Inside Macintosh: Files /

Chapter 2 - File Manager / File Manager Reference

High-Level Volume Access Routines / Obtaining Volume Information

GetVRefNum

You can use the GetVRefNum function to get a volume reference number from a file reference number.

FUNCTION GetVRefNum (refNum: Integer; VAR vRefNum: Integer): 
                     OSErr;

refNum

The file reference number of an open file.

vRefNum

On exit, the volume reference number of the volume containing the file specified by refNum.

DESCRIPTION

The GetVRefNum function returns the volume reference number of the volume containing the specified file. If you also want to determine the directory ID of the specified file's parent directory, call the PBGetFCBInfo function.

RESULT CODES

noErr	0	No error
rfNumErr	-51	Bad reference number