xref: /freebsd/usr.bin/biff/biff.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
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 #include <sys/stat.h>
33 
34 #include <err.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <unistd.h>
38 
39 static void usage(void) __dead2;
40 
41 int
42 main(int argc, char *argv[])
43 {
44 	struct stat sb;
45 	int ch;
46 	char *name;
47 
48 
49 	while ((ch = getopt(argc, argv, "")) != -1)
50 		switch(ch) {
51 		case '?':
52 		default:
53 			usage();
54 		}
55 	argc -= optind;
56 	argv += optind;
57 
58 	if ((name = ttyname(STDIN_FILENO)) == NULL &&
59 	    (name = ttyname(STDOUT_FILENO)) == NULL &&
60 	    (name = ttyname(STDERR_FILENO)) == NULL)
61 		err(2, "unknown tty");
62 
63 	if (stat(name, &sb))
64 		err(2, "stat");
65 
66 	if (*argv == NULL) {
67 		(void)printf("is %s\n",
68 		    sb.st_mode & S_IXUSR ? "y" :
69 		    sb.st_mode & S_IXGRP ? "b" : "n");
70 		return (sb.st_mode & (S_IXUSR | S_IXGRP) ? 0 : 1);
71 
72 	}
73 
74 	switch (argv[0][0]) {
75 	case 'n':
76 		if (chmod(name, sb.st_mode & ~(S_IXUSR | S_IXGRP)) < 0)
77 			err(2, "%s", name);
78 		break;
79 	case 'y':
80 		if (chmod(name, (sb.st_mode & ~(S_IXUSR | S_IXGRP)) | S_IXUSR)
81 		    < 0)
82 			err(2, "%s", name);
83 		break;
84 	case 'b':
85 		if (chmod(name, (sb.st_mode & ~(S_IXUSR | S_IXGRP)) | S_IXGRP)
86 		    < 0)
87 			err(2, "%s", name);
88 		break;
89 	default:
90 		usage();
91 	}
92 	return (sb.st_mode & (S_IXUSR | S_IXGRP) ? 0 : 1);
93 }
94 
95 static void
96 usage(void)
97 {
98 	(void)fprintf(stderr, "usage: biff [n | y | b]\n");
99 	exit(2);
100 }
101