1 /* $OpenBSD: expand.c,v 1.15 2022/12/04 23:50:48 cheloha Exp $ */
2 /* $NetBSD: expand.c,v 1.5 1995/09/02 06:19:46 jtc Exp $ */
3
4 /*
5 * Copyright (c) 1980, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <ctype.h>
36 #include <unistd.h>
37 #include <err.h>
38
39 /*
40 * expand - expand tabs to equivalent spaces
41 */
42 int nstops;
43 int tabstops[100];
44
45 static void getstops(char *);
46 static void usage(void);
47
48 int
main(int argc,char * argv[])49 main(int argc, char *argv[])
50 {
51 int c, column;
52 int n;
53
54 if (pledge("stdio rpath", NULL) == -1)
55 err(1, "pledge");
56
57 /* handle obsolete syntax */
58 while (argc > 1 && argv[1][0] == '-' &&
59 isdigit((unsigned char)argv[1][1])) {
60 getstops(&argv[1][1]);
61 argc--; argv++;
62 }
63
64 while ((c = getopt (argc, argv, "t:")) != -1) {
65 switch (c) {
66 case 't':
67 getstops(optarg);
68 break;
69 default:
70 usage();
71 /* NOTREACHED */
72 }
73 }
74 argc -= optind;
75 argv += optind;
76
77 do {
78 if (argc > 0) {
79 if (freopen(argv[0], "r", stdin) == NULL)
80 err(1, "%s", argv[0]);
81 argc--, argv++;
82 }
83 column = 0;
84 while ((c = getchar()) != EOF) {
85 switch (c) {
86 case '\t':
87 if (nstops == 0) {
88 do {
89 putchar(' ');
90 column++;
91 } while (column & 07);
92 continue;
93 }
94 if (nstops == 1) {
95 do {
96 putchar(' ');
97 column++;
98 } while (((column - 1) %
99 tabstops[0]) != (tabstops[0] - 1));
100 continue;
101 }
102 for (n = 0; n < nstops; n++)
103 if (tabstops[n] > column)
104 break;
105 if (n == nstops) {
106 putchar(' ');
107 column++;
108 continue;
109 }
110 while (column < tabstops[n]) {
111 putchar(' ');
112 column++;
113 }
114 continue;
115
116 case '\b':
117 if (column)
118 column--;
119 putchar('\b');
120 continue;
121
122 default:
123 putchar(c);
124 column++;
125 continue;
126
127 case '\n':
128 putchar(c);
129 column = 0;
130 continue;
131 }
132 }
133 } while (argc > 0);
134 exit(0);
135 }
136
137 static void
getstops(char * cp)138 getstops(char *cp)
139 {
140 int i;
141
142 nstops = 0;
143 for (;;) {
144 i = 0;
145 while (*cp >= '0' && *cp <= '9')
146 i = i * 10 + *cp++ - '0';
147 if (i <= 0 || i > 256) {
148 bad:
149 errx(1, "Bad tab stop spec");
150 }
151 if (nstops > 0 && i <= tabstops[nstops-1])
152 goto bad;
153 if (nstops >= sizeof(tabstops) / sizeof(tabstops[0]))
154 errx(1, "Too many tab stops");
155 tabstops[nstops++] = i;
156 if (*cp == 0)
157 break;
158 if (*cp != ',' && *cp != ' ')
159 goto bad;
160 cp++;
161 }
162 }
163
164 static void
usage(void)165 usage(void)
166 {
167 extern char *__progname;
168 fprintf (stderr, "usage: %s [-t tablist] [file ...]\n", __progname);
169 exit(1);
170 }
171