xref: /freebsd/usr.bin/rev/rev.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
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 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1987, 1992, 1993\n\
35 	The Regents of the University of California.  All rights reserved.\n";
36 #endif /* not lint */
37 
38 #if 0
39 #ifndef lint
40 static char sccsid[] = "@(#)rev.c	8.3 (Berkeley) 5/4/95";
41 #endif /* not lint */
42 #endif
43 
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include <sys/types.h>
48 
49 #include <err.h>
50 #include <errno.h>
51 #include <locale.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 #include <wchar.h>
57 
58 static void usage(void) __dead2;
59 
60 int
61 main(int argc, char *argv[])
62 {
63 	const char *filename;
64 	wchar_t *p, *t;
65 	FILE *fp;
66 	size_t len;
67 	int ch, rval;
68 
69 	setlocale(LC_ALL, "");
70 
71 	while ((ch = getopt(argc, argv, "")) != -1)
72 		switch(ch) {
73 		case '?':
74 		default:
75 			usage();
76 		}
77 
78 	argc -= optind;
79 	argv += optind;
80 
81 	fp = stdin;
82 	filename = "stdin";
83 	rval = 0;
84 	do {
85 		if (*argv) {
86 			if ((fp = fopen(*argv, "r")) == NULL) {
87 				warn("%s", *argv);
88 				rval = 1;
89 				++argv;
90 				continue;
91 			}
92 			filename = *argv++;
93 		}
94 		while ((p = fgetwln(fp, &len)) != NULL) {
95 			if (p[len - 1] == '\n')
96 				--len;
97 			for (t = p + len - 1; t >= p; --t)
98 				putwchar(*t);
99 			putwchar('\n');
100 		}
101 		if (ferror(fp)) {
102 			warn("%s", filename);
103 			clearerr(fp);
104 			rval = 1;
105 		}
106 		(void)fclose(fp);
107 	} while(*argv);
108 	exit(rval);
109 }
110 
111 void
112 usage(void)
113 {
114 	(void)fprintf(stderr, "usage: rev [file ...]\n");
115 	exit(1);
116 }
117