- 1 year ago
How to find the com port number of a modem discovered using CM_Get_Device_Interface_List
To find the COM port number of a modem discovered using CM_Get_Device_Interface_List
, you can follow these steps in a C++ program using the Windows Driver Kit (WDK) and the Configuration Manager API:
Include the necessary headers:
cpp#include <windows.h>
#include <cfgmgr32.h>
Define the GUID for modem devices:
cppDEFINE_GUID(GUID_DEVINTERFACE_MODEM, 0x2C7089AA, 0x2E0E, 0x11D1, 0xB1, 0x2B, 0x00, 0xC0, 0x4F, 0xC2, 0xAA, 0xE2);
Call
CM_Get_Device_Interface_List
to retrieve the device interfaces:cppDWORD bufferSize = 0;
CONFIGRET cr = CM_Get_Device_Interface_List_Size(&bufferSize, const_cast<GUID*>(&GUID_DEVINTERFACE_MODEM), nullptr, CM_GET_DEVICE_INTERFACE_LIST_PRESENT);
if (cr == CR_SUCCESS) {
wchar_t* buffer = new wchar_t[bufferSize];
cr = CM_Get_Device_Interface_List(const_cast<GUID*>(&GUID_DEVINTERFACE_MODEM), nullptr, buffer, bufferSize, CM_GET_DEVICE_INTERFACE_LIST_PRESENT);
if (cr == CR_SUCCESS) {
// Process the device interfaces
// ...
delete[] buffer;
}
}
Iterate through the device interfaces to find the COM port:
cppwchar_t* deviceInterface = buffer;
while (*deviceInterface != '\0') {
// Get the COM port from the device interface
// ...
deviceInterface += wcslen(deviceInterface) + 1;
}
Retrieve the COM port number from the device interface:
cppwchar_t* comPortStart = wcsstr(deviceInterface, L"COM");
if (comPortStart != nullptr) {
int comPortNumber = _wtoi(comPortStart + 3); // Extract the COM port number
// Use the comPortNumber as needed
}
Remember to handle errors and release any allocated resources appropriately.
Please note that the above code is a simplified example, and additional error checking and handling may be required in a production-ready application. Additionally, you may need to adjust the code based on your specific requirements or programming environment.