kolibrios-fun/programs/develop/open watcom/trunk/clib/string/strncpy.c

112 lines
3.7 KiB
C
Raw Normal View History

/****************************************************************************
*
* 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: WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
* DESCRIBE IT HERE!
*
****************************************************************************/
#include "variety.h"
#include "widechar.h"
#include <string.h>
#include "riscstr.h"
#if defined(M_I86) & !defined(__WIDECHAR__)
extern char *fast_strncpy( char _WCFAR *, const char *, size_t );
#if defined(__SMALL_DATA__)
#pragma aux fast_strncpy = \
0x57 /* push di */\
0xac /* L1: lodsb */\
0xaa /* stosb */\
0x84 0xc0 /* test al,al */\
0xe0 0xfa /* loopne L1 */\
0x31 0xc0 /* xor ax,ax */\
0xd1 0xe9 /* shr cx,1 */\
0xf3 0xab /* rep stosw */\
0x11 0xc9 /* adc cx,cx */\
0xf3 0xaa /* rep stosb */\
0x58 /* pop ax */\
parm caller [es di] [si] [cx]\
value [ax] \
modify exact [ax cx si di];
#else
#pragma aux fast_strncpy = \
0x1e /* push ds */ \
0x8e 0xda /* mov ds,dx */ \
0x57 /* push di */\
0xac /* L1: lodsb */\
0xaa /* stosb */\
0x84 0xc0 /* test al,al */\
0xe0 0xfa /* loopne L1 */\
0x31 0xc0 /* xor ax,ax */\
0xd1 0xe9 /* shr cx,1 */\
0xf3 0xab /* rep stosw */\
0x11 0xc9 /* adc cx,cx */\
0xf3 0xaa /* rep stosb */\
0x58 /* pop ax */\
0x1f /* pop ds */ \
parm caller [es di] [dx si] [cx]\
value [es ax] \
modify exact [ax cx si di];
#endif
#endif
#if defined(__RISCSTR__) && defined(__WIDECHAR__)
_WCRTLINK CHAR_TYPE *__simple_wcsncpy( CHAR_TYPE *dst, const CHAR_TYPE *src, size_t len )
#else
_WCRTLINK CHAR_TYPE *__F_NAME(strncpy,wcsncpy)( CHAR_TYPE *dst, const CHAR_TYPE *src, size_t len )
#endif
{
#if defined(M_I86) && !defined(__WIDECHAR__)
if( len ) {
return( fast_strncpy( dst, src, len ) );
}
return( dst );
#else
CHAR_TYPE *ret;
ret = dst;
for(;len; --len ) {
if( *src == NULLCHAR ) break;
*dst++ = *src++;
}
while( len != 0 ) {
*dst++ = NULLCHAR; /* pad destination string with null chars */
--len;
}
return( ret );
#endif
}