xref: /openbsd-src/usr.bin/rev/rev.c (revision 800a8ade7bb9667398282c53d4bb5e8ac8ee11be)
1 /*	$OpenBSD: rev.c,v 1.12 2015/10/09 01:37:08 deraadt Exp $	*/
2 /*	$NetBSD: rev.c,v 1.5 1995/09/28 08:49:40 tls Exp $	*/
3 
4 /*-
5  * Copyright (c) 1987, 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/types.h>
34 
35 #include <err.h>
36 #include <errno.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <unistd.h>
41 
42 void usage(void);
43 
44 int
45 main(int argc, char *argv[])
46 {
47 	char *filename, *p, *t;
48 	FILE *fp;
49 	size_t len;
50 	int ch, rval;
51 
52 	if (pledge("stdio rpath", NULL) == -1)
53 		err(1, "pledge");
54 
55 	while ((ch = getopt(argc, argv, "")) != -1)
56 		switch(ch) {
57 		case '?':
58 		default:
59 			usage();
60 		}
61 
62 	argc -= optind;
63 	argv += optind;
64 
65 	fp = stdin;
66 	filename = "stdin";
67 	rval = 0;
68 	do {
69 		if (*argv) {
70 			if ((fp = fopen(*argv, "r")) == NULL) {
71 				warn("%s", *argv);
72 				rval = 1;
73 				++argv;
74 				continue;
75 			}
76 			filename = *argv++;
77 		}
78 		while ((p = fgetln(fp, &len)) != NULL) {
79 			if (p[len - 1] == '\n')
80 				--len;
81 			for (t = p + len - 1; t >= p; --t)
82 				putchar(*t);
83 			putchar('\n');
84 		}
85 		if (ferror(fp)) {
86 			warn("%s", filename);
87 			rval = 1;
88 		}
89 		(void)fclose(fp);
90 	} while(*argv);
91 	exit(rval);
92 }
93 
94 void
95 usage(void)
96 {
97 	extern char *__progname;
98 
99 	(void)fprintf(stderr, "usage: %s [file ...]\n", __progname);
100 	exit(1);
101 }
102