Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!iuvax!rutgers!unix!animal From: animal@unix.SRI.COM (Chan Wilson) Newsgroups: comp.sys.apple2 Subject: Re: Logical file linking? Message-ID: <13009@unix.SRI.COM> Date: 11 Jun 90 10:30:09 GMT References: <1990Jun1.190541.2119@helios.physics.utoronto.ca> <13041@smoke.BRL.MIL> <1990Jun4.014522.1843@laguna.ccsf.caltech.edu> <318@iczer-1.UUCP> Reply-To: animal@unix.UUCP (Chan Wilson) Organization: SRI International, Menlo Park, CA Lines: 40 In article <318@iczer-1.UUCP> emm@iczer-1.UUCP (Edward M. Markowski) writes: [hard vs soft links nuked] > >Why can't a program just write a new directory entry >that points to the same data blocks as the orginal? What do you do when you delete one of the files? ProDOS as it stands will mark the blocks as free, leaving the other links out on a limb. You'd need to stuff a link counter in the file header someplace. Trouble is, there isn't much space. The only entries that you could bump would be the version or minimum-version fields. I think one of those is used to indicate upper/lowercase in the filename. To link subdirs, there's a little more freedom in the header, but the problem is they're all 'reserved' bytes. But the big problem, even if you do find space to stuff the link counter, is that you'd have to patch prodos and the prodos fst. This means you've got to decompile it, since Apple doesn't distribute source code, or entry points for this type of thing. I can't see any reason why such a mechanism couldn't be implimented, though.. >Edward M. Markowski -- iczer-1 Administrator > > ...the garage is flooded from the sprinkler. > It also left a man's decapitated body, >VOICE : (201) 478-6052 lying on the floor next to his own severed head. >UUCP : ..!uunet!iczer-1!emm A head which at this time has no name. ...I know its name... --Chan ................ Chan Wilson -- cwilson@nisc.sri.com I don't speak for SRI. Janitor/Architect of comp.binaries.apple2 archive on wuarchive.wustl.edu "a2fx it!" ................