WIn32API セッション情報を列挙する

セッション情報（ウィンドウステーション、セッションID、状態）を列挙するには、ターミナルサービスAPIのWTSEnumerateSessions関数を用いる。

BOOL WTSEnumerateSessions(
  HANDLE hServer, //ターミナルサーバーのハンドル(WSTOpenSeverで取得する)
  DWORD Reserved, //必ず0を指定する
  DWORD Version, //必ず1を指定する
  PWTS_SESSION_INFO *ppSessionInfo, //WTS_SESSION_INFO構造体配列へのポインタ
  DWORD *pCount //取得できたWTS_PROCESS構造体配列の要素数
);

WTS_SESSION_INFO構造体は、WtsApi32.h に以下のように定義されている。

typedef struct _WTS_SESSION_INFO {
  DWORD                  SessionId; //セッションID
  LPTSTR                 pWinStationName; //ウィンドウステーション名
  WTS_CONNECTSTATE_CLASS State; //セッション接続状態
} WTS_SESSION_INFO, *PWTS_SESSION_INFO;

WTS_CONNECTSTATE_CLASS列挙体は以下のように定義されている。

/*===================================================================
==   WTS_CONNECTSTATE_CLASS - Session connect state
=====================================================================*/

typedef enum _WTS_CONNECTSTATE_CLASS {
    WTSActive,              // User logged on to WinStation
    WTSConnected,           // WinStation connected to client
    WTSConnectQuery,        // In the process of connecting to client
    WTSShadow,              // Shadowing another WinStation
    WTSDisconnected,        // WinStation logged on without client
    WTSIdle,                // Waiting for client to connect
    WTSListen,              // WinStation is listening for connection
    WTSReset,               // WinStation is being reset
    WTSDown,                // WinStation is down due to error
    WTSInit,                // WinStation in initialization
} WTS_CONNECTSTATE_CLASS;

WTSEnumerateSessions関数で、このプログラムを実行中のターミナルサーバー上のウィンドウステーション名、セッションID、セッション接続状態を列挙するサンプルプログラム

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

#pragma comment(lib, "wtsapi32.lib")

const TCHAR * ToStringSessionConnectState(DWORD dwState)
{
    switch (dwState) {

    case WTSActive://User logged on to WinStation
        return TEXT("WTSActive");

    case WTSConnected://WinStation connected to client
        return TEXT("WTSConnected");
    
    case WTSConnectQuery://In the process of connecting to client
        return TEXT("WTSConnectQuery");
    
    case WTSShadow://Shadowing another WinStation
        return TEXT("WTSShadow");

    case WTSDisconnected://WinStation logged on without client
        return TEXT("WTSDisconnected");
    
    case WTSIdle://Waiting for client to connect
        return TEXT("WTSIdle");

    case WTSListen://WinStation is listening for connection
        return TEXT("WTSListen");

    case WTSReset://WinStation is being reset
        return TEXT("WTSReset");

    case WTSDown://WinStation is down due to error
        return TEXT("WTSDown");

    case WTSInit://WinStation in initialization
        return TEXT("WTSInit");
    
    default:
        return TEXT("Unknown");
 
    }
}

int main()
{
    PWTS_SESSION_INFO SessionInfo;
    DWORD dwCount = 0;

    WTSEnumerateSessions(WTS_CURRENT_SERVER_HANDLE,
        0,
        1,
        &SessionInfo,
        &dwCount);

    for (DWORD i=0; i < dwCount; i++) {
        _tprintf(TEXT("WinStationName:%s, SessionId:%d, State:%s\n"), 
            SessionInfo[i].pWinStationName, 
            SessionInfo[i].SessionId, 
            ToStringSessionConnectState(SessionInfo[i].State));
    }

    WTSFreeMemory(SessionInfo);

    return 0;
}

実行結果

WinStationName:Services, SessionId:0, State:WTSDisconnected
WinStationName:Console, SessionId:1, State:WTSActive

リモートPCのターミナルサーバーのセッション情報を取得するためには、WTSOpenServer関数でターミナルサーバーのハンドルをオープンする必要がある

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

#pragma comment(lib, "wtsapi32.lib")

const TCHAR * ToStringSessionConnectState(DWORD dwState)
{
    switch (dwState) {

    case WTSActive://User logged on to WinStation
        return TEXT("WTSActive");

    case WTSConnected://WinStation connected to client
        return TEXT("WTSConnected");
    
    case WTSConnectQuery://In the process of connecting to client
        return TEXT("WTSConnectQuery");
    
    case WTSShadow://Shadowing another WinStation
        return TEXT("WTSShadow");

    case WTSDisconnected://WinStation logged on without client
        return TEXT("WTSDisconnected");
    
    case WTSIdle://Waiting for client to connect
        return TEXT("WTSIdle");

    case WTSListen://WinStation is listening for connection
        return TEXT("WTSListen");

    case WTSReset://WinStation is being reset
        return TEXT("WTSReset");

    case WTSDown://WinStation is down due to error
        return TEXT("WTSDown");

    case WTSInit://WinStation in initialization
        return TEXT("WTSInit");
    
    default:
        return TEXT("Unknown");
 
    }
}

int main()
{
    HANDLE hServer;
    PWTS_SESSION_INFO SessionInfo;
    DWORD dwCount = 0;
    TCHAR szNetBiosName[] = TEXT(<span class="deco" style="color:#FF0000;">"リモートPCのNETBIOS名"</span>);//リモートPCのNETBIOS名を指定する

    hServer = WTSOpenServer(szNetBiosName);
    if (hServer == NULL) {
        return 1;
    }

    WTSEnumerateSessions(hServer,
        0,
        1,
        &SessionInfo,
        &dwCount);

    for (DWORD i=0; i < dwCount; i++) {
        _tprintf(TEXT("WinStationName:%s, SessionId:%d, State:%s\n"), 
            SessionInfo[i].pWinStationName, 
            SessionInfo[i].SessionId, 
            ToStringSessionConnectState(SessionInfo[i].State));
    }

    WTSFreeMemory(SessionInfo);
    WTSCloseServer(hServer);

    return 0;
}

参考

http://msdn.microsoft.com/ja-jp/library/cc429613.aspx