Performs control functions on a device specified by an opened device handle.
#define INCL_DOSDEVICES
#define INCL_DOSDEVIOCTL
#include <os2.h>
HFILE hDevice; /* Device handle returned by DosOpen, or a standard (open) device handle. */
ULONG category; /* Device category. */
ULONG function; /* Device-specific function code. */
PVOID pParams; /* Address of the command-specific argument list. */
ULONG cbParmLenMax; /* Length, in bytes, of pParams. */
PULONG pcbParmLen; /* Pointer to the length of parameters. */
PVOID pData; /* Address of the data area. */
ULONG cbDataLenMax; /* Length, in bytes, of pData. */
PULONG pcbDataLen; /* Pointer to the length of data. */
APIRET ulrc; /* Return Code. */
ulrc = DosDevIOCtl(hDevice, category, function,
pParams, cbParmLenMax, pcbParmLen,
pData, cbDataLenMax, pcbDataLen);