C / C++ / MFC

#include <windows.h>
#include <malloc.h>
#include <string>
namespace std {
#ifdef _UNICODE
  typedef wstring tstring;
#else
  typedef string tstring;
#endif
};
std::tstring RunProcessAndCaptureOutput(LPCTSTR CmdLine, DWORD maxWaitTime = INFINITE)
{
  LPTSTR copyOfCmdLine = LPTSTR(alloca(sizeof(TCHAR) * (lstrlen(CmdLine) + 1)));
  lstrcpy(copyOfCmdLine, CmdLine);
  std::tstring s;
  SECURITY_ATTRIBUTES SecAttr;
  SecAttr.nLength = sizeof(SecAttr);
  SecAttr.lpSecurityDescriptor = NULL;
  SecAttr.bInheritHandle = TRUE;

  HANDLE hRead, hWrite;
  if (::CreatePipe(&hRead, &hWrite, &SecAttr, 0)) {
    STARTUPINFO StartupInfo;
    ZeroMemory(&StartupInfo, sizeof(StartupInfo));
    StartupInfo.cb = sizeof(StartupInfo);
    StartupInfo.dwFlags = STARTF_FORCEOFFFEEDBACK|STARTF_USESTDHANDLES;
    StartupInfo.hStdError = hWrite;
    StartupInfo.hStdOutput = hWrite;
    PROCESS_INFORMATION ProcessInfo;

    if (::CreateProcess(NULL, copyOfCmdLine, NULL, NULL, TRUE, DETACHED_PROCESS, NULL, NULL, &StartupInfo, &ProcessInfo)) {
      std::tstring capturedOutput;
      const DWORD smallWaitTime = 100;
      __int64 ftEnd;
      GetSystemTimeAsFileTime(LPFILETIME(&ftEnd));
      ftEnd += __int64(maxWaitTime) * __int64(10000);
      CloseHandle(hWrite);
      while (::WaitForSingleObject(ProcessInfo.hProcess, smallWaitTime) != WAIT_OBJECT_0) {
        EmptyPipeAndAppendToString(hRead, capturedOutput);
        __int64 ftNow;
        GetSystemTimeAsFileTime(LPFILETIME(&ftNow));
        if (ftNow > ftEnd) {
          s += "Command \"";
          s += CmdLine;
          s += "\" timed out.";
          s += " Partial output received\r\n\r\n";
          break;
        }
      }
      EmptyPipeAndAppendToString(hRead, capturedOutput);
      CloseHandle(ProcessInfo.hProcess);
      CloseHandle(ProcessInfo.hThread);
      s += capturedOutput;
      s += "\r\n\r\n";
    }
    else {
      CloseHandle(hWrite);
      s += "Error creating process with command \"";
      s += CmdLine;
      s += "\"\r\n\r\n";
    }
    CloseHandle(hRead);
  }
  else {
    s += "Error creating pipe\r\n\r\n";
  }
  return s;
}