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#define INCL_DOSDEVICES
 
USHORT DosPhysicalDisk(usFunction, pbOutBuf, cbOutBuf, pbParmBuf,
    cbParmBuf)
USHORT usFunction;    /* action to take                       */
PBYTE pbOutBuf;       /* pointer to output buffer             */
USHORT cbOutBuf;      /* output-buffer length                 */
PBYTE pbParmBuf;      /* pointer to user-supplied information */
USHORT cbParmBuf;     /* length of user-supplied information  */
 
The DosPhysicalDisk function retrieves information about partitionable
disks.
 
Parameter   Description
────────────────────────────────────────────────────────────────────────────
 
usFunction  Specifies the action to take. It can be one of the following
            values:
 
            Value                           Meaning
            ────────────────────────────────────────────────────────────────
            INFO_COUNT_PARTITIONABLE_DISKS  Retrieve the total number of
                                            partitionable disks.
 
            INFO_FREEIOCTLHANDLE            Release the handle obtained by a
                                            previous call to
                                            DosPhysicalDisk.
 
            INFO_GETIOCTLHANDLE             Retrieve a handle to use with
                                            Category 9 IOCtl functions
                                            (Category 9 IOCtl functions have
                                            the prefix PDSK_).
 
pbOutBuf    Points to the buffer that receives output information.
 
cbOutBuf    Specifies the length (in bytes) of the output buffer.
 
pbParmBuf   Points to a buffer that contains parameter data.
 
cbParmBuf   Specifies the length (in bytes) of the parameter buffer.
 
Return Value
 
The return value is zero if the function is successful. Otherwise, it is an
error value.
 
Comments
 
When DosPhysicalDisk is used to obtain a handle to a partitionable physical
drive (a usFunction value of INFO_GETIOCTLHANDLE), the pbParmBuf parameter
should point to a null-terminated string that contains the drive number and
a colon (:). The cbParmBuf parameter must contain the length of the entire
string, including the trailing null character. For example, to obtain a
handle for the first partitionable disk, pbParmBuf should point to "1:" and
cbParmBuf should be 3.
 
The organization and content of the output buffer depend on the given
function, as follows:
 
Function                          cbOutBuf    pbOutBuf
────────────────────────────────────────────────────────────────────────────
INFO_COUNT_PARTITIONABLE_DISKS    2           Total number of partitionable
                                              disks in the system
                                              (one-based).
 
INFO_FREEIOCTLHANDLE              2           Handle for the specified
                                              partitionable disk for the
                                              Category 9 IOCtl functions.
 
INFO_GETIOCTLHANDLE               0           None. Pointer must be NULL.
 
The organization and content of the parameter buffer depend on the given
function, as follows:
 
Function                          cbParmBuf        pbParmBuf
────────────────────────────────────────────────────────────────────────────
INFO_COUNT_PARTITIONABLE_DISKS    0                None. Must be NULL.
 
INFO_FREEIOCTLHANDLE              String length    Null-terminated string
                                                   that specifies the
                                                   partitionable disk. The
                                                   string consists of a
                                                   number that specifies the
                                                   disk, immediately
                                                   followed by a colon.
                                                   Partitionable disk
                                                   numbers start at 1.
 
INFO_GETIOCTLHANDLE               2                Handle retrieved by the
                                                   INFO_FREEIOCTLHANDLE
                                                   function.
 
Example
 
This example calls the DosPhysicalDisk function to determine the total
number of partitionable disks. The total value is placed in the
usDataBuffer variable.
 
USHORT usDataBuffer;
 
DosPhysicalDisk(INFO_COUNT_PARTITIONABLE_DISKS,
    (PBYTE) &usDataBuffer,      /* address of data buffer    */
    sizeof(USHORT),             /* length of data buffer     */
    (PBYTE) NULL,               /* pointer to parameter list */
    0);                         /* length of parameter list  */
 
See Also
 
DosDevConfig, DosDevIOCtl
 
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