Inside Macintosh: Files /

Chapter 2 - File Manager / File Manager Reference

Shared Environment Routines / Mounting Volumes

PBGetVolMountInfoSize

You use the PBGetVolMountInfoSize function to determine how much space to allocate for a volume mounting information record.

FUNCTION PBGetVolMountInfoSize (paramBlock: ParmBlkPtr): OSErr;

paramBlock

A pointer to a basic File Manager parameter block.

-->	ioCompletion	LongInt	A pointer to a completion routine.
<--	ioResult	OSErr	The function's result code.
-->	ioVRefNum	Integer	A volume specification.
-->	ioBuffer	LongInt	A pointer to storage for size.

DESCRIPTION

For a specified volume, the PBGetVolMountInfoSize function provides the size
of the record needed to hold the volume's mounting information. The ioBuffer
field is a pointer to the size information, which is of type Integer (2 bytes). If PBGetVolMountInfoSize returns noErr, that integer contains the size of the
volume mounting information record.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for PBGetVolMountInfoSize are

Trap macro	Selector
_HFSDispatch	$003F

RESULT CODES

noErr	0	No error
nsvErr	-35	Volume not found
paramErr	-50	Parameter error
extFSErr	-58	External file system error; typically, function is not available for that volume