xref: /freebsd/usr.bin/rev/rev.c (revision c11e094d96120a2e0e726ed9705ae0ec08db49b6)
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 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1987, 1992, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #if 0
41 #ifndef lint
42 static char sccsid[] = "@(#)rev.c	8.3 (Berkeley) 5/4/95";
43 #endif /* not lint */
44 #endif
45 
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 #include <sys/types.h>
50 
51 #include <err.h>
52 #include <errno.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57 
58 void usage(void);
59 
60 int
61 main(argc, argv)
62 	int argc;
63 	char *argv[];
64 {
65 	const char *filename, *p, *t;
66 	FILE *fp;
67 	size_t len;
68 	int ch, rval;
69 
70 	while ((ch = getopt(argc, argv, "")) != -1)
71 		switch(ch) {
72 		case '?':
73 		default:
74 			usage();
75 		}
76 
77 	argc -= optind;
78 	argv += optind;
79 
80 	fp = stdin;
81 	filename = "stdin";
82 	rval = 0;
83 	do {
84 		if (*argv) {
85 			if ((fp = fopen(*argv, "r")) == NULL) {
86 				warn("%s", *argv);
87 				rval = 1;
88 				++argv;
89 				continue;
90 			}
91 			filename = *argv++;
92 		}
93 		while ((p = fgetln(fp, &len)) != NULL) {
94 			if (p[len - 1] == '\n')
95 				--len;
96 			t = p + len - 1;
97 			for (t = p + len - 1; t >= p; --t)
98 				putchar(*t);
99 			putchar('\n');
100 		}
101 		if (ferror(fp)) {
102 			warn("%s", filename);
103 			rval = 1;
104 		}
105 		(void)fclose(fp);
106 	} while(*argv);
107 	exit(rval);
108 }
109 
110 void
111 usage()
112 {
113 	(void)fprintf(stderr, "usage: rev [file ...]\n");
114 	exit(1);
115 }
116