GetFinalPathNameByHandle Behaviour, C++ (vc++)

GetFinalPathNameByHandle Behaviour

//Microsoft (R) C/C++ Optimizing Compiler Version 19.00.23506 for x64

#include <windows.h>
#include <iostream>
#include <sstream>
#include <memory>
#include <tchar.h>
#include <io.h>
#include <string>

std::string GetLastErrorStdStr()
{
  DWORD error = GetLastError();
  if (error)
  {
    LPVOID lpMsgBuf;
    DWORD bufLen = FormatMessage(
        FORMAT_MESSAGE_ALLOCATE_BUFFER | 
        FORMAT_MESSAGE_FROM_SYSTEM |
        FORMAT_MESSAGE_IGNORE_INSERTS,
        NULL,
        error,
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
        (LPTSTR) &lpMsgBuf,
        0, NULL );
    if (bufLen)
    {
      LPCSTR lpMsgStr = (LPCSTR)lpMsgBuf;
      std::string result(lpMsgStr, lpMsgStr+bufLen);
      std::ostringstream ostr;
      ostr << error << " "
          << result;
      
      LocalFree(lpMsgBuf);

return ostr.str();
    }
  }
  return std::string();
}

inline bool isMsysPty(int fd) noexcept
{
#if defined(UNICODE) || defined(_UNICODE)
    LPCSTR functionName = "GetFinalPathNameByHandleW";
#else
    LPCSTR functionName = "GetFinalPathNameByHandleA";
#endif
    const auto ptrGetFinalPathNameByHandle
        = reinterpret_cast<decltype(&GetFinalPathNameByHandle)>(
            GetProcAddress(GetModuleHandle(TEXT("kernel32.dll")),
                functionName));
    if (!ptrGetFinalPathNameByHandle) {
        return false;
    }

using STDTString = std::basic_string<TCHAR>;
    HANDLE h = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
    if (h == INVALID_HANDLE_VALUE) {
        return false;
    }
    if (GetFileType(h) != FILE_TYPE_PIPE) {
        return false;
    }
    TCHAR Path[MAX_PATH] = { _T('\0') };
    const DWORD retSize = ptrGetFinalPathNameByHandle(h, Path, MAX_PATH, VOLUME_NAME_NONE | FILE_NAME_OPENED);
    if (!retSize || retSize >= MAX_PATH) {

// DEBUG OUTPUT:
        std::cout << "ERROR GetFinalPathNameByHandle: " << GetLastErrorStdStr() << std::endl;
        // Next try to use GetFinalPathNameByHandleEx:
        
        const size_t sizeNameInfo = sizeof(FILE_NAME_INFO) + sizeof(WCHAR) * MAX_PATH;

auto pNameInfo = std::unique_ptr<FILE_NAME_INFO, decltype(&std::free)>(
            static_cast<FILE_NAME_INFO*>(std::malloc(sizeNameInfo)), &std::free);
        
        // But GetFileInformationByHandleEx returns no error
        if(GetFileInformationByHandleEx(h, FileNameInfo, pNameInfo.get(), sizeNameInfo)) {
            std::wstring name(pNameInfo->FileName, pNameInfo->FileNameLength / sizeof(WCHAR));
            std::wcout << "GetFileInformationByHandleEx No errors, and path is: " << name << std::endl;
        }
        
    
        return false;
    }
    STDTString name(Path,retSize);
    if ((name.find(STDTString(TEXT("msys-"))) == STDTString::npos
        && name.find(STDTString(TEXT("cygwin-"))) == STDTString::npos)
        || name.find(STDTString(TEXT("-pty"))) == STDTString::npos) {
        return false;
    }
    // DEBUG OUTPUT:
#if defined(UNICODE) || defined(_UNICODE)
    std::wcout << name << std::endl;
#else
    std::cout << name << std::endl;
#endif
    return true;
}

int main()
{
    isMsysPty(0);
    isMsysPty(1);
    isMsysPty(2);
    std::wcout << L"Hello, world!\n";
}


run \| edit \| history \| help	0