/*
 * 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 1986 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"  /* from S5R2 1.2 */

/*LINTLIBRARY*/
/*
 * Return file offset.
 * Coordinates with buffering.
 */
#include <stdio.h>

extern long lseek();

long
ftell(iop)
register FILE *iop;
{
	register long tres;
	register int adjust;

	if(iop->_cnt < 0)
		iop->_cnt = 0;
	if(iop->_flag & _IOREAD)
		adjust = - iop->_cnt;
	else if(iop->_flag & (_IOWRT | _IORW)) {
		adjust = 0;
		if(iop->_flag & _IOWRT && iop->_base &&
					(iop->_flag & _IONBF) == 0)
			adjust = iop->_ptr - iop->_base;
	} else
		return(-1);
	tres = lseek(fileno(iop), 0L, 1);
	if(tres >= 0)
		tres += (long)adjust;
	return(tres);
}