Path: utzoo!attcan!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!rutgers!apple!dlyons
From: dlyons@Apple.COM (David Lyons)
Newsgroups: comp.sys.apple
Subject: Re: Directory modification dates
Keywords: GS/OS, directories, APW
Message-ID: <32362@apple.Apple.COM>
Date: 12 Jun 89 01:06:47 GMT
References: <8906040416.AA09109@crash.cts.com> <32248@apple.Apple.COM> <683@madnix.UUCP>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 28

In article <683@madnix.UUCP> jason@madnix.UUCP (Jason Blochowiak) writes:
>	Is it safe &&/|| reasonable to check the modification date of the
>parent directory (to find out if anything's changed)? It would seem that
>this would be significantly quicker vs. file checking when there weren't
>any changes (which it's assumed would be most of the time).
>[...]

No, it isn't safe under all conditions.  Although the ProDOS FST normally
propogates the mod-dates back up the tree all the way to the volume
directory under System Disk 5.0 (and up to the top subdirectory under
4.0, I *think*), ProDOS 8 (and ProDOS 16?) doesn't.

Note that the mod-dates show up in the result of GET_DIR_ENTRY, so it
isn't necessary to do a GET_FILE_INFO on each file.  This makes things
very reasonable if you need to see if a particular directory has
changed.  (If you need to do a whole disk, you still have a problem.)

>    jason@madnix.UUCP, methinks.     Formerly blochowi@garfield.cs.wisc.edu
>			"It beats working" - Harrison Ford

 --Dave Lyons, Apple Computer, Inc.          |   DAL Systems
   AppleLink--Apple Edition: DAVE.LYONS      |   P.O. Box 875
   AppleLink--Personal Edition: Dave Lyons   |   Cupertino, CA 95015-0875
   GEnie: D.LYONS2 or DAVE.LYONS         CompuServe: 72177,3233
   Internet/BITNET:  dlyons@apple.com    UUCP:  ...!ames!apple!dlyons

   My opinions are my own, not Apple's.