#define INCL_DOSDEVICES USHORT rc = DosDevIOCtl(Data, ParmList, Function, Category, DevHandle); PVOID Data; /* Data area */ PVOID ParmList; /* Command arguments */ USHORT Function; /* Device function */ USHORT Category; /* Device category */ HFILE DevHandle; /* Specifies the device */ USHORT rc; /* return code */