Files
harbour-core/harbour/source/tools/ctchksum.c
2000-03-21 11:51:27 +00:00

53 lines
1.8 KiB
C

/*
* $Id$
*/
/*
* Harbour Project source code:
* CT_CHECKSUM() CA-Tools function
*
* Copyright 1999 Victor Szakats <info@szelvesz.hu>
* www - http://www.harbour-project.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version, with one exception:
*
* The exception is that if you link the Harbour Runtime Library (HRL)
* and/or the Harbour Virtual Machine (HVM) with other files to produce
* an executable, this does not by itself cause the resulting executable
* to be covered by the GNU General Public License. Your use of that
* executable is in no way restricted on account of linking the HRL
* and/or HVM code into it.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA (or visit
* their web site at http://www.gnu.org/).
*
*/
#include "hbapi.h"
HB_FUNC( CT_CHECKSUM )
{
BYTE * pbyString = ( BYTE * ) hb_parc( 1 );
ULONG ulLen = hb_parclen( 1 );
ULONG ulPos;
ULONG ulResult = 0;
for( ulPos = 0; ulPos < ulLen; ulPos++ )
ulResult += ( ( ULONG ) ( pbyString[ ulPos ] + ( ULONG ) ( pbyString[ ulPos + 1 ] * 256 ) ) ) & 0xFFFF;
/* NOTE: Using hb_retnd() instead of hb_retnl() to always return a
positive value. */
hb_retnd( ( ULONG ) ( ( ulResult & 0x00FFFFFF ) | ( ( ulLen & 0xFF ) << 24 ) ) );
}