xref: /freebsd/usr.bin/expand/expand.c (revision a0409676120c1e558d0ade943019934e0f15118d)
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 #if 0
40 static char sccsid[] = "@(#)expand.c	8.1 (Berkeley) 6/9/93";
41 #endif
42 #endif /* not lint */
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
45 
46 #include <ctype.h>
47 #include <err.h>
48 #include <locale.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <unistd.h>
52 #include <wchar.h>
53 #include <wctype.h>
54 
55 /*
56  * expand - expand tabs to equivalent spaces
57  */
58 static int	nstops;
59 static int	tabstops[100];
60 
61 static void getstops(char *);
62 static void usage(void) __dead2;
63 
64 int
65 main(int argc, char *argv[])
66 {
67 	const char *curfile;
68 	wint_t wc;
69 	int c, column;
70 	int n;
71 	int rval;
72 	int width;
73 
74 	setlocale(LC_CTYPE, "");
75 
76 	/* handle obsolete syntax */
77 	while (argc > 1 && argv[1][0] == '-' &&
78 	    isdigit((unsigned char)argv[1][1])) {
79 		getstops(&argv[1][1]);
80 		argc--; argv++;
81 	}
82 
83 	while ((c = getopt (argc, argv, "t:")) != -1) {
84 		switch (c) {
85 		case 't':
86 			getstops(optarg);
87 			break;
88 		case '?':
89 		default:
90 			usage();
91 			/* NOTREACHED */
92 		}
93 	}
94 	argc -= optind;
95 	argv += optind;
96 
97 	rval = 0;
98 	do {
99 		if (argc > 0) {
100 			if (freopen(argv[0], "r", stdin) == NULL) {
101 				warn("%s", argv[0]);
102 				rval = 1;
103 				argc--, argv++;
104 				continue;
105 			}
106 			curfile = argv[0];
107 			argc--, argv++;
108 		} else
109 			curfile = "stdin";
110 		column = 0;
111 		while ((wc = getwchar()) != WEOF) {
112 			switch (wc) {
113 			case '\t':
114 				if (nstops == 0) {
115 					do {
116 						putwchar(' ');
117 						column++;
118 					} while (column & 07);
119 					continue;
120 				}
121 				if (nstops == 1) {
122 					do {
123 						putwchar(' ');
124 						column++;
125 					} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
126 					continue;
127 				}
128 				for (n = 0; n < nstops; n++)
129 					if (tabstops[n] > column)
130 						break;
131 				if (n == nstops) {
132 					putwchar(' ');
133 					column++;
134 					continue;
135 				}
136 				while (column < tabstops[n]) {
137 					putwchar(' ');
138 					column++;
139 				}
140 				continue;
141 
142 			case '\b':
143 				if (column)
144 					column--;
145 				putwchar('\b');
146 				continue;
147 
148 			default:
149 				putwchar(wc);
150 				if ((width = wcwidth(wc)) > 0)
151 					column += width;
152 				continue;
153 
154 			case '\n':
155 				putwchar(wc);
156 				column = 0;
157 				continue;
158 			}
159 		}
160 		if (ferror(stdin)) {
161 			warn("%s", curfile);
162 			rval = 1;
163 		}
164 	} while (argc > 0);
165 	exit(rval);
166 }
167 
168 static void
169 getstops(char *cp)
170 {
171 	int i;
172 
173 	nstops = 0;
174 	for (;;) {
175 		i = 0;
176 		while (*cp >= '0' && *cp <= '9')
177 			i = i * 10 + *cp++ - '0';
178 		if (i <= 0)
179 			errx(1, "bad tab stop spec");
180 		if (nstops > 0 && i <= tabstops[nstops-1])
181 			errx(1, "bad tab stop spec");
182 		if (nstops == sizeof(tabstops) / sizeof(*tabstops))
183 			errx(1, "too many tab stops");
184 		tabstops[nstops++] = i;
185 		if (*cp == 0)
186 			break;
187 		if (*cp != ',' && !isblank((unsigned char)*cp))
188 			errx(1, "bad tab stop spec");
189 		cp++;
190 	}
191 }
192 
193 static void
194 usage(void)
195 {
196 	(void)fprintf (stderr, "usage: expand [-t tablist] [file ...]\n");
197 	exit(1);
198 }
199