xref: /freebsd/usr.bin/rev/rev.c (revision f5463265955b829775bbb32e1fd0bc11dafc36ce)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1987, 1992, 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/types.h>
33 
34 #include <err.h>
35 #include <errno.h>
36 #include <locale.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <unistd.h>
41 #include <wchar.h>
42 
43 static void usage(void) __dead2;
44 
45 int
46 main(int argc, char *argv[])
47 {
48 	const char *filename;
49 	wchar_t *p, *t;
50 	FILE *fp;
51 	size_t len;
52 	int ch, rval;
53 
54 	setlocale(LC_ALL, "");
55 
56 	while ((ch = getopt(argc, argv, "")) != -1)
57 		switch(ch) {
58 		case '?':
59 		default:
60 			usage();
61 		}
62 
63 	argc -= optind;
64 	argv += optind;
65 
66 	fp = stdin;
67 	filename = "stdin";
68 	rval = 0;
69 	do {
70 		if (*argv) {
71 			if ((fp = fopen(*argv, "r")) == NULL) {
72 				warn("%s", *argv);
73 				rval = 1;
74 				++argv;
75 				continue;
76 			}
77 			filename = *argv++;
78 		}
79 		while ((p = fgetwln(fp, &len)) != NULL) {
80 			if (p[len - 1] == '\n')
81 				--len;
82 			for (t = p + len - 1; t >= p; --t)
83 				putwchar(*t);
84 			putwchar('\n');
85 		}
86 		if (ferror(fp)) {
87 			warn("%s", filename);
88 			clearerr(fp);
89 			rval = 1;
90 		}
91 		(void)fclose(fp);
92 	} while(*argv);
93 	exit(rval);
94 }
95 
96 void
97 usage(void)
98 {
99 	(void)fprintf(stderr, "usage: rev [file ...]\n");
100 	exit(1);
101 }
102