PRINTER_INFO_6 not available using WIn32 api - winapi

Question

I have been trying to get printer status from a DNP rx1 printer, but the status of the printer does not change when I open the tray of the printer. Here is an example using py32win library to access the status and it always return status = 0 event when the tray is open.
device_name = win32print.GetDefaultPrinter()
handle = win32print.OpenPrinter(device_name)
# Get the default properties for the printer
properties = win32print.GetPrinter(handle, 2)
When I try win32print.GetPrinter(handle, 6) # 6 = print_info_6 I get the some NotImplementedException. So my guess is that the firmware of the printer have not implemented print_info_6. So I can't get the status from the printer
I have also tried using powershell with:
Get-Printer | Select Name, PrinterStatus
Also no change in status when I open the tray or if there is a paper jam.
Is there anything that I'm overlooking? Is there anything else I can try to get the status of the printer?

Answer 1

PRINTER_INFO_6 works for me in C++ on Windows 10 1903 with OneNote printer.
And when I pause the printer I get status 0x00000001 (PRINTER_STATUS_PAUSED).
The C++ code I used for testing.
#pragma comment(lib, "Winspool")
int main()
{
DWORD bufSize;
WCHAR* buf = NULL;
HANDLE hPrinter = NULL;
PRINTER_INFO_6 info = {};
DWORD needed;
BOOL result = FALSE;
DWORD err;
// Get required buffer size
result = GetDefaultPrinter(NULL, &bufSize);
if(!result)
{
err = GetLastError();
if (ERROR_INSUFFICIENT_BUFFER != err)
{
std::cout << "GetDefaultPrinter failed with error: \n" << GetLastError();
return 0;
}
}
buf = (WCHAR*)calloc(bufSize, sizeof(WCHAR));
result = GetDefaultPrinter(buf, &bufSize);
if (!result)
{
std::cout << "GetDefaultPrinter failed with error: \n" << GetLastError();
return 0;
}
std::wcout << "Printer name: " << buf << "\n";
result = OpenPrinter(buf, &hPrinter, NULL);
if (!result)
{
std::cout << "OpenPrinter failed with error: \n" << GetLastError();
return 0;
}
result = GetPrinter(hPrinter, 6, (LPBYTE)&info, sizeof(PRINTER_INFO_6), &needed);
if (!result)
{
err = GetLastError();
if (ERROR_INSUFFICIENT_BUFFER != err)
{
std::cout << "GetPrinter failed with error: \n" << GetLastError();
return 0;
}
}
BYTE* statBuf = (BYTE*)calloc(needed, sizeof(BYTE));
result = GetPrinter(hPrinter, 6, statBuf, needed, &needed);
if (!result)
{
std::cout << "GetPrinter failed with error: \n" << GetLastError();
return 0;
}
std::cout << "Printer status (low 32bit): " << *((DWORD*)statBuf) << "\n";
statBuf += sizeof(DWORD);
std::cout << "Printer status (high 32bit): " << *((DWORD*)statBuf) << "\n";
getchar();
}
Some issues I found in testing:
Pinter status defined as a DWORD (4 bytes) in PRINTER_INFO_6 structure but GetPrinter requries 8 bytes for it (needed == 8). So you will get ERROR_INSUFFICIENT_BUFFER error when you pass a PRINTER_INFO_6 structure as pPrinter parameter.
There is only PRINTER_INFO_6 defined but no _PRINTER_INFO_6W (Unicode) and _PRINTER_INFO_6A (ANSI) mentioned in the document.