xref: /freebsd/usr.bin/expand/expand.c (revision 5b31cc94b10d4bb7109c6b27940a0fc76a44a331)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 #ifndef lint
33 static const char copyright[] =
34 "@(#) 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 #endif /* not lint */
40 #include <sys/cdefs.h>
41 #include <ctype.h>
42 #include <err.h>
43 #include <locale.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <unistd.h>
47 #include <wchar.h>
48 #include <wctype.h>
49 
50 /*
51  * expand - expand tabs to equivalent spaces
52  */
53 static int	nstops;
54 static int	tabstops[100];
55 
56 static void getstops(char *);
57 static void usage(void) __dead2;
58 
59 int
60 main(int argc, char *argv[])
61 {
62 	const char *curfile;
63 	wint_t wc;
64 	int c, column;
65 	int n;
66 	int rval;
67 	int width;
68 
69 	setlocale(LC_CTYPE, "");
70 
71 	/* handle obsolete syntax */
72 	while (argc > 1 && argv[1][0] == '-' &&
73 	    isdigit((unsigned char)argv[1][1])) {
74 		getstops(&argv[1][1]);
75 		argc--; argv++;
76 	}
77 
78 	while ((c = getopt (argc, argv, "t:")) != -1) {
79 		switch (c) {
80 		case 't':
81 			getstops(optarg);
82 			break;
83 		case '?':
84 		default:
85 			usage();
86 			/* NOTREACHED */
87 		}
88 	}
89 	argc -= optind;
90 	argv += optind;
91 
92 	rval = 0;
93 	do {
94 		if (argc > 0) {
95 			if (freopen(argv[0], "r", stdin) == NULL) {
96 				warn("%s", argv[0]);
97 				rval = 1;
98 				argc--, argv++;
99 				continue;
100 			}
101 			curfile = argv[0];
102 			argc--, argv++;
103 		} else
104 			curfile = "stdin";
105 		column = 0;
106 		while ((wc = getwchar()) != WEOF) {
107 			switch (wc) {
108 			case '\t':
109 				if (nstops == 0) {
110 					do {
111 						putwchar(' ');
112 						column++;
113 					} while (column & 07);
114 					continue;
115 				}
116 				if (nstops == 1) {
117 					do {
118 						putwchar(' ');
119 						column++;
120 					} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
121 					continue;
122 				}
123 				for (n = 0; n < nstops; n++)
124 					if (tabstops[n] > column)
125 						break;
126 				if (n == nstops) {
127 					putwchar(' ');
128 					column++;
129 					continue;
130 				}
131 				while (column < tabstops[n]) {
132 					putwchar(' ');
133 					column++;
134 				}
135 				continue;
136 
137 			case '\b':
138 				if (column)
139 					column--;
140 				putwchar('\b');
141 				continue;
142 
143 			default:
144 				putwchar(wc);
145 				if ((width = wcwidth(wc)) > 0)
146 					column += width;
147 				continue;
148 
149 			case '\n':
150 				putwchar(wc);
151 				column = 0;
152 				continue;
153 			}
154 		}
155 		if (ferror(stdin)) {
156 			warn("%s", curfile);
157 			rval = 1;
158 		}
159 	} while (argc > 0);
160 	exit(rval);
161 }
162 
163 static void
164 getstops(char *cp)
165 {
166 	int i;
167 
168 	nstops = 0;
169 	for (;;) {
170 		i = 0;
171 		while (*cp >= '0' && *cp <= '9')
172 			i = i * 10 + *cp++ - '0';
173 		if (i <= 0)
174 			errx(1, "bad tab stop spec");
175 		if (nstops > 0 && i <= tabstops[nstops-1])
176 			errx(1, "bad tab stop spec");
177 		if (nstops == sizeof(tabstops) / sizeof(*tabstops))
178 			errx(1, "too many tab stops");
179 		tabstops[nstops++] = i;
180 		if (*cp == 0)
181 			break;
182 		if (*cp != ',' && !isblank((unsigned char)*cp))
183 			errx(1, "bad tab stop spec");
184 		cp++;
185 	}
186 }
187 
188 static void
189 usage(void)
190 {
191 	(void)fprintf (stderr, "usage: expand [-t tablist] [file ...]\n");
192 	exit(1);
193 }
194