CM_Get_Device_ID_List_Size function

The CM_Get_Device_ID_List_Size function retrieves the buffer size required to hold a list of device instance IDs for the local machine's device instances.

Syntax

CMAPI
CONFIGRET
WINAPI CM_Get_Device_ID_List_Size(
  _Out_    PULONG pulLen,
  _In_opt_ PCTSTR pszFilter,
  _In_     ULONG  ulFlags
);

Parameters

pulLen [out]

Receives a value representing the required buffer size, in characters.

pszFilter [in, optional]

Caller-supplied pointer to a character string specifying a subset of the machine's device instance identifiers, or NULL. See the following description of ulFlags.

ulFlags [in]

One of the optional, caller-supplied bit flags that specify search filters. If no flags are specified, the function supplies the buffer size required to hold all instance identifiers for all device instances. For a list of bit flags, see the ulFlags description for CM_Get_Device_ID_List.

Return value

If the operation succeeds, the function returns CR_SUCCESS. Otherwise, it returns one of the CR_-prefixed error codes defined in Cfgmgr32.h.

Remarks

The CM_Get_Device_ID_List_Size function should be called to determine the buffer size required by CM_Get_Device_ID_List.

The size value supplied in the location pointed to by pulLen is guaranteed to represent a buffer size large enough to hold all device instance identifier strings and terminating NULLs. The supplied value might actually represent a buffer size that is larger than necessary, so don't assume the value represents the true length of the character strings that CM_Get_Device_ID_List will provide.

For information about device instance IDs, see Device Identification Strings.

Requirements

See also

CM_Get_Device_ID_List_Size_Ex

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