 argv[1][0] == '-' && isdigit((unsigned char)argv[1][1])) {
71 getstops(&argv[1][1]);
72 argc--; argv++;
73 }
74
75 while ((c = getopt (argc, argv, "t:")) != -1) {
76 switch (c) {
77 case 't':
78 getstops(optarg);
79 break;
80 case '?':
81 default:
82 usage();
83 /* NOTREACHED */
84 }
85 }
86 argc -= optind;
87 argv += optind;
88
89 do {
90 if (argc > 0) {
91 if (freopen(argv[0], "r", stdin) == NULL)
92 err(EXIT_FAILURE, "Cannot open `%s'", argv[0]);
93 argc--, argv++;
94 }
95 column = 0;
96 while ((c = getchar()) != EOF) {
97 switch (c) {
98 case '\t':
99 if (nstops == 0) {
100 do {
101 putchar(' ');
102 column++;
103 } while (column & 07);
104 continue;
105 }
106 if (nstops == 1) {
107 do {
108 putchar(' ');
109 column++;
110 } while (((column - 1) % tabstops[0])
111 != (tabstops[0] - 1));
112 continue;
113 }
114 for (n = 0; n < nstops; n++)
115 if (tabstops[n] > column)
116 break;
117 if (n == nstops) {
118 putchar(' ');
119 column++;
120 continue;
121 }
122 while (column < tabstops[n]) {
123 putchar(' ');
124 column++;
125 }
126 continue;
127
128 case '\b':
129 if (column)
130 column--;
131 putchar('\b');
132 continue;
133
134 default:
135 putchar(c);
136 column++;
137 continue;
138
139 case '\n':
140 putchar(c);
141 column = 0;
142 continue;
143 }
144 }
145 } while (argc > 0);
146 return EXIT_SUCCESS;
147 }
148
149 static void
getstops(const char * spec)150 getstops(const char *spec)
151 {
152 int i;
153 const char *cp = spec;
154
155 nstops = 0;
156 for (;;) {
157 i = 0;
158 while (*cp >= '0' && *cp <= '9')
159 i = i * 10 + *cp++ - '0';
160 if (i <= 0 || i > 256)
161 errx(EXIT_FAILURE, "Too large tab stop spec `%d'", i);
162 if (nstops > 0 && (size_t)i <= tabstops[nstops-1])
163 errx(EXIT_FAILURE, "Out of order tabstop spec `%d'", i);
164 if (nstops == sizeof(tabstops) / sizeof(tabstops[0]) - 1)
165 errx(EXIT_FAILURE, "Too many tabstops");
166 tabstops[nstops++] = i;
167 if (*cp == '\0')
168 break;
169 if (*cp != ',' && *cp != ' ')
170 errx(EXIT_FAILURE, "Illegal tab stop spec `%s'", spec);
171 cp++;
172 }
173 }
174
175 static void
usage(void)176 usage(void)
177 {
178
179 (void)fprintf(stderr, "Usage: %s [-t tablist] [file ...]\n",
180 getprogname());
181 exit(EXIT_FAILURE);
182 }
183