유니코드 UTF-8로 변환하는 방법 질문입니다.

int W2UTF8Convert( const wchar_t* a_szSrc, int a_nSrcSize, char* a_szDest, int a_nDestSize )  
{  
#ifdef WINDOWS  
	return WideCharToMultiByte( CP_UTF8, 0, a_szSrc, -1, a_szDest, a_nDestSize, NULL, NULL );  
#else  
	size_t result;  
	iconv_t env;  
 
        env = iconv_open("UTF-8","UTF-32");
       	env = iconv_open("UTF-8","WCHAR_T");
	if (env==(iconv_t)-1)  
	{  
		printf("iconv_open WCHAR_T->UTF8 error%s %d/n",strerror(errno),errno) ;  
		return -1;  
	}  
	result = iconv(env,(const char**)&a_szSrc,(size_t*)&a_nSrcSize,(char**)&a_szDest,(size_t*)&a_nDestSize);  
	if (result==(size_t)-1)  
	{  
		printf("iconv WCHAR_T->UTF8 error %d/n",errno) ;
		return -1;  
	}  
	iconv_close(env);  
	return (int)result;  
#endif  
}