PRINTER_INFO_6 not available using WIn32 api

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:

1. 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.
2. There is only PRINTER_INFO_6 defined but no _PRINTER_INFO_6W (Unicode) and _PRINTER_INFO_6A (ANSI) mentioned in the document.