mbsrev.cpp File Reference

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

Include dependency graph for mbsrev.cpp:

Go to the source code of this file.

Functions
unsigned char *__cdecl	_mbsrev_l (unsigned char *string, _locale_t plocinfo)
unsigned char *__cdecl	_mbsrev (unsigned char *string)

Function Documentation

_mbsrev()

unsigned char *__cdecl _mbsrev

(

unsigned char *

string

)

Definition at line 103 of file mbsrev.cpp.

{
    return _mbsrev_l(string, nullptr);
}

_mbsrev_l()

unsigned char *__cdecl _mbsrev_l	(	unsigned char *	string,
		_locale_t	plocinfo
	)

Definition at line 38 of file mbsrev.cpp.

{
        unsigned char *start = string;
        unsigned char *left  = string;
        unsigned char c;
        _LocaleUpdate _loc_update(plocinfo);
 
        /* validation section */
        _VALIDATE_RETURN(string != nullptr, EINVAL, nullptr);
 
        if (_loc_update.GetLocaleT()->mbcinfo->ismbcodepage == 0)
            return (unsigned char *)_strrev((char *)string);
 
 
        /* first go through and reverse the bytes in MBCS chars */
        while ( *string ) {
            if ( _ismbblead_l(*string++, _loc_update.GetLocaleT()) ) {
                if ( *string ) {
                    c = *string;
                    *string = *(string - 1);
                    *(string - 1) = c;
                    string++;
                }
                else
                {
                    /*  second byte is EOS
                        There is nothing really satisfying to do here. We have a string
                        that ends in leadbyte,'\0'. Reversing this would lead to the leadbyte
                        becoming falsely attached to the character before it:
                        (XL0 -> LX0, X has suddenly become a trailbyte)
 
                        So what we choose to do is assert and purge the dud byte from within the
                        string.
                    */
                    errno = EINVAL;
                    _ASSERTE(("Bad MBCS string passed into _mbsrev",0));
 
                    /* String has at least moved once already, so this is safe */
                    _ASSERTE(string>start);
 
                    /* move back one to point at the dud leadbyte */
                    --string;
 
                    /* now truncate the string one byte earlier */
                    *string='\0';
 
                    break;
                }
            }
        }
 
        /* now reverse the whole string */
        string--;
        while ( left < string ) {
            c = *left;
            *left++ = *string;
            *string-- = c;
        }
 
        return ( start );
}

Referenced by _mbsrev().