Inside Macintosh: Files /

Chapter 2 - File Manager / File Manager Reference

High-Level HFS Routines / Opening Files

HOpenDF

You can use the HOpenDF function to open the data fork of a file.

FUNCTION HOpenDF (vRefNum: Integer; dirID: LongInt; 
                  fileName: Str255; permission: SignedByte; 
                  VAR refNum: Integer): OSErr;

vRefNum

A volume reference number, a working directory reference number, or 0 for the default volume.

dirID

A directory ID.

fileName

The name of the file.

permission

The access mode under which to open the file.

refNum

The file reference number of the opened file.

DESCRIPTION

The HOpenDF function creates an access path to the data fork of a file and returns, in
the refNum parameter, an access path reference number to that fork. You can pass that reference number as a parameter to any of the high-level file access routines.

RESULT CODES

noErr	0	No error
nsvErr	-35	No such volume
ioErr	-36	I/O error
bdNamErr	-37	Bad filename
tmfoErr	-42	Too many files open
fnfErr	-43	File not found
opWrErr	-49	File already open for writing
permErr	-54	Attempt to open locked file for writing
dirNFErr	-120	Directory not found or incomplete pathname
afpAccessDenied	-5000	User does not have the correct access to the file