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Inside Macintosh: Files /
Chapter 2 - File Manager / File Manager Reference
Data Structures

Volume Attributes Buffer

The low-level HFS function PBHGetVolParms returns information in the volume attributes buffer, defined by the GetVolParmsInfoBuffer data type.

TYPE GetVolParmsInfoBuffer =
RECORD
   vMVersion:        Integer;    {version number}
   vMAttrib:         LongInt;    {volume attributes}
   vMLocalHand:      Handle;     {reserved}
   vMServerAdr:      LongInt;    {network server address}
   vMVolumeGrade:    LongInt;    {relative speed rating}
   vMForeignPrivID:  Integer;    {foreign privilege model}
END;
Field Description
vMVersion
The version of the attributes buffer structure. Currently this field returns either 1 or 2.
vMAttrib
A 32-bit quantity that encodes information about the volume attributes. See the list of constants in the description of PBHGetVolParms beginning on page 2-147 for details on the meaning of each bit.
vMLocalHand
A handle to private data for shared volumes. On creation of the VCB (right after mounting), this field is a handle to a 2-byte block
of memory. The Finder uses this for its local window list storage, allocating and deallocating memory as needed. It is disposed of when the volume is unmounted. Your application should treat this field as reserved.
vMServerAdr
For AppleTalk server volumes, this field contains the internet address of an AppleTalk server volume. Your application can inspect this field to tell which volumes belong to which server; the value of this field is 0 if the volume does not have a server.
vMVolumeGrade
The relative speed rating of the volume. The scale used to determine these values is currently uncalibrated. In general,
lower values indicate faster speeds. A value of 0 indicates that
the volume's speed is unrated. The buffer version returned in
the vMVersion field must be greater than 1 for this field to
be meaningful.
vMForeignPrivID

An integer representing the privilege model supported by the volume. Currently two values are defined for this field:
0 represents a standard HFS volume that might or might not support the AFP privilege model; fsUnixPriv represents a volume that supports the A/UX privilege model. The buffer
version returned in the vMVersion field must be greater than 1
for this field to be meaningful.
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© Apple Computer, Inc.
2 JUL 1996