xref: /freebsd/usr.bin/biff/biff.c (revision 5f4c09dd85bff675e0ca63c55ea3c517e0fddfcc)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1980, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1980, 1993\n\
35 	The Regents of the University of California.  All rights reserved.\n";
36 #endif
37 
38 #if 0
39 #ifndef lint
40 static char sccsid[] = "@(#)biff.c	8.1 (Berkeley) 6/6/93";
41 #endif
42 #endif
43 
44 #include <sys/cdefs.h>
45 #include <sys/stat.h>
46 
47 #include <err.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <unistd.h>
51 
52 static void usage(void) __dead2;
53 
54 int
55 main(int argc, char *argv[])
56 {
57 	struct stat sb;
58 	int ch;
59 	char *name;
60 
61 
62 	while ((ch = getopt(argc, argv, "")) != -1)
63 		switch(ch) {
64 		case '?':
65 		default:
66 			usage();
67 		}
68 	argc -= optind;
69 	argv += optind;
70 
71 	if ((name = ttyname(STDIN_FILENO)) == NULL &&
72 	    (name = ttyname(STDOUT_FILENO)) == NULL &&
73 	    (name = ttyname(STDERR_FILENO)) == NULL)
74 		err(2, "unknown tty");
75 
76 	if (stat(name, &sb))
77 		err(2, "stat");
78 
79 	if (*argv == NULL) {
80 		(void)printf("is %s\n",
81 		    sb.st_mode & S_IXUSR ? "y" :
82 		    sb.st_mode & S_IXGRP ? "b" : "n");
83 		return (sb.st_mode & (S_IXUSR | S_IXGRP) ? 0 : 1);
84 
85 	}
86 
87 	switch (argv[0][0]) {
88 	case 'n':
89 		if (chmod(name, sb.st_mode & ~(S_IXUSR | S_IXGRP)) < 0)
90 			err(2, "%s", name);
91 		break;
92 	case 'y':
93 		if (chmod(name, (sb.st_mode & ~(S_IXUSR | S_IXGRP)) | S_IXUSR)
94 		    < 0)
95 			err(2, "%s", name);
96 		break;
97 	case 'b':
98 		if (chmod(name, (sb.st_mode & ~(S_IXUSR | S_IXGRP)) | S_IXGRP)
99 		    < 0)
100 			err(2, "%s", name);
101 		break;
102 	default:
103 		usage();
104 	}
105 	return (sb.st_mode & (S_IXUSR | S_IXGRP) ? 0 : 1);
106 }
107 
108 static void
109 usage(void)
110 {
111 	(void)fprintf(stderr, "usage: biff [n | y | b]\n");
112 	exit(2);
113 }
114