xref: /netbsd-src/usr.bin/rev/rev.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
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[] = "from: @(#)rev.c	5.2 (Berkeley) 3/21/92";*/
42 static char rcsid[] = "$Id: rev.c,v 1.4 1994/01/04 05:24:10 cgd Exp $";
43 #endif /* not lint */
44 
45 #include <sys/types.h>
46 #include <errno.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 
51 void usage __P((void));
52 void warn __P((const char *, ...));
53 
54 int
55 main(argc, argv)
56 	int argc;
57 	char *argv[];
58 {
59 	register char *filename, *p, *t;
60 	FILE *fp;
61 	size_t len;
62 	int ch, rval;
63 
64 	while ((ch = getopt(argc, argv, "")) != EOF)
65 		switch(ch) {
66 		case '?':
67 		default:
68 			usage();
69 		}
70 
71 	argc -= optind;
72 	argv += optind;
73 
74 	fp = stdin;
75 	filename = "stdin";
76 	rval = 0;
77 	do {
78 		if (*argv) {
79 			if ((fp = fopen(*argv, "r")) == NULL) {
80 				warn("%s: %s", *argv, strerror(errno));
81 				rval = 1;
82 				++argv;
83 				continue;
84 			}
85 			filename = *argv++;
86 		}
87 		while (p = fgetln(fp, &len)) {
88 			if (p[len-1] == '\n')
89 				--len;
90 			t = p + len - 1;
91 			for (t = p + len - 1; t >= p; --t)
92 				putchar(*t);
93 			putchar('\n');
94 		}
95 		if (ferror(fp)) {
96 			warn("%s: %s", filename, strerror(errno));
97 			rval = 1;
98 		}
99 		(void)fclose(fp);
100 	} while(*argv);
101 	exit(rval);
102 }
103 
104 #if __STDC__
105 #include <stdarg.h>
106 #else
107 #include <varargs.h>
108 #endif
109 
110 void
111 #if __STDC__
112 warn(const char *fmt, ...)
113 #else
114 warn(fmt, va_alist)
115 	char *fmt;
116         va_dcl
117 #endif
118 {
119 	va_list ap;
120 #if __STDC__
121 	va_start(ap, fmt);
122 #else
123 	va_start(ap);
124 #endif
125 	(void)fprintf(stderr, "rev: ");
126 	(void)vfprintf(stderr, fmt, ap);
127 	va_end(ap);
128 	(void)fprintf(stderr, "\n");
129 }
130 
131 void
132 usage()
133 {
134 	(void)fprintf(stderr, "usage: rev [file ...]\n");
135 	exit(1);
136 }
137