windows-nt/Source/XPSP1/NT/base/crts/crtw32/mbstring/mbsncpy.c
2020-09-26 16:20:57 +08:00

102 lines
2.5 KiB
C

/***
*mbsncpy.c - Copy one string to another, n chars only (MBCS)
*
* Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Copy one string to another, n chars only (MBCS)
*
*Revision History:
* 11-19-92 KRS Ported from 16-bit sources.
* 08-03-93 KRS Fix logic bug.
* 10-05-93 GJF Replaced _CRTAPI1 with __cdecl.
* 04-15-93 CFW Add _MB_CP_LOCK.
* 05-09-94 CFW Optimize for SBCS.
* 05-19-94 CFW Enable non-Win32.
* 09-11-97 GJF Replaced __mbcodepage == 0 with _ISNOTMBCP.
* 04-16-98 GJF Revised multithread support based on threadmbcinfo
* structs
*
*******************************************************************************/
#ifdef _MBCS
#include <mtdll.h>
#include <cruntime.h>
#include <string.h>
#include <mbdata.h>
#include <mbctype.h>
#include <mbstring.h>
/***
* _mbsncpy - Copy one string to another, n chars only (MBCS)
*
*Purpose:
* Copies exactly cnt character from src to dst. If strlen(src) < cnt, the
* remaining character are padded with null bytes. If strlen >= cnt, no
* terminating null byte is added. 2-byte MBCS characters are handled
* correctly.
*
*Entry:
* unsigned char *dst = destination for copy
* unsigned char *src = source for copy
* int cnt = number of characters to copy
*
*Exit:
* returns dst = destination of copy
*
*Exceptions:
*
*******************************************************************************/
unsigned char * __cdecl _mbsncpy(
unsigned char *dst,
const unsigned char *src,
size_t cnt
)
{
unsigned char *start = dst;
#ifdef _MT
pthreadmbcinfo ptmbci = _getptd()->ptmbcinfo;
if ( ptmbci != __ptmbcinfo )
ptmbci = __updatetmbcinfo();
if ( _ISNOTMBCP_MT(ptmbci) )
#else
if ( _ISNOTMBCP )
#endif
return strncpy(dst, src, cnt);
while (cnt) {
cnt--;
#ifdef _MT
if ( __ismbblead_mt(ptmbci, *src) ) {
#else
if ( _ismbblead(*src) ) {
#endif
*dst++ = *src++;
if ((*dst++ = *src++) == '\0') {
dst[-2] = '\0';
break;
}
}
else
if ((*dst++ = *src++) == '\0')
break;
}
/* pad with nulls as needed */
while (cnt--)
*dst++ = '\0';
return start;
}
#endif /* _MBCS */