PBGetVInfoSync
PBGetVInfo Get information about a volume
#include <Files.h> File Manager (PBxxx)
OSErr PBGetVInfo(pb, async ); Boolean async ; 0=await completion; 1=immediate return PBGetVInfo obtains information about a specified volume or directory,
including the volume attributes, creation and modification date/time, size of
allocation blocks, number of files in the root (or specified directory), etc.
pb is the address of a 64-byte VolumeParam structure. The following fields are relevant:
Out-In Name Type Size Offset Description
-> ioCompletion ProcPtr 4 12 Completion routine address (if async =TRUE) -> ioVolIndex short 2 28 (>0= index, <0=use name/num, 0=use num)
<-> ioNamePtr StringPtr 4 18 Address of full or partial path/ filename <-> ioVRefNum short 2 22 Volume, drive, or working directory reference
<- ioResult OSErr 2 16 Error Code (0=no error, 1=not done yet) <- ioVCrDate long 4 30 Date/time volume created
<- ioVLsBkUp long 4 34 Date/time volume information was modified
<- ioVAtrb short 2 38 volume attributes (bit 15=locked, etc.)
<- ioVNmFls short 2 40 Count of files in the (root) directory
<- ioVDirSt short 2 42 First allocation block of directory
<- ioVBlLn short 2 44 Length of directory in blocks
<- ioVNmAlBlks short 2 46 Count of all allocation blocks
<- ioVAlBlkSiz long 4 48 Allocation block size, in bytes
<- ioVClpSiz long 4 52 Default allocation clump, in bytes
<- ioAlBlSt short 2 56 First block in volume block map
<- ioVNxtFNum long 4 58 Next unused file number
<- ioVFrBlk short 2 62 Count of free allocation blocks
async is a Boolean value. Use FALSE for normal (synchronous) operation or TRUE to enqueue the request and resume control immediately. See Async I/O.
noErr (0) No error
nsvErr (-35) No such volume
paramErr (-50) No default volume
Notes: For most applications, the high-level GetVInfo function is sufficient for getting the free bytes and volume name. PBGetVInfo and the related
PBHGetVInfo return a lot more information.
The key to using this function is the ioVolIndex field. It will be:
positive (>0) An index; information about the n -th volume will be returned.
Volume indexes start with 1 and go up sequentially (until the
call returns nsvErr).
negative (<0) Use the ioNamePtr and/or ioVRefNum fields to specify the
desired volume in the standard way (if ioNamePtr is 0 or
invalid, ioVRefNum is used; if both are 0, the default volume is
assumed. Note that you must set ioVRefNum to 0, for ioNamePtr
to be used). If you are using ioNamePtr to specify a volume
name, the string must be in the following form
myVolParam.ioNamePtr = "\pMy HardDisk:
The trailing colon on the string indicates that we are referring
to a directory, not a file.
exactly 0 The ioVRefNum (alone) must specify the volume or a working
directory.
• If you use a working directory number, then on return
ioVNmFls will identify the number of files in that directory
• If you use a real volume number, then ioVNmFls will contain
the number of files in the root.
Upon return, ioVRefNum will contain a real volume number, unless you
used a working directory number on entry. Compare to PBHGetVInfo,
which always stores a real volume number in this field.
The ioNamePtr field itself is not changed. If it was not NIL on entry, then
the buffer it pointed to will receive a copy of the Pascal-style,
length-prefixed volume name (up to 27 characters long).
The returned fields, ioVNmAlBlks and ioVFrBlk, are clipped to 31744
(0x7C00), regardless of the TRUE size of the volume. The HFS function PBHGetVInfo does not have this size restriction.