tty.c revision 1.7 
1/*	$NetBSD: tty.c,v 1.7 2008/07/21 14:19:27 lukem Exp $	*/
2
3/*
4 * Copyright (c) 1988, 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/cdefs.h>
33#ifndef lint
34__COPYRIGHT("@(#) Copyright (c) 1988, 1993\
35 The Regents of the University of California.  All rights reserved.");
36#endif /* not lint */
37
38#ifndef lint
39#if 0
40static char sccsid[] = "@(#)tty.c	8.1 (Berkeley) 6/6/93";
41#endif
42__RCSID("$NetBSD: tty.c,v 1.7 2008/07/21 14:19:27 lukem Exp $");
43#endif /* not lint */
44
45#include <stdio.h>
46#include <stdlib.h>
47#include <unistd.h>
48
49int	main __P((int, char **));
50static void usage	__P((void));
51
52int
53main(argc, argv)
54	int argc;
55	char **argv;
56{
57	int ch, sflag;
58	char *t;
59
60	sflag = 0;
61	while ((ch = getopt(argc, argv, "s")) != -1) {
62		switch((char)ch) {
63		case 's':
64			sflag = 1;
65			break;
66		case '?':
67		default:
68			usage();
69			/* NOTREACHED */
70		}
71	}
72
73	t = ttyname(STDIN_FILENO);
74	if (!sflag)
75		puts(t ? t : "not a tty");
76	exit(t ? 0 : 1);
77}
78
79
80static void
81usage ()
82{
83	fprintf(stderr, "usage: tty [-s]\n");
84	exit(2);
85}
86