Alterando a configuração de um serviço

  • Artigo

Um programa de configuração de serviço usa as funções ChangeServiceConfig e ChangeServiceConfig2 para alterar os parâmetros de configuração de um serviço instalado. O programa abre um identificador para o objeto de serviço, modifica sua configuração e fecha o identificador do objeto de serviço.

No exemplo a seguir, a função DoDisableSvc usa ChangeServiceConfig para alterar o tipo de início do serviço para "Desabilitado", a função DoEnableSvc usa ChangeServiceConfig para alterar o tipo de início do serviço para "Habilitado", e a função DoUpdateSvcDesc usa ChangeServiceConfig2 para definir a descrição do serviço como "Esta é uma descrição de teste". A variável szSvcName é uma variável global que contém o nome do serviço. Para obter o exemplo completo que define essa variável, consulte SvcConfig.cpp.

//
// Purpose: 
//   Disables the service.
//
// Parameters:
//   None
// 
// Return value:
//   None
//
VOID __stdcall DoDisableSvc()
{
    SC_HANDLE schSCManager;
    SC_HANDLE schService;

    // Get a handle to the SCM database. 
 
    schSCManager = OpenSCManager( 
        NULL,                    // local computer
        NULL,                    // ServicesActive database 
        SC_MANAGER_ALL_ACCESS);  // full access rights 
 
    if (NULL == schSCManager) 
    {
        printf("OpenSCManager failed (%d)\n", GetLastError());
        return;
    }

    // Get a handle to the service.

    schService = OpenService( 
        schSCManager,            // SCM database 
        szSvcName,               // name of service 
        SERVICE_CHANGE_CONFIG);  // need change config access 
 
    if (schService == NULL)
    { 
        printf("OpenService failed (%d)\n", GetLastError()); 
        CloseServiceHandle(schSCManager);
        return;
    }    

    // Change the service start type.

    if (! ChangeServiceConfig( 
        schService,        // handle of service 
        SERVICE_NO_CHANGE, // service type: no change 
        SERVICE_DISABLED,  // service start type 
        SERVICE_NO_CHANGE, // error control: no change 
        NULL,              // binary path: no change 
        NULL,              // load order group: no change 
        NULL,              // tag ID: no change 
        NULL,              // dependencies: no change 
        NULL,              // account name: no change 
        NULL,              // password: no change 
        NULL) )            // display name: no change
    {
        printf("ChangeServiceConfig failed (%d)\n", GetLastError()); 
    }
    else printf("Service disabled successfully.\n"); 

    CloseServiceHandle(schService); 
    CloseServiceHandle(schSCManager);
}

//
// Purpose: 
//   Enables the service.
//
// Parameters:
//   None
// 
// Return value:
//   None
//
VOID __stdcall DoEnableSvc()
{
    SC_HANDLE schSCManager;
    SC_HANDLE schService;

    // Get a handle to the SCM database. 
 
    schSCManager = OpenSCManager( 
        NULL,                    // local computer
        NULL,                    // ServicesActive database 
        SC_MANAGER_ALL_ACCESS);  // full access rights 
 
    if (NULL == schSCManager) 
    {
        printf("OpenSCManager failed (%d)\n", GetLastError());
        return;
    }

    // Get a handle to the service.

    schService = OpenService( 
        schSCManager,            // SCM database 
        szSvcName,               // name of service 
        SERVICE_CHANGE_CONFIG);  // need change config access 
 
    if (schService == NULL)
    { 
        printf("OpenService failed (%d)\n", GetLastError()); 
        CloseServiceHandle(schSCManager);
        return;
    }    

    // Change the service start type.

    if (! ChangeServiceConfig( 
        schService,            // handle of service 
        SERVICE_NO_CHANGE,     // service type: no change 
        SERVICE_DEMAND_START,  // service start type 
        SERVICE_NO_CHANGE,     // error control: no change 
        NULL,                  // binary path: no change 
        NULL,                  // load order group: no change 
        NULL,                  // tag ID: no change 
        NULL,                  // dependencies: no change 
        NULL,                  // account name: no change 
        NULL,                  // password: no change 
        NULL) )                // display name: no change
    {
        printf("ChangeServiceConfig failed (%d)\n", GetLastError()); 
    }
    else printf("Service enabled successfully.\n"); 

    CloseServiceHandle(schService); 
    CloseServiceHandle(schSCManager);
}

//
// Purpose: 
//   Updates the service description to "This is a test description".
//
// Parameters:
//   None
// 
// Return value:
//   None
//
VOID __stdcall DoUpdateSvcDesc()
{
    SC_HANDLE schSCManager;
    SC_HANDLE schService;
    SERVICE_DESCRIPTION sd;
    LPTSTR szDesc = TEXT("This is a test description");

    // Get a handle to the SCM database. 
 
    schSCManager = OpenSCManager( 
        NULL,                    // local computer
        NULL,                    // ServicesActive database 
        SC_MANAGER_ALL_ACCESS);  // full access rights 
 
    if (NULL == schSCManager) 
    {
        printf("OpenSCManager failed (%d)\n", GetLastError());
        return;
    }

    // Get a handle to the service.

    schService = OpenService( 
        schSCManager,            // SCM database 
        szSvcName,               // name of service 
        SERVICE_CHANGE_CONFIG);  // need change config access 
 
    if (schService == NULL)
    { 
        printf("OpenService failed (%d)\n", GetLastError()); 
        CloseServiceHandle(schSCManager);
        return;
    }    

    // Change the service description.

    sd.lpDescription = szDesc;

    if( !ChangeServiceConfig2(
        schService,                 // handle to service
        SERVICE_CONFIG_DESCRIPTION, // change: description
        &sd) )                      // new description
    {
        printf("ChangeServiceConfig2 failed\n");
    }
    else printf("Service description updated successfully.\n");

    CloseServiceHandle(schService); 
    CloseServiceHandle(schSCManager);
}

Configuração de serviço

O exemplo de serviço completo