xref: /netbsd-src/usr.bin/rev/rev.c (revision cda4f8f6ee55684e8d311b86c99ea59191e6b74f)
1 /*-
2  * Copyright (c) 1987, 1992 The Regents of the University of California.
3  * 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 char copyright[] =
36 "@(#) Copyright (c) 1987, 1992 The Regents of the University of California.\n\
37  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 static char sccsid[] = "@(#)rev.c	5.2 (Berkeley) 3/21/92";
42 #endif /* not lint */
43 
44 #include <sys/types.h>
45 #include <errno.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 
50 void usage __P((void));
51 void warn __P((const char *, ...));
52 
53 int
54 main(argc, argv)
55 	int argc;
56 	char *argv[];
57 {
58 	register char *filename, *p, *t;
59 	FILE *fp;
60 	size_t len;
61 	int ch, rval;
62 
63 	while ((ch = getopt(argc, argv, "")) != EOF)
64 		switch(ch) {
65 		case '?':
66 		default:
67 			usage();
68 		}
69 
70 	argc -= optind;
71 	argv += optind;
72 
73 	fp = stdin;
74 	filename = "stdin";
75 	rval = 0;
76 	do {
77 		if (*argv) {
78 			if ((fp = fopen(*argv, "r")) == NULL) {
79 				warn("%s: %s", *argv, strerror(errno));
80 				rval = 1;
81 				++argv;
82 				continue;
83 			}
84 			filename = *argv++;
85 		}
86 		while (p = fgetline(fp, &len)) {
87 			t = p + len - 1;
88 			for (t = p + len - 1; t >= p; --t)
89 				putchar(*t);
90 			putchar('\n');
91 		}
92 		if (ferror(fp)) {
93 			warn("%s: %s", filename, strerror(errno));
94 			rval = 1;
95 		}
96 		(void)fclose(fp);
97 	} while(*argv);
98 	exit(rval);
99 }
100 
101 #if __STDC__
102 #include <stdarg.h>
103 #else
104 #include <varargs.h>
105 #endif
106 
107 void
108 #if __STDC__
109 warn(const char *fmt, ...)
110 #else
111 warn(fmt, va_alist)
112 	char *fmt;
113         va_dcl
114 #endif
115 {
116 	va_list ap;
117 #if __STDC__
118 	va_start(ap, fmt);
119 #else
120 	va_start(ap);
121 #endif
122 	(void)fprintf(stderr, "rev: ");
123 	(void)vfprintf(stderr, fmt, ap);
124 	va_end(ap);
125 	(void)fprintf(stderr, "\n");
126 }
127 
128 void
129 usage()
130 {
131 	(void)fprintf(stderr, "usage: rev [file ...]\n");
132 	exit(1);
133 }
134