DosPhysicalDisk (FAPI)

This call obtains information about partitionable disks.

Syntax

DosPhysicalDisk (Function, DataPtr, DataLen, ParmPtr, ParmLen)

Parameters

Function (USHORT) - input

The functions supported are:

1 - Obtain total number of partitionable disks

2 - Obtain a handle to use with Category 9 IOCTLs

3 - Release a handle for a partitionable disk.

DataPtr (PBYTE) - output

Address of the buffer where the returned information is placed.

DataLen (USHORT) - input

Length of the data buffer. The output data for each function is described below.

FUNCTION  DATALEN RETURNED INFORMATION
1         2       Total number of partitionable disks in the system, 1-based. 
2         2       Handle for the specified partitionable disk for the category 9 IOCTLs.
3         0       None. Pointer must be zero.

All lengths are in bytes.

ParmPtr (PBYTE) - input

Address of the buffer used for input parameters.

ParmLen (USHORT) - input

Length of the parameter buffer.

The input parameters required for each function are:

FUNCTION  PARMLEN  INPUT PARAMETERS
1         0        None.  Must be set to zero.
2         String length   ASCIIZ string that specifies the partitionable disk.
3         2               Handle obtained from function 2.

Note: All lengths are in bytes.

Return Code

rc (USHORT) - return

Return code descriptions are:

• 0 NO_ERROR
• ERROR_INVALID_FUNCTION
• ERROR_ACCESS_DENIED
• ERROR_INVALID_HANDLE
• 33 ERROR_LOCK_VIOLATION
• 87 ERROR_INVALID_PARAMETER

Remarks

The ASCIIZ string used to specify the partitionable disk must be of the following format:

number : <null byte>

Where:

number

specifies the partitionable disk (1-based) number in ASCII

:

must be present

<null byte>

the byte of 0 for the ASCIIZ string

The handle returned for the specified partitionable disk can only be used with the DosDevIOCtl call for the Category 9 Generic IOCTL. Use of the handle for a physical partitionable disk is not permitted for handle-based file system function calls, such as DosRead or DosClose.

Example Code

C Binding

#define INCL_DOSDEVICES

USHORT  rc = DosPhysicalDisk(Function, DataPtr, DataLen, ParmPtr, ParmLen);

USHORT           Function;      /* Type of information */
PBYTE            DataPtr;       /* Pointer to return buffer */
USHORT           DataLen;       /* Return buffer length */
PBYTE            ParmPtr;       /* Pointer to user-supplied information */
USHORT           ParmLen;       /* Length of user-supplied information */

USHORT           rc;            /* return code */

MASM Binding

EXTRN  DosPhysicalDisk:FAR
INCL_DOSDEVICES     EQU 1

PUSH   WORD    Function      ;Type of information
PUSH@  OTHER   DataPtr       ;Return buffer (returned)
PUSH   WORD    DataLen       ;Return buffer length
PUSH@  OTHER   ParmPtr       ;User-supplied information
PUSH   WORD    ParmLen       ;Length of user-supplied information
CALL   DosPhysicalDisk

Returns WORD