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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/*	Copyright (c) 1988 AT&T	*/
28/*	  All Rights Reserved  	*/
29
30#pragma ident	"%Z%%M%	%I%	%E% SMI"
31
32/*
33 * Check to see if a file descriptor is that of a stream.
34 * Return 1 with errno set to 0 if it is. Otherwise,
35 * return 0 with errno set to 0.
36 * The only error returned is that case of a bad file desc.
37 *
38 */
39
40#pragma weak _isastream = isastream
41
42#include "lint.h"
43#include <sys/types.h>
44#include <stdio.h>
45#include <errno.h>
46#include <stropts.h>
47
48int
49isastream(int fd)
50{
51	int rval;
52
53	rval = ioctl(fd, I_CANPUT, 0);
54	if (rval == -1 && errno == EBADF)
55		return (-1);
56
57	errno = 0;
58	if (rval == 0 || rval == 1)
59		return (1);
60
61	return (0);
62}
63