Determine if my program is running in the active season, CPP on Windows?

It’s Not Quite Easy to Determine If Your C or C++ Program is Running in the Active Session, But It’s Not Impossible! Here’s the Solution!

1. Is My C++ or C Program Running in the Active Session on Windows?
2. Why Is It Useful to Know If the Program Is in the Active Session?
3. What to Watch Out For When Checking If the Program Is Running in the Active Session?

1.) Is My C++ or C Program Running in the Active Session on Windows?

#include <iostream>
#include <windows.h>
#include <wtsapi32.h>

// Function to check if the program is running in the active user session
int IsActiveSession()
{
  // Initialize Windows Terminal Services API
  if (WTSOpenServerW(NULL) == 0)
  {
      // Error handling: API initialization failed
      return 1;
  }

  // Session information and counter for sessions
  WTS_SESSION_INFO* sessionInfo = nullptr;
  DWORD sessionCount = 0;

  // Session ID of the current process and variable for activity check
  DWORD sessionId;
  bool isActive = false;

  // Get the current process ID
  DWORD processId = GetCurrentProcessId();

  // Convert process ID to session ID
  ProcessIdToSessionId(processId, &sessionId);

  // Enumerate sessions on the current server
  if (WTSEnumerateSessions(WTS_CURRENT_SERVER_HANDLE, 0, 1, &sessionInfo, &sessionCount))
  {
      for (DWORD i = 0; i < sessionCount; ++i)
      {
          // Output session ID and status
          wprintf(L"Session ID: %d\n", sessionInfo[i].SessionId);
          wprintf(L"Status: %d\n", sessionInfo[i].State);
        
          // Check if the session is active
          if (sessionInfo[i].State == WTSActive)
          {
              std::wcout << L"Active Session: " << sessionInfo[i].SessionId << std::endl;
            
              // Check if the current process is running in this active session
              if (sessionId == sessionInfo[i].SessionId)
              {
                  isActive = true;
                  std::wcout << L"The program is running in the active session: " << sessionId << std::endl;
              }
          }
        
          // Add an empty line for separation
          std::wcout << std::endl;
      }
    
      // Free allocated memory
      WTSFreeMemory(sessionInfo);
  }
  else
  {
      // Error handling: Enumeration of sessions failed
  }

  // Close Windows Terminal Services API
  WTSCloseServer(WTS_CURRENT_SERVER_HANDLE);

  // Return whether the program is running in the active session
  return isActive;
}

int main()
{
  // Call the function to check the active session and return the result
  return IsActiveSession();
}

2.) Why Is It Useful to Know If the Program Is in the Active Session?

3.) What to Watch Out For When Checking If the Program Is Running in the Active Session?