ControlService info  Overview  Group

The ControlService function sends a control code to a Win32-based service.

BOOL ControlService(

Parameters

hService

Identifies the service. This handle is returned by the OpenService or CreateService function. The access required for this handle depends on the dwControl code requested.

dwControl

Specifies the requested control code. This value can be one of the standard control codes in the following table:

Value	Meaning
SERVICE_CONTROL_STOP	Requests the service to stop. The hService handle must have SERVICE_STOP access.
SERVICE_CONTROL_PAUSE	Requests the service to pause. The hService handle must have SERVICE_PAUSE_CONTINUE access.
SERVICE_CONTROL_ CONTINUE	Requests the paused service to resume. The hService handle must have SERVICE_PAUSE_CONTINUE access.
SERVICE_CONTROL_ INTERROGATE	Requests the service to update immediately its current status information to the service control manager. The hService handle must have SERVICE_INTERROGATE access.
SERVICE_CONTROL_ SHUTDOWN	The ControlService function fails if this control code is specified.

This value can also be a user-defined control code, as described in the following table:

Value	Meaning
Range 128 to 255.	The service defines the action associated with the control code. The hService handle must have SERVICE_USER_DEFINED_CONTROL access.

lpServiceStatus

Points to a SERVICE_STATUS structure to receive the latest service status information. The information returned reflects the most recent status that the service reported to the service control manager.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Errors

The following error codes can be set by the service control manager. Other error codes can be set by the registry functions that are called by the service control manager.

Remarks

The ControlService function asks the service control manager to send the requested control code to the service. The service control manager sends the code if the service accepts the control and if the service is in a state in which a control can be sent to it. You cannot stop and start a service unless the security descriptor allows you to. The default security descriptor allows LocalSystem, Administrators, and Power Users to stop and start services. To change the security descriptor of a service, use SetServiceObjectSecurity.

The QueryServiceStatus or function returns a SERVICE_STATUS structure whose dwCurrentState and dwControlsAccepted members indicate the current state and controls accepted by a running service. All running services accept the SERVICE_CONTROL_INTERROGATE control code by default. Each service specifies the other control codes that it accepts when it calls the SetServiceStatus function to report its status. A service should always accept these codes when it is running, no matter what it is doing.

The following table shows the action of the service control manager in each of the possible service states:

See Also

CreateService, OpenService, QueryServiceStatus, SetServiceObjectSecurity, SetServiceStatus, SERVICE_STATUS

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