/*** *mbsnbcat.c - concatenate string2 onto string1, max length n bytes * * Copyright (c) 1985-1997, Microsoft Corporation. All rights reserved. * *Purpose: * defines mbsnbcat() - concatenate maximum of n bytes * *******************************************************************************/ #ifdef _MBCS #include #include #include #include #include #include #define _MBSBTYPE(str,len) _mbsbtype(str,len) /*** * _mbsnbcat - concatenate max cnt bytes onto dst * *Purpose: * Concatenates src onto dst, with a maximum of cnt bytes copied. * Handles 2-byte MBCS characters correctly. * *Entry: * unsigned char *dst - string to concatenate onto * unsigned char *src - string to concatenate from * int cnt - number of bytes to copy * *Exit: * returns dst, with src (at least part) concatenated on * *Exceptions: * *******************************************************************************/ unsigned char * __cdecl _mbsnbcat( unsigned char *dst, const unsigned char *src, size_t cnt ) { unsigned char *start; if (!cnt) return(dst); if ( _ISNOTMBCP ) return strncat(dst, src, cnt); _mlock(_MB_CP_LOCK); start = dst; while (*dst++) ; --dst; // dst now points to end of dst string /* if last char in string is a lead byte, back up pointer */ if (_MBSBTYPE(start, (int) ((dst - start) - 1)) == _MBC_LEAD) --dst; /* copy over the characters */ while (cnt--) { if (_ISLEADBYTE(*src)) { *dst++ = *src++; if (!cnt--) { /* write nul if cnt exhausted */ dst[-1] = '\0'; break; } if ((*dst++ = *src++)=='\0') { /* or if no trail byte */ dst[-2] = '\0'; break; } } else if ((*dst++ = *src++) == '\0') break; } /* enter final nul, if necessary */ if (_MBSBTYPE(start, (int) ((dst - start) - 1)) == _MBC_LEAD) dst[-1] = '\0'; else *dst = '\0'; _munlock(_MB_CP_LOCK); return(start); } #endif /* _MBCS */