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Listing Event Collector Subscriptions

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You can retrieve a list of names of Event Collector subscriptions that are enabled on a local computer. Using the EcOpenSubscriptionEnum function, you can obtain a handle to a subscription enumerator. After the handle is created, the EcEnumNextSubscription function is used to list the subscriptions on the local computer.

Note

You can use the following code example to retrieve a list of subscriptions or you can type the following command at the command prompt:

wecutil es

 

The following C++ code example shows how to list the Event Collector subscriptions.

#include <windows.h>
#include <EvColl.h>
#include <vector>
#include <strsafe.h>

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

void __cdecl wmain()
{
    // Lists the Event Collector subscriptions that are available 
    // on the local computer.
    DWORD dwBufferSizeUsed, dwError = ERROR_SUCCESS;
    BOOL bRetVal = true;
    std::vector<WCHAR> buffer(MAX_PATH);
    EC_HANDLE hEnumerator;
    DWORD dwRetVal;

    // Create a handle to access the subscriptions.
    hEnumerator = EcOpenSubscriptionEnum(NULL);

    if (hEnumerator)
    {
        while (bRetVal)
        {
            // Get the next subscription.
            bRetVal = EcEnumNextSubscription(hEnumerator, 
                (DWORD) buffer.size(),
                (LPWSTR) &buffer[0],
                &dwBufferSizeUsed);
            dwError = GetLastError();

            // If the buffer is not large enough, resize it to accommodate the
            // subscription information.
            if (!bRetVal && ERROR_INSUFFICIENT_BUFFER == dwError)
            {
                dwError = ERROR_SUCCESS;
                buffer.resize(dwBufferSizeUsed);

                bRetVal = EcEnumNextSubscription(hEnumerator,
                    (DWORD) buffer.size(),
                    (LPWSTR) &buffer[0],
                    &dwBufferSizeUsed);
                dwError = GetLastError();
            }

            if (!bRetVal && ERROR_NO_MORE_ITEMS == dwError)
            {
                dwError = ERROR_SUCCESS;
                break;
            }

            if (bRetVal && ERROR_SUCCESS != dwError)
            {
                break;
            }
            
            // Output the subscription name.
            wprintf(L"%s\n", (LPCWSTR) &buffer[0]);    
        }
    }
    else
    {
        dwRetVal = GetLastError();
        LPVOID lpwszBuffer;

        FormatMessageW( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
            NULL,
            dwRetVal,
            0,
            (LPWSTR) &lpwszBuffer,
            0,
            NULL);

        if (!lpwszBuffer)
        {
            wprintf(L"Failed to FormatMessage.  Operation Error Code: %u. Error Code from FormatMessage: %u\n", dwRetVal, GetLastError());
            return;
        }

        wprintf(L"\nFailed to Perform Operation.\nError Code: %u\nError Message: %s\n", dwRetVal, lpwszBuffer);

        LocalFree(lpwszBuffer);
    }

    EcClose(hEnumerator);
}

Windows Event Collector Reference