xref: /openbsd-src/usr.bin/rev/rev.c (revision f6aab3d83b51b91c24247ad2c2573574de475a82)
1 /*	$OpenBSD: rev.c,v 1.16 2022/02/08 17:44:18 cheloha 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 <locale.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 int multibyte;
44 
45 int isu8cont(unsigned char);
46 int rev_file(const char *);
47 void usage(void);
48 
49 int
50 main(int argc, char *argv[])
51 {
52 	int ch, rval;
53 
54 	setlocale(LC_CTYPE, "");
55 	multibyte = MB_CUR_MAX > 1;
56 
57 	if (pledge("stdio rpath", NULL) == -1)
58 		err(1, "pledge");
59 
60 	while ((ch = getopt(argc, argv, "")) != -1)
61 		switch(ch) {
62 		default:
63 			usage();
64 		}
65 
66 	argc -= optind;
67 	argv += optind;
68 
69 	rval = 0;
70 	if (argc == 0) {
71 		if (pledge("stdio", NULL) == -1)
72 			err(1, "pledge");
73 
74 		rval = rev_file(NULL);
75 	} else {
76 		for (; *argv != NULL; argv++)
77 			rval |= rev_file(*argv);
78 	}
79 	return rval;
80 }
81 
82 int
83 isu8cont(unsigned char c)
84 {
85 	return (c & (0x80 | 0x40)) == 0x80;
86 }
87 
88 int
89 rev_file(const char *path)
90 {
91 	char *p = NULL, *t, *te, *u;
92 	const char *filename;
93 	FILE *fp;
94 	size_t ps = 0;
95 	ssize_t len;
96 	int rval = 0;
97 
98 	if (path != NULL) {
99 		fp = fopen(path, "r");
100 		if (fp == NULL) {
101 			warn("%s", path);
102 			return 1;
103 		}
104 		filename = path;
105 	} else {
106 		fp = stdin;
107 		filename = "stdin";
108 	}
109 
110 	while ((len = getline(&p, &ps, fp)) != -1) {
111 		if (p[len - 1] == '\n')
112 			--len;
113 		for (t = p + len - 1; t >= p; --t) {
114 			te = t;
115 			if (multibyte)
116 				while (t > p && isu8cont(*t))
117 					--t;
118 			for (u = t; u <= te; ++u)
119 				if (putchar(*u) == EOF)
120 					err(1, "stdout");
121 		}
122 		if (putchar('\n') == EOF)
123 			err(1, "stdout");
124 	}
125 	free(p);
126 	if (ferror(fp)) {
127 		warn("%s", filename);
128 		rval = 1;
129 	}
130 
131 	(void)fclose(fp);
132 
133 	return rval;
134 }
135 
136 void
137 usage(void)
138 {
139 	extern char *__progname;
140 
141 	(void)fprintf(stderr, "usage: %s [file ...]\n", __progname);
142 	exit(1);
143 }
144