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#include "lint.h"
33#include "file64.h"
34#include <stdio.h>
35#include <errno.h>
36#include <sys/types.h>
37#include "stdiom.h"
38
39#undef _wrtchk
40
41/* check permissions, correct for read & write changes */
42int
43_wrtchk(FILE *iop)
44{
45	if ((iop->_flag & (_IOWRT | _IOEOF)) != _IOWRT) {
46		if (!(iop->_flag & (_IOWRT | _IORW))) {
47			iop->_flag |= _IOERR;
48			errno = EBADF;
49			return (EOF); /* stream is not writeable */
50		}
51		iop->_flag = (iop->_flag & ~_IOEOF) | _IOWRT;
52	}
53
54	/* if first I/O to the stream get a buffer */
55	if (iop->_base == NULL && _findbuf(iop) == NULL)
56		return (EOF);
57	else if ((iop->_ptr == iop->_base) &&
58	    !(iop->_flag & (_IOLBF | _IONBF))) {
59		iop->_cnt = _bufend(iop) - iop->_ptr;
60	}
61	return (0);
62}
63