Important: The information in this document is obsolete and should not be used for new development.
Working Directory Parameter Blocks
The low-level HFS functionsPBOpenWD
,PBCloseWD
, andPBGetWDInfo
use the working directory parameter block defined by theWDPBRec
data type.
TYPE WDPBRec = {working directory parameter block} RECORD qLink: QElemPtr; {next queue entry} qType: Integer; {queue type} ioTrap: Integer; {routine trap} ioCmdAddr: Ptr; {routine address} ioCompletion: ProcPtr; {pointer to completion routine} ioResult: OSErr; {result code} ioNamePtr: StringPtr; {pointer to pathname} ioVRefNum: Integer; {volume specification} filler1: Integer; {reserved} ioWDIndex: Integer; {working directory index} ioWDProcID: LongInt; {working directory user identifier} ioWDVRefNum: Integer; {working directory's vol. ref. num.} filler2: ARRAY[1..7] OF Integer; {reserved} ioWDDirID: LongInt; {working directory's directory ID} END;
Field Description
qLink
- A pointer to the next entry in the file I/O queue. (This field is used internally by the File Manager to keep track of asynchronous calls awaiting execution.)
qType
- The queue type. (This field is used internally by the File Manager.)
ioTrap
- The trap number of the routine that was called. (This field is used internally by the File Manager.)
ioCmdAddr
- The address of the routine that was called. (This field is used internally by the File Manager.)
ioCompletion
- A pointer to a completion routine to be executed at the end of an asynchronous call. It should be
NIL
for asynchronous calls with
no completion routine and is automatically set toNIL
for all synchronous calls. See "Completion Routines" on page 2-238 for information about completion routines.ioResult
- The result code of the function. For synchronous calls, this field is the same as the result code of the function call itself. To determine when an asynchronous call has actually been completed, your application can poll this field; it's set to a positive number when
the call is made and receives the actual result code when the call
is completed.ioNamePtr
- A pointer to a pathname. Whenever a routine description specifies that
ioNamePtr
is used--whether for input, output, or both--
it's very important that you set this field to point to storage for aStr255
value (if you're using a pathname) or toNIL
(if you're not).ioVRefNum
- A volume specification (volume reference number, working directory reference number, drive number, or 0 for default volume).
filler1
- Reserved.
ioWDIndex
- An index for use with the
PBGetWDInfo
function.ioWDProcID
- An identifier that's used to distinguish between working directories set up by different users; you should set
ioWDProcID
to your application's signature.ioWDVRefNum
- The working directory's volume reference number.
filler2
- Reserved.
ioWDDirID
- The working directory's directory ID.
© Apple Computer, Inc.
2 JUL 1996