[comp.sys.apple] sparse ProDOS files/telcom

dlyons@Apple.COM (David Lyons) (09/01/89)

>Date: Thu, 31 Aug 89 10:38:14 -0400 (EDT)
>From: Brendan Gallagher Hoar <bh1e+@andrew.cmu.edu>
>
>[...] Hmmm...a neat way of copy protecting files...
>make it sparse, and have it check its size before running...anything that was
>copied under ProDOS 8 or transmitted over a modem ends up not working...

Probably not a very good idea:  for one thing, all you'd have to do to get
around the "protection" is copy the file in the Finder.  Presto!  Sparse
again.  (Or receive it under a GS/OS telcom program, or unarchive it under
a GS/OS unarchiver.)

Besides...by checking for a particular block count you have a good chance
of *preventing* your GS/OS program from running under any present or future
non-ProDOS file systems.

>I had thought that only text files could be sparse...guess I was wrong...

Right--any nondirectory file on a ProDOS volume can be sparse, regardless
of its filetype.

 --Dave Lyons, Apple Computer, Inc.          |   DAL Systems
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