Platform SDK: DLLs, Processes, and Threads

EnumDependentServices

The EnumDependentServices function retrieves the name and status of each service that depends on the specified service; that is, the specified service must be running before the dependent services can run.

BOOL EnumDependentServices(
  SC_HANDLE hService,               // handle to service
  DWORD dwServiceState,             // service state
  LPENUM_SERVICE_STATUS lpServices, // status buffer
  DWORD cbBufSize,                  // size of status buffer
  LPDWORD pcbBytesNeeded,           // buffer size needed
  LPDWORD lpServicesReturned        // number of entries returned
);

Parameters

hService
[in] Handle to the service. This handle is returned by the OpenService or CreateService function, and it must have SERVICE_ENUMERATE_DEPENDENTS access.
dwServiceState
[in] Specifies the services to enumerate based on their state. This parameter must be one of the following values.
Value Meaning
SERVICE_ACTIVE Enumerates services that are in the following states: SERVICE_START_PENDING, SERVICE_STOP_PENDING, SERVICE_RUNNING, SERVICE_CONTINUE_PENDING, SERVICE_PAUSE_PENDING, and SERVICE_PAUSED.
SERVICE_INACTIVE Enumerates services that are in the SERVICE_STOPPED state.
SERVICE_STATE_ALL Combines the following states: SERVICE_ACTIVE and SERVICE_INACTIVE.

lpServices
[out] Pointer to an array of ENUM_SERVICE_STATUS structures that receives the name and service status information for each dependent service in the database. The buffer must be large enough to hold the structures, plus the strings to which their members point.

The order of the services in this array is the reverse of the start order of the services. In other words, the first service in the array is the one that would be started last, and the last service in the array is the one that would be started first.

cbBufSize
[in] Specifies the size, in bytes, of the buffer pointed to by the lpServices parameter.
pcbBytesNeeded
[out] Pointer to a variable that receives the number of bytes needed to store the array of service entries. The variable only receives this value if the buffer pointed to by lpServices is too small, indicated by function failure and the ERROR_MORE_DATA error; otherwise, the contents of pcbBytesNeeded are undefined.
lpServicesReturned
[out] Pointer to a variable that receives the number of service entries returned.

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.

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

Error code Meaning
ERROR_ACCESS_DENIED The specified handle was not opened with SERVICE_ENUMERATE_DEPENDENTS access.
ERROR_INVALID_HANDLE The specified handle is invalid.
ERROR_INVALID_PARAMETER A parameter that was specified is invalid.
ERROR_MORE_DATA The buffer pointed to by lpServices is not large enough. The function sets the variable pointed to by lpServicesReturned to the actual number of service entries stored into the buffer. The function sets the variable pointed to by pcbBytesNeeded to the number of bytes required to store all of the service entries.

Remarks

The returned services entries are ordered in the reverse order of the start order, with group order taken into account. If you need to stop the dependent services, you can use the order of entries written to the lpServices buffer to stop the dependent services in the proper order.

Requirements

  Windows NT/2000: Requires Windows NT 3.1 or later.
  Header: Declared in Winsvc.h; include Windows.h.
  Library: Use Advapi32.lib.
  Unicode: Implemented as Unicode and ANSI versions on Windows NT/2000.

See Also

Services Overview, Service Functions, CreateService, ENUM_SERVICE_STATUS, EnumServicesStatus, OpenService