1 /* $OpenBSD: tty.c,v 1.14 2024/05/06 16:49:46 cheloha Exp $ */
2 /* $NetBSD: tty.c,v 1.4 1994/12/07 00:46:57 jtc Exp $ */
3
4 /*
5 * Copyright (c) 1988, 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 <stdio.h>
34 #include <stdlib.h>
35 #include <unistd.h>
36 #include <paths.h>
37 #include <err.h>
38
39 static void usage(void);
40
41 int
main(int argc,char * argv[])42 main(int argc, char *argv[])
43 {
44 int ch, sflag;
45 char *t;
46
47 sflag = 0;
48 while ((ch = getopt(argc, argv, "s")) != -1) {
49 switch(ch) {
50 case 's':
51 sflag = 1;
52 break;
53 default:
54 usage();
55 /* NOTREACHED */
56 }
57 }
58
59 if (unveil(_PATH_DEVDB, "r") == -1)
60 err(2, "unveil %s", _PATH_DEVDB);
61 if (pledge("stdio rpath", NULL) == -1)
62 err(2, "pledge");
63
64 t = ttyname(STDIN_FILENO);
65 if (!sflag)
66 puts(t ? t : "not a tty");
67 exit(t ? 0 : 1);
68 }
69
70 static void
usage(void)71 usage(void)
72 {
73 fprintf(stderr, "usage: tty [-s]\n");
74 exit(2);
75 }
76