kolibrios-fun/programs/develop/open watcom/trunk/clib/streamio/ftell.c

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/****************************************************************************
*
* Open Watcom Project
*
* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
* ========================================================================
*
* This file contains Original Code and/or Modifications of Original
* Code as defined in and that are subject to the Sybase Open Watcom
* Public License version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
* provided with the Original Code and Modifications, and is also
* available at www.sybase.com/developer/opensource.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
* NON-INFRINGEMENT. Please see the License for the specific language
* governing rights and limitations under the License.
*
* ========================================================================
*
* Description: Platform independent ftell() implementaiton.
*
****************************************************************************/
#include "variety.h"
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "fileacc.h"
_WCRTLINK long ftell( FILE *fp )
{
long pos;
_ValidFile( fp, -1 );
if( fp->_flag & _APPEND && fp->_flag & _DIRTY ) {
fflush( fp ); /* if data written in append mode, OS must know */
}
pos = tell( fileno( fp ) );
if( pos == -1 ) {
return( -1L );
}
_AccessFile( fp );
if( fp->_cnt != 0 ) { /* if something in buffer */
if( fp->_flag & _DIRTY ) { /* last operation was a put */
pos += fp->_cnt;
} else { /* last operation was a get */
pos -= fp->_cnt;
}
}
_ReleaseFile( fp );
return( pos );
}