tty.c revision 1.5 
1/*	$NetBSD: tty.c,v 1.5 1997/10/20 01:10:39 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. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <sys/cdefs.h>
37#ifndef lint
38__COPYRIGHT("@(#) Copyright (c) 1988, 1993\n\
39	The Regents of the University of California.  All rights reserved.\n");
40#endif /* not lint */
41
42#ifndef lint
43#if 0
44static char sccsid[] = "@(#)tty.c	8.1 (Berkeley) 6/6/93";
45#endif
46__RCSID("$NetBSD: tty.c,v 1.5 1997/10/20 01:10:39 lukem Exp $");
47#endif /* not lint */
48
49#include <stdio.h>
50#include <stdlib.h>
51#include <unistd.h>
52
53int	main __P((int, char **));
54static void usage	__P((void));
55
56int
57main(argc, argv)
58	int argc;
59	char **argv;
60{
61	int ch, sflag;
62	char *t;
63
64	sflag = 0;
65	while ((ch = getopt(argc, argv, "s")) != -1) {
66		switch((char)ch) {
67		case 's':
68			sflag = 1;
69			break;
70		case '?':
71		default:
72			usage();
73			/* NOTREACHED */
74		}
75	}
76
77	t = ttyname(STDIN_FILENO);
78	if (!sflag)
79		puts(t ? t : "not a tty");
80	exit(t ? 0 : 1);
81}
82
83
84static void
85usage ()
86{
87	fprintf(stderr, "usage: tty [-s]\n");
88	exit(2);
89}
90