_wrtchk.c revision 7c478bd95313f5f23a4c958a745db2134aa0324
17c478bdstevel@tonic-gate/*
27c478bdstevel@tonic-gate * CDDL HEADER START
37c478bdstevel@tonic-gate *
47c478bdstevel@tonic-gate * The contents of this file are subject to the terms of the
57c478bdstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only
67c478bdstevel@tonic-gate * (the "License").  You may not use this file except in compliance
77c478bdstevel@tonic-gate * with the License.
87c478bdstevel@tonic-gate *
97c478bdstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
107c478bdstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
117c478bdstevel@tonic-gate * See the License for the specific language governing permissions
127c478bdstevel@tonic-gate * and limitations under the License.
137c478bdstevel@tonic-gate *
147c478bdstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
157c478bdstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
167c478bdstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
177c478bdstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
187c478bdstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
197c478bdstevel@tonic-gate *
207c478bdstevel@tonic-gate * CDDL HEADER END
217c478bdstevel@tonic-gate */
227c478bdstevel@tonic-gate/*
237c478bdstevel@tonic-gate * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
247c478bdstevel@tonic-gate * Use is subject to license terms.
257c478bdstevel@tonic-gate */
267c478bdstevel@tonic-gate
277c478bdstevel@tonic-gate#pragma ident	"%Z%%M%	%I%	%E% SMI"
287c478bdstevel@tonic-gate
297c478bdstevel@tonic-gate/*	Copyright (c) 1988 AT&T	*/
307c478bdstevel@tonic-gate/*	  All Rights Reserved  	*/
317c478bdstevel@tonic-gate
327c478bdstevel@tonic-gate
337c478bdstevel@tonic-gate#include "synonyms.h"
347c478bdstevel@tonic-gate#include "file64.h"
357c478bdstevel@tonic-gate#include <stdio.h>
367c478bdstevel@tonic-gate#include <errno.h>
377c478bdstevel@tonic-gate#include <sys/types.h>
387c478bdstevel@tonic-gate#include "stdiom.h"
397c478bdstevel@tonic-gate
407c478bdstevel@tonic-gate#undef _wrtchk
417c478bdstevel@tonic-gate
427c478bdstevel@tonic-gate/* check permissions, correct for read & write changes */
437c478bdstevel@tonic-gateint
447c478bdstevel@tonic-gate_wrtchk(FILE *iop)
457c478bdstevel@tonic-gate{
467c478bdstevel@tonic-gate	if ((iop->_flag & (_IOWRT | _IOEOF)) != _IOWRT) {
477c478bdstevel@tonic-gate		if (!(iop->_flag & (_IOWRT | _IORW))) {
487c478bdstevel@tonic-gate			iop->_flag |= _IOERR;
497c478bdstevel@tonic-gate			errno = EBADF;
507c478bdstevel@tonic-gate			return (EOF); /* stream is not writeable */
517c478bdstevel@tonic-gate		}
527c478bdstevel@tonic-gate		iop->_flag = (iop->_flag & ~_IOEOF) | _IOWRT;
537c478bdstevel@tonic-gate	}
547c478bdstevel@tonic-gate
557c478bdstevel@tonic-gate	/* if first I/O to the stream get a buffer */
567c478bdstevel@tonic-gate	if (iop->_base == NULL && _findbuf(iop) == NULL)
577c478bdstevel@tonic-gate		return (EOF);
587c478bdstevel@tonic-gate	else if ((iop->_ptr == iop->_base) &&
597c478bdstevel@tonic-gate	    !(iop->_flag & (_IOLBF | _IONBF))) {
607c478bdstevel@tonic-gate		iop->_cnt = _bufend(iop) - iop->_ptr;
617c478bdstevel@tonic-gate	}
627c478bdstevel@tonic-gate	return (0);
637c478bdstevel@tonic-gate}
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