HOpenDF

Create an access path to the data fork of a file

#include <Files.h> File Manager

OSErr HOpenDF(vRefNum , dirID, filename, permission, refNum);

short vRefNum ; a volume or working directory reference number

long dirID ; the directory ID

ŸStr255 filename ; name of the file to open

Ÿchar permission ; permission level

Ÿ short * refNum ; points to the path reference number

returns Error Code; 0=no error

HOpenDF creates an access path to the data fork of a file. It is an HFS version

of the function OpenDF.

vRefNum a volume or working directory reference number

dirID is the directory reference number.

filename is the name of the file to open

permission set this parameter to request the kind of access path permission you

want.

refNum points to a path reference number

Returns: an operating system Error Code. It will be one of:

noErr (0) No error

bdNamErr (-37) Bad name

extFSErr (-58) External file system

ioErr (-36) I/O error

nsvErr (-35) No such volume

opWrErr (-49) File already open for writing

tmfoErr (-42) Too many files open

Notes: HOpenDF takes a permission parameter

In most cases, you can simply set the permission parameter to fsCurPerm.

Some applications request fsRdWrPerm, to ensure that they can both read

and write to a file. The constants that can be passed in this field are the

following:

fsCurPerm exclusive read/write permission if it is available;

otherwise, exclusive read, if that is available

fsRdPerm exclusive read permission

fsWrPerm exclusive write permission

fsRdWrPerm exclusive read/write permission

fsRdWrShPerm shared read/write permission

In shared environments, permission requests are translated into the

"deny-mode" permissions defined by AppleShare.

Referenced by (4):