xref: /titanic_50/usr/src/lib/libc/port/gen/isastream.c (revision 3d729aecc03ea6ebb9bd5d56b8dccd24f57daa41)
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 
48 int
49 isastream(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