xref: /netbsd-src/usr.bin/rev/rev.c (revision d877c4c3c02304002c0642d7f34a58d07138d6a9)
1 /*	$NetBSD: rev.c,v 1.9 2009/04/13 04:36:34 lukem Exp $	*/
2 
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/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1987, 1992, 1993\
35  The Regents of the University of California.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)rev.c	8.3 (Berkeley) 5/4/95";
41 #else
42 __RCSID("$NetBSD: rev.c,v 1.9 2009/04/13 04:36:34 lukem Exp $");
43 #endif
44 #endif /* not lint */
45 
46 #include <sys/types.h>
47 
48 #include <err.h>
49 #include <errno.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 
55 int	main __P((int, char **));
56 void	usage __P((void));
57 
58 int
59 main(argc, argv)
60 	int argc;
61 	char *argv[];
62 {
63 	const char *filename;
64 	char *p, *t;
65 	FILE *fp;
66 	size_t len;
67 	int ch, rval;
68 
69 	while ((ch = getopt(argc, argv, "")) != -1)
70 		switch(ch) {
71 		case '?':
72 		default:
73 			usage();
74 		}
75 
76 	argc -= optind;
77 	argv += optind;
78 
79 	fp = stdin;
80 	filename = "stdin";
81 	rval = 0;
82 	do {
83 		if (*argv) {
84 			if ((fp = fopen(*argv, "r")) == NULL) {
85 				warn("%s", *argv);
86 				rval = 1;
87 				++argv;
88 				continue;
89 			}
90 			filename = *argv++;
91 		}
92 		while ((p = fgetln(fp, &len)) != NULL) {
93 			if (p[len - 1] == '\n')
94 				--len;
95 			t = p + len - 1;
96 			for (t = p + len - 1; t >= p; --t)
97 				putchar(*t);
98 			putchar('\n');
99 		}
100 		if (ferror(fp)) {
101 			warn("%s", filename);
102 			rval = 1;
103 		}
104 		(void)fclose(fp);
105 	} while(*argv);
106 	exit(rval);
107 }
108 
109 void
110 usage()
111 {
112 	(void)fprintf(stderr, "usage: rev [file ...]\n");
113 	exit(1);
114 }
115