mbsnset.cpp File Reference

#include <corecrt_internal_mbstring.h>
#include <locale.h>
#include <string.h>

Include dependency graph for mbsnset.cpp:

Go to the source code of this file.

Functions
unsigned char *__cdecl	_mbsnset_l (unsigned char *string, unsigned int val, size_t count, _locale_t plocinfo)
unsigned char *__cdecl	_mbsnset (unsigned char *string, unsigned int val, size_t count)

Function Documentation

_mbsnset()

unsigned char *__cdecl _mbsnset	(	unsigned char *	string,
		unsigned int	val,
		size_t	count
	)

Definition at line 134 of file mbsnset.cpp.

{
_BEGIN_SECURE_CRT_DEPRECATION_DISABLE
    return _mbsnset_l(string, val, count, nullptr);
_END_SECURE_CRT_DEPRECATION_DISABLE
}

_mbsnset_l()

unsigned char *__cdecl _mbsnset_l	(	unsigned char *	string,
		unsigned int	val,
		size_t	count,
		_locale_t	plocinfo
	)

Definition at line 57 of file mbsnset.cpp.

{
        unsigned char  *start = string;
        unsigned int leadbyte = 0;
        unsigned char highval, lowval;
        _LocaleUpdate _loc_update(plocinfo);
 
        /* validation section */
        _VALIDATE_RETURN(string != nullptr || count == 0, EINVAL, nullptr);
 
        /*
         * leadbyte flag indicates if the last byte we overwrote was
         * a lead byte or not.
         */
_BEGIN_SECURE_CRT_DEPRECATION_DISABLE
        if (_loc_update.GetLocaleT()->mbcinfo->ismbcodepage == 0)
            return (unsigned char *)_strnset((char *)string, val, count);
_END_SECURE_CRT_DEPRECATION_DISABLE
 
        highval = static_cast<unsigned char>(val >> 8);
        if (highval != 0)
        {
 
            /* double byte value */
 
            lowval = (unsigned char)(val & 0x00ff);
 
            if(lowval=='\0')
            {
                _ASSERTE(("invalid MBCS pair passed to mbsnset",0));
 
                /* Ideally we would return nullptr here and signal an error
                    condition. But since this function has no other
                    error modes, there would be a good chance of crashing
                    the caller. So instead we fill the string with spaces
                    to ensure that no information leaks through
                    unexpectedly. Anyway, we do set errno to EINVAL.
                */
                errno = EINVAL;
                lowval=highval=' ';
            }
 
            while (count-- && *string) {
                leadbyte = _ismbbtruelead_l(leadbyte, *string, _loc_update.GetLocaleT());
                *string++ = highval;
 
                if (*string) {
                    leadbyte = _ismbbtruelead_l(leadbyte, *string, _loc_update.GetLocaleT());
                    *string++ = lowval;
                }
                else
                    /* overwrite orphaned highval byte */
                    *(string-1) = ' ';
            }
        }
 
        else {
            /* single byte value */
 
            while (count-- && *string) {
                leadbyte = _ismbbtruelead_l(leadbyte, *string, _loc_update.GetLocaleT());
                *string++ = (unsigned char)val;
            }
        }
 
        /* overwrite orphaned trailing byte, if necessary */
        if(leadbyte && *string)
            *string = ' ';
 
        return( start );
}

Referenced by _mbsnset().