xref: /freebsd/usr.bin/expand/expand.c (revision ef36b3f75658d201edb495068db5e1be49593de5)
1 /*
2  * Copyright (c) 1980, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef lint
31 static const char copyright[] =
32 "@(#) Copyright (c) 1980, 1993\n\
33 	The Regents of the University of California.  All rights reserved.\n";
34 #endif /* not lint */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)expand.c	8.1 (Berkeley) 6/9/93";
39 #endif
40 #endif /* not lint */
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <ctype.h>
45 #include <err.h>
46 #include <locale.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <unistd.h>
50 #include <wchar.h>
51 #include <wctype.h>
52 
53 /*
54  * expand - expand tabs to equivalent spaces
55  */
56 static int	nstops;
57 static int	tabstops[100];
58 
59 static void getstops(char *);
60 static void usage(void);
61 
62 int
63 main(int argc, char *argv[])
64 {
65 	const char *curfile;
66 	wint_t wc;
67 	int c, column;
68 	int n;
69 	int rval;
70 	int width;
71 
72 	setlocale(LC_CTYPE, "");
73 
74 	/* handle obsolete syntax */
75 	while (argc > 1 && argv[1][0] == '-' &&
76 	    isdigit((unsigned char)argv[1][1])) {
77 		getstops(&argv[1][1]);
78 		argc--; argv++;
79 	}
80 
81 	while ((c = getopt (argc, argv, "t:")) != -1) {
82 		switch (c) {
83 		case 't':
84 			getstops(optarg);
85 			break;
86 		case '?':
87 		default:
88 			usage();
89 			/* NOTREACHED */
90 		}
91 	}
92 	argc -= optind;
93 	argv += optind;
94 
95 	rval = 0;
96 	do {
97 		if (argc > 0) {
98 			if (freopen(argv[0], "r", stdin) == NULL) {
99 				warn("%s", argv[0]);
100 				rval = 1;
101 				argc--, argv++;
102 				continue;
103 			}
104 			curfile = argv[0];
105 			argc--, argv++;
106 		} else
107 			curfile = "stdin";
108 		column = 0;
109 		while ((wc = getwchar()) != WEOF) {
110 			switch (wc) {
111 			case '\t':
112 				if (nstops == 0) {
113 					do {
114 						putwchar(' ');
115 						column++;
116 					} while (column & 07);
117 					continue;
118 				}
119 				if (nstops == 1) {
120 					do {
121 						putwchar(' ');
122 						column++;
123 					} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
124 					continue;
125 				}
126 				for (n = 0; n < nstops; n++)
127 					if (tabstops[n] > column)
128 						break;
129 				if (n == nstops) {
130 					putwchar(' ');
131 					column++;
132 					continue;
133 				}
134 				while (column < tabstops[n]) {
135 					putwchar(' ');
136 					column++;
137 				}
138 				continue;
139 
140 			case '\b':
141 				if (column)
142 					column--;
143 				putwchar('\b');
144 				continue;
145 
146 			default:
147 				putwchar(wc);
148 				if ((width = wcwidth(wc)) > 0)
149 					column += width;
150 				continue;
151 
152 			case '\n':
153 				putwchar(wc);
154 				column = 0;
155 				continue;
156 			}
157 		}
158 		if (ferror(stdin)) {
159 			warn("%s", curfile);
160 			rval = 1;
161 		}
162 	} while (argc > 0);
163 	exit(rval);
164 }
165 
166 static void
167 getstops(char *cp)
168 {
169 	int i;
170 
171 	nstops = 0;
172 	for (;;) {
173 		i = 0;
174 		while (*cp >= '0' && *cp <= '9')
175 			i = i * 10 + *cp++ - '0';
176 		if (i <= 0)
177 			errx(1, "bad tab stop spec");
178 		if (nstops > 0 && i <= tabstops[nstops-1])
179 			errx(1, "bad tab stop spec");
180 		if (nstops == sizeof(tabstops) / sizeof(*tabstops))
181 			errx(1, "too many tab stops");
182 		tabstops[nstops++] = i;
183 		if (*cp == 0)
184 			break;
185 		if (*cp != ',' && !isblank((unsigned char)*cp))
186 			errx(1, "bad tab stop spec");
187 		cp++;
188 	}
189 }
190 
191 static void
192 usage(void)
193 {
194 	(void)fprintf (stderr, "usage: expand [-t tablist] [file ...]\n");
195 	exit(1);
196 }
197