xref: /dflybsd-src/usr.bin/rev/rev.c (revision 1de703daf67320d643c7695d9bf7ec54c33d5512)
1 /*-
2  * Copyright (c) 1987, 1992, 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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#) Copyright (c) 1987, 1992, 1993 The Regents of the University of California.  All rights reserved.
34  * @(#)rev.c	8.3 (Berkeley) 5/4/95
35  */
36 
37 #include <sys/types.h>
38 
39 #include <err.h>
40 #include <errno.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 void usage __P((void));
47 
48 int
49 main(argc, argv)
50 	int argc;
51 	char *argv[];
52 {
53 	register char *filename, *p, *t;
54 	FILE *fp;
55 	size_t len;
56 	int ch, rval;
57 
58 	while ((ch = getopt(argc, argv, "")) != -1)
59 		switch(ch) {
60 		case '?':
61 		default:
62 			usage();
63 		}
64 
65 	argc -= optind;
66 	argv += optind;
67 
68 	fp = stdin;
69 	filename = "stdin";
70 	rval = 0;
71 	do {
72 		if (*argv) {
73 			if ((fp = fopen(*argv, "r")) == NULL) {
74 				warn("%s", *argv);
75 				rval = 1;
76 				++argv;
77 				continue;
78 			}
79 			filename = *argv++;
80 		}
81 		while ((p = fgetln(fp, &len)) != NULL) {
82 			if (p[len - 1] == '\n')
83 				--len;
84 			t = p + len - 1;
85 			for (t = p + len - 1; t >= p; --t)
86 				putchar(*t);
87 			putchar('\n');
88 		}
89 		if (ferror(fp)) {
90 			warn("%s", filename);
91 			rval = 1;
92 		}
93 		(void)fclose(fp);
94 	} while(*argv);
95 	exit(rval);
96 }
97 
98 void
99 usage()
100 {
101 	(void)fprintf(stderr, "usage: rev [file ...]\n");
102 	exit(1);
103 }
104