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Inside Macintosh: Files /

Chapter 2 - File Manager / File Manager Reference

Shared Environment Routines / Opening Files While Denying Access

PBHOpenDeny

You can use the PBHOpenDeny function to open a file's data fork using the access
deny modes.

FUNCTION PBHOpenDeny (paramBlock: HParmBlkPtr; async: Boolean): 
                        OSErr;

paramBlock

A pointer to a basic HFS parameter block.

async

A Boolean value that specifies asynchronous (TRUE) or synchronous (FALSE) execution.

-->	ioCompletion	ProcPtr	A pointer to a completion routine.
<--	ioResult	OSErr	The result code of the function.
-->	ioNamePtr	StringPtr	A pointer to a pathname.
-->	ioVRefNum	Integer	A volume specification.
<--	ioRefNum	Integer	The file reference number.
-->	ioDenyModes	Integer	Access rights data.
-->	ioDirID	LongInt	The directory ID.

DESCRIPTION

The PBHOpenDeny function opens a file's data fork with specific access rights specified in the ioDenyModes field. The file reference number is returned in ioRefNum.

The result code opWrErr is returned if you've requested write permission and you
have already opened the file for writing; in that case, the existing file reference
number is returned in ioRefNum. You should not use this reference number unless
your application originally opened the file.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for PBHOpenDeny are

Trap macro	Selector
_HFSDispatch	$0038

RESULT CODES

noErr	0	No error
tmfoErr	-42	Too many files open
fnfErr	-43	File not found
fLckdErr	-45	File is locked
vLckdErr	-46	Volume is locked or read-only
opWrErr	-49	File already open for writing
paramErr	-50	Function not supported by volume
permErr	-54	File is already open and cannot be opened using specified deny modes
afpAccessDenied	-5000	User does not have the correct access to the file
afpDenyConflict	-5006	Requested access permission not possible