ftell.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* 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);
}