xref: /illumos-gate/usr/src/lib/libc/port/gen/isatty.c (revision fc1821fee2e1f208a4b5ff3e229e97b87979208a)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 
33 #pragma weak isatty = _isatty
34 
35 #include "synonyms.h"
36 #include <sys/types.h>
37 #include <sys/termio.h>
38 #include <errno.h>
39 #include <unistd.h>
40 
41 /*
42  * Returns 1 iff file is a tty
43  */
44 int
45 isatty(int f)
46 {
47 	struct termio tty;
48 	int err;
49 
50 	err = errno;
51 	if (ioctl(f, TCGETA, &tty) < 0) {
52 		errno = err;
53 		return (0);
54 	}
55 	return (1);
56 }
57