File daemons

[Karl Kleinpaste]

flee at shire.cs.psu.edu writes:
   > The obvious fully-general solution is to allow arbitrary functions
   > to be attached to files, to perform any kind of authentication
   > checking or audit trails that the file's owner might desire.

   Scott Schwartz <schwartz at cs.psu.edu> has been randomly working on a
   daemon that implements access control lists.  The idea is, if you want
   to open a file you don't normally have access to, you ask the daemon
   to open it for you, and it will give you an open file descriptor

This has already been done.  See, for example, "Watchdogs: Extending
the UNIX File System," by Brian N Bershad & C Brian Pinkerton, Winter
88 (Dallas) Usenix Proceedings (and a later version of the same paper
in Vol 1 No 2 of _Computing_Systems_).

--Karl