ParentDir

Obtain the parent of a directory or file

The argument 'lock' is associated with a given file or directory. ParentDir() returns 'newlock' which is associated with the parent directory of 'lock'.

Taking the ParentDir() of the root of the current file system returns a NULL (0) Lock. Note this NULL Lock represents the root of the file system that you booted from (which is, in effect, the parent of all other file system roots.)

lock

BCPL pointer to a Lock

newlock

BCPL pointer to a Lock; a value of NULL may be returned if ParentDir() failed, but NULL may also be returned if the Lock for which you called ParentDir() has no parent directory itself. Call the IoErr() function to find out whether ParentDir() failed because of an error or if the Lock you used has no parent directory. The difference is that in the latter case, IoErr() will always return 0.

Lock(), DupLock(), UnLock(), ParentOfFH(), DupLockFromFH(), IoErr()