DosPhysicalDisk (FAPI)

This call obtains information about partitionable disks.

This is the legacy function, please visit DosPhysicalDisk for the current version.

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