mbbtype.c

C标准库源代码

/***
*mbbtype.c - Return type of byte based on previous byte (MBCS)
*
*       Copyright (c) 1985-1997, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       Return type of byte based on previous byte (MBCS)
*
*******************************************************************************/

#ifdef _MBCS

#include <cruntime.h>
#include <mbdata.h>
#include <mbctype.h>
#include <mbstring.h>

/***
*int _mbbtype(c, ctype) - Return type of byte based on previous byte (MBCS)
*
*Purpose:
*       Returns type of supplied byte.  This decision is context
*       sensitive so a control test condition is supplied.  Normally,
*       this is the type of the previous byte in the string.
*
*Entry:
*       unsigned char c = character to be checked
*       int ctype = control test condition (i.e., type of previous char)
*
*Exit:
*       _MBC_LEAD      = if 1st byte of MBCS char
*       _MBC_TRAIL     = if 2nd byte of MBCS char
*       _MBC_SINGLE    = valid single byte char
*
*       _MBC_ILLEGAL   = if illegal char
*
*Exceptions:
*
*******************************************************************************/

int __cdecl _mbbtype(
    unsigned char c,
    int ctype
    )
{

        switch(ctype) {

        case(_MBC_LEAD):
                if (_ISTRAILBYTE(c))
                        return(_MBC_TRAIL);
                else
                        return(_MBC_ILLEGAL);

        case(_MBC_TRAIL):
        case(_MBC_SINGLE):
        case(_MBC_ILLEGAL):
        default:
                if (_ISLEADBYTE(c))
                        return(_MBC_LEAD);
                else if (_ismbbprint(c))
                        return(_MBC_SINGLE);
                else
                        return(_MBC_ILLEGAL);


        }

}

#endif  /* _MBCS */