xref: /titanic_44/usr/src/lib/libbc/libc/stdio/sys5/filbuf.c (revision 5d54f3d8999eac1762fe0a8c7177d20f1f201fae)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 1998 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984 AT&T */
/*        All Rights Reserved   */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*LINTLIBRARY*/
#include <stdio.h>
#include <unistd.h>

extern void	_findbuf();

static void	lbfflush(FILE *);

int
__filbuf(FILE *iop)
{
	return (_filbuf(iop));
}

int
_filbuf(FILE *iop)
{
	if ( !(iop->_flag & _IOREAD) )
		if (iop->_flag & _IORW)
			iop->_flag |= _IOREAD;
		else
			return(EOF);

	if (iop->_flag&_IOSTRG)
		return(EOF);

	if (iop->_base == NULL)  /* get buffer if we don't have one */
		_findbuf(iop);

	/* if this device is a terminal (line-buffered) or unbuffered, then */
	/* flush buffers of all line-buffered devices currently writing */

	if (iop->_flag & (_IOLBF | _IONBF))
		_fwalk(lbfflush);

	iop->_ptr = iop->_base;
	iop->_cnt = read(fileno(iop), (char *)iop->_base,
	    (unsigned)((iop->_flag & _IONBF) ? 1 : iop->_bufsiz ));
	if (--iop->_cnt >= 0)		/* success */
		return (*iop->_ptr++);
	if (iop->_cnt != -1)		/* error */
		iop->_flag |= _IOERR;
	else {				/* end-of-file */
		iop->_flag |= _IOEOF;
		if (iop->_flag & _IORW)
			iop->_flag &= ~_IOREAD;
	}
	iop->_cnt = 0;
	return (EOF);
}

static void
lbfflush(FILE *iop)
{
	if (iop->_flag & _IOLBF)
		(void) fflush(iop);
}