bool utf8_to_utf16(const char *fpath)
{
bool ret = false;
HANDLE fileHandle;
DWORD fileSize;
PCHAR fileBuffer = nullptr;
char16_t* utf16Buffer = nullptr;
DWORD numberOfBytesRead;
DWORD numberOfBytesWritten;
fileHandle = ::CreateFileA(fpath,GENERIC_READ|GENERIC_WRITE,FILE_SHARE_READ,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL);
if (fileHandle == INVALID_HANDLE_VALUE)
return false;
do
{
fileSize = ::GetFileSize(fileHandle,NULL);
if (fileSize == 0)
break;
fileBuffer = new (std::nothrow) CHAR[fileSize];
if (fileBuffer == nullptr)
break;
if (::ReadFile(fileHandle,fileBuffer,fileSize,&numberOfBytesRead,NULL) == FALSE)
break;
int result = ::MultiByteToWideChar(
CP_UTF8, // Source string is in UTF-8
MB_PRECOMPOSED | MB_ERR_INVALID_CHARS, // Conversion flags
fileBuffer, // Source UTF-8 string pointer
fileSize, // Length of source UTF-8 string, in chars
NULL, // Pointer to destination buffer
0 // Size of destination buffer, in wchar_ts
);
if (result == 0)
break;
utf16Buffer = new (std::nothrow) char16_t[result];
if (utf16Buffer == nullptr)
break;
result = ::MultiByteToWideChar(
CP_UTF8, // Source string is in UTF-8
MB_PRECOMPOSED | MB_ERR_INVALID_CHARS, // Conversion flags
fileBuffer, // Source UTF-8 string pointer
fileSize, // Length of source UTF-8 string, in chars
(LPWSTR)utf16Buffer, // Pointer to destination buffer
result // Size of destination buffer, in wchar_ts
);
if (result == 0)
break;
if (::SetFilePointer(fileHandle,0,NULL,FILE_BEGIN) == FALSE)
break;
if (::WriteFile(fileHandle,"\xFF\xFE",2,&numberOfBytesWritten,NULL) == FALSE || numberOfBytesWritten !=2 )
break;
if (::WriteFile(fileHandle,utf16Buffer,result * sizeof(char16_t),&numberOfBytesWritten,NULL) == FALSE || numberOfBytesWritten != result * sizeof(char16_t))
break;
if (::SetEndOfFile(fileHandle) == FALSE)
break;
ret = true;
}while(0);
if (utf16Buffer)
delete utf16Buffer;
if (fileBuffer)
delete fileBuffer;
::CloseHandle(fileHandle);
return ret;
}
