[SOLVED]create a child process with STDIN and STDOUT as being piped in UTF-16

Question

I have created a child process with the use of CreateProcessW function which has pipes to be as the STDOUT and STDIN between itself and its parent process. I am not able to use WriteFile and ReadFile functions to send and get back data as wide characters.

I am not aware of setting std::locale for pipes. Is there a way to specifically tell those pipes to encode data as wide characters in UTF-16, similar to what one uses for ifstreams and ofstreams?

Thanks.

Here you are:

static wchar_t buffer [sz];

int WriteToPipe(const std::wstring& str)
{
    int result = WriteFile(PipeStdin, (LPVOID)str.c_str(), str.size(), &bytesWritten, NULL);
    _assert(str.size()==bytesWritten);
    return  result;
}

// simply turns back what was on its stdin 
wchar_t* ReadFromPipe()
{
     ReadFile(PipeStdout, (LPVOID)buffer, sz, &bytesRead, NULL); 
     return buffer;
}   

void Test()
{
    std::wstring test  { L"test" };
    WriteToPipe (test);
    wchar_t* ret = ReadFromPipe (); // gets back 't' when using std::wcout
}

It gets only 't', apparently because the buffer was t \0 e \0 s \0 t \0.

If pipe's default encoding is UTF-8, it makes sense, otherwise I have to find out what is doing there. If I could set pipes to treat the buffer as UTF-16, then it would be good.

Answer 1

Solution:

I made two changes in my 'Preprocessor Defenitions' namely adding _UNICODE and _MBCS macros available and also adding UTF-16 mode for std::wcin as follows:

const unsigned long MaxCode = 0x10FFFF;
const std::codecvt_mode Mode = (std::codecvt_mode)(std::generate_header | std::little_endian);
std::locale utf16_locale(std::wcin.getloc(), new std::codecvt_utf16<wchar_t, MaxCode, Mode>);
std::wcin.imbue (utf16_locale);