xref: /openbsd/usr.bin/biff/biff.c (revision 09467b48)
1 /*	$OpenBSD: biff.c,v 1.17 2019/06/28 13:35:00 deraadt Exp $	*/
2 /*	$NetBSD: biff.c,v 1.3 1995/03/26 02:34:22 glass Exp $	*/
3 
4 /*
5  * Copyright (c) 1980, 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 #include <sys/stat.h>
35 
36 #include <err.h>
37 #include <errno.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 static void usage(void);
44 
45 int
46 main(int argc, char *argv[])
47 {
48 	struct stat sb;
49 	int ch;
50 	char *name;
51 
52 	while ((ch = getopt(argc, argv, "")) != -1)
53 		switch(ch) {
54 		case '?':
55 		default:
56 			usage();
57 		}
58 	argc -= optind;
59 	argv += optind;
60 
61 	if ((name = ttyname(STDERR_FILENO)) == NULL)
62 		err(2, "tty");
63 
64 	if (unveil(name, "rw") == -1)
65 		err(2, "unveil");
66 	if (pledge("stdio rpath fattr", NULL) == -1)
67 		err(2, "pledge");
68 
69 	if (stat(name, &sb))
70 		err(2, "stat");
71 
72 	sb.st_mode &= ACCESSPERMS;
73 
74 	if (*argv == NULL) {
75 		(void)printf("is %s\n", sb.st_mode & S_IXUSR ? "y" : "n");
76 		exit(sb.st_mode & S_IXUSR ? 0 : 1);
77 	}
78 
79 	switch(argv[0][0]) {
80 	case 'n':
81 		if (chmod(name, sb.st_mode & ~S_IXUSR) == -1)
82 			err(2, "%s", name);
83 		break;
84 	case 'y':
85 		if (chmod(name, sb.st_mode | S_IXUSR) == -1)
86 			err(2, "%s", name);
87 		break;
88 	default:
89 		usage();
90 	}
91 	exit(sb.st_mode & S_IXUSR ? 0 : 1);
92 }
93 
94 static void
95 usage(void)
96 {
97 	(void)fprintf(stderr, "usage: biff [n | y]\n");
98 	exit(2);
99 }
100