EnumServicesStatusA function (winsvc.h)

Article
02/09/2023

Enumerates services in the specified service control manager database. The name and status of each service are provided.

This function has been superseded by the EnumServicesStatusEx function. It returns the same information EnumServicesStatus returns, plus the process identifier and additional information for the service. In addition, EnumServicesStatusEx enables you to enumerate services that belong to a specified group.

Syntax

BOOL EnumServicesStatusA(
  [in]                SC_HANDLE              hSCManager,
  [in]                DWORD                  dwServiceType,
  [in]                DWORD                  dwServiceState,
  [out, optional]     LPENUM_SERVICE_STATUSA lpServices,
  [in]                DWORD                  cbBufSize,
  [out]               LPDWORD                pcbBytesNeeded,
  [out]               LPDWORD                lpServicesReturned,
  [in, out, optional] LPDWORD                lpResumeHandle
);

Parameters

[in] hSCManager

A handle to the service control manager database. This handle is returned by the OpenSCManager function, and must have the SC_MANAGER_ENUMERATE_SERVICE access right. For more information, see Service Security and Access Rights.

[in] dwServiceType

The type of services to be enumerated. This parameter can be one or more of the following values.

Value	Meaning
SERVICE_DRIVER 0x0000000B	Services of type SERVICE_KERNEL_DRIVER and SERVICE_FILE_SYSTEM_DRIVER.
SERVICE_FILE_SYSTEM_DRIVER 0x00000002	File system driver services.
SERVICE_KERNEL_DRIVER 0x00000001	Driver services.
SERVICE_WIN32 0x00000030	Services of type SERVICE_WIN32_OWN_PROCESS and SERVICE_WIN32_SHARE_PROCESS.
SERVICE_WIN32_OWN_PROCESS 0x00000010	Services that run in their own processes.
SERVICE_WIN32_SHARE_PROCESS 0x00000020	Services that share a process with one or more other services. For more information, see Service Programs.

[in] dwServiceState

The state of the services to be enumerated. This parameter can be one of the following values.

Value	Meaning
SERVICE_ACTIVE 0x00000001	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 0x00000002	Enumerates services that are in the SERVICE_STOPPED state.
SERVICE_STATE_ALL 0x00000003	Combines the following states: SERVICE_ACTIVE and SERVICE_INACTIVE.

[out, optional] lpServices

A pointer to a buffer that contains an array of ENUM_SERVICE_STATUS structures that receive the name and service status information for each service in the database. The buffer must be large enough to hold the structures, plus the strings to which their members point.

The maximum size of this array is 256K bytes. To determine the required size, specify NULL for this parameter and 0 for the cbBufSize parameter. The function will fail and GetLastError will return ERROR_INSUFFICIENT_BUFFER. The pcbBytesNeeded parameter will receive the required size.

Windows Server 2003 and Windows XP: The maximum size of this array is 64K bytes. This limit was increased as of Windows Server 2003 with SP1 and Windows XP with SP2.

[in] cbBufSize

The size of the buffer pointed to by the lpServices parameter, in bytes.

[out] pcbBytesNeeded

A pointer to a variable that receives the number of bytes needed to return the remaining service entries, if the buffer is too small.

[out] lpServicesReturned

A pointer to a variable that receives the number of service entries returned.

[in, out, optional] lpResumeHandle

A pointer to a variable that, on input, specifies the starting point of enumeration. You must set this value to zero the first time this function is called. On output, this value is zero if the function succeeds. However, if the function returns zero and the GetLastError function returns ERROR_MORE_DATA, this value is used to indicate the next service entry to be read when the function is called to retrieve the additional data.

Return value

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 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.

Return code	Description
ERROR_ACCESS_DENIED	The handle does not have the SC_MANAGER_ENUMERATE_SERVICE access right.
ERROR_INVALID_HANDLE	The specified handle is invalid.
ERROR_INVALID_PARAMETER	A parameter that was specified is invalid.
ERROR_MORE_DATA	There are more service entries than would fit into the lpServices buffer. The actual number of service entries written to lpServices is returned in the lpServicesReturned parameter. The number of bytes required to get the remaining entries is returned in the pcbBytesNeeded parameter. The remaining services can be enumerated by additional calls to EnumServicesStatus with the lpResumeHandle parameter indicating the next service to read.

Remarks

Note

The winsvc.h header defines EnumServicesStatus as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	winsvc.h (include Windows.h)
Library	Advapi32.lib
DLL	Advapi32.dll