getprinterdata

#include "stdafx.h"
#include "windows.h"
#include <thread>
#include <iostream>

#pragma comment(lib, "Winspool.lib")

typedef struct _CStatusThreadInfo
{
  DWORD dSleepTime;
  HANDLE hPrinter;
  HANDLE hError;
  HANDLE hStatus;
} CStatusThreadInfo;

void monitorZebraPrinter(CStatusThreadInfo *pInfo) {

  HANDLE handles[2] = {
    pInfo->hError,
    pInfo->hStatus
  };

  DWORD dType = 0;
  DWORD dRet = 0;
  DWORD dNeeded = 0;
  DWORD dwResult = 0;

  printf("entering listening thread...\n");

  while (true) {
    printf("waiting for one or multiple events to be signaled by LM\n");
    printf("--------------------------------------------------------");
    dRet = WaitForMultipleObjects(2, handles, FALSE, pInfo->dSleepTime);
    if (dRet != WAIT_FAILED) {
      if (dRet == WAIT_OBJECT_0 || dRet == WAIT_OBJECT_0 + 1) {
        GetPrinterData(pInfo->hPrinter, L"Error", &dType, (LPBYTE) &dwResult, sizeof(dwResult), &dNeeded);
        printf("Error (WINDOWS): 0x%08X\n", dwResult);
        GetPrinterData(pInfo->hPrinter, L"ExternalError", &dType, (LPBYTE) &dwResult, sizeof(dwResult), &dNeeded);
        printf("ExternalError (Zebra specific): 0x%08X\n", dwResult);
      }
    }
  }

};

static std::wstring GetEventName(HANDLE hPrinter, LPWSTR eventName) {
  BYTE tmp[100];
  DWORD dType = 0;
  DWORD dRet = 0;
  DWORD dNeeded = 0;
  if (dRet = GetPrinterData(hPrinter, eventName, &dType, (LPBYTE) tmp, 100, &dNeeded) != ERROR_SUCCESS){
    return NULL;
  }
  return std::wstring((wchar_t*) tmp);
};

int _tmain(int argc, _TCHAR* argv []){

  HANDLE hPrinter = NULL;
  LPWSTR printerName = _T("Zebra TTP 2030 (Copy 1)");

  BOOL bStatus = OpenPrinter(printerName, &hPrinter, NULL);
  if (!bStatus) {
    printf("failed to open printer");
    return -1;
  }

  std::wstring statusEvent = GetEventName(hPrinter, L"StatusEvent");
  if (statusEvent.empty()) {
    printf("failed to get status event name");
    return -1;
  }

  std::wstring errorEvent = GetEventName(hPrinter, L"ErrorEvent");
  if (errorEvent.empty()) {
    printf("failed to get error event name");
    return -1;
  }

  wprintf(L"statusEvent: %s\n", statusEvent.c_str());
  wprintf(L"errorEvent: %s\n", errorEvent.c_str());

  CStatusThreadInfo cti;

  cti.hPrinter = hPrinter;
  cti.dSleepTime = INFINITE;
  cti.hStatus = OpenEvent(SYNCHRONIZE, TRUE, statusEvent.c_str()); // USB002StatusEvent
  cti.hError = OpenEvent(SYNCHRONIZE, TRUE, errorEvent.c_str()); // USB002ErrorEvent

  if (cti.hStatus == NULL) {
    wprintf(L"failed to open event %s. reason: %d", statusEvent.c_str(), GetLastError());
    return -1;
  }

  if (cti.hError == NULL) {
    wprintf(L"failed to open event %s. reason: %d", errorEvent.c_str(), GetLastError());
    return -1;
  }

  printf("ready...\n");

  std::thread poll(monitorZebraPrinter, &cti);
  poll.join();

  return 0;
};