mapping files to objects

cwg@DeepEddy.Com cwg@DeepEddy.Com
Tue, 06 May 1997 14:45:27 -0500


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> Yes.  Did you ever look to how MacOs is capable to handle
> MacOs files (resource fork + data fork) stored on an Unix system ?
> 
> The point being that, If we define that files (not pathnames) _do_
> contain types and other properties, we could then take the same
> approach MacOs does:
> 
> for each MacOs file there are really two files on the host system:
> 
> 1 file for the resource fork, which makes sense _only_ to MacOs
> 1 file for the data fork, which can be available to any application
>   capable to understand the host file-system.
> 
> Example, a Lisp source file called foo would then be stored on the
> host filesystem into:
> 
> foo.<lispos-resource>	lispos relevant info as the file type
> foo			the ascii file
> 
> so that, every OS will be capable to use foo, but only LispOs
> will take advantage of foo.<lispos-resource>.
> 
> When MacOs does this on Unix, you have the following situation:
> 
> if foo is under /my-disk/my-job/
> 
> then foo is store as /my-disk/my-job/foo and foo.<lispos-resource>
> is stored as /my-disk/my-job/.<lispos-resources>/foo

The (possibly misguided) thought that I had was to avoid having to read the 
file to get information that should properly be in the directory entry.  
(Of course, you could probably convince me that type information doesn't 
belong in the directory entry.)

Actually, this seems like a good idea anyway.  Think it would be worth trying 
to be compatible with MacOS files, or should our resources file contain a
more lispy structure?

Whatever we do, I want to make sure that it's possible for me to determine 
that the files in /var/spool/mail are mbox files w/o having to put anything 
additional in that directory.

Chris

-- 
Chris Garrigues                    O-              cwg@DeepEddy.Com
  Deep Eddy Internet Consulting                     +1 512 432 4046
  609 Deep Eddy Avenue
  Austin, TX  78703-4513              http://www.DeepEddy.Com/~cwg/



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