Re: 2 Macs -- 1 File

On Thu, 20 Jan 2011 16:24:50 -0000, "Graham J" <graham@invalid> wrote:

However, as others have explained, the surprising fact apears to be that
file system security is controlled by the application, not by the file
system. So an application can request "open file for read" - which should
succeed regardless of who else is using the file; or "open file for write"
which one might expect to fail if the file is already opened from elsewhere.
If the application chooses to ignore the "already open" state of the file
then corruption can occur.

I can't see any other reason why it appears to be "extra-unwise" to point
two copies of Filemaker at the same file.

My suspicion is that security enforced by the file system would be too slow,
so it's not done.

I don't think so - security enforced by the filesystem is very quick
indeed. Filemaker is an old app, from before Macs had any real
filesystem permissions or security. The MS Office apps are the same.

Although all are now OSX apps, and the OSX filesystem is fairly rich
in controls (basic unix user/group permissions, modern access lists,
tagged info items) I would be willing to bet that the reason those
apps do their own locking is simply because they haven't been
rewritten to take advantage of the OS they are now running on.

Cheers - Jaimie
--
Once I drove so fast that my friend, who was pregnant, started having
Lorentz contractions.

"Ahah," you might ask, "but how far apart were they?" - Adam Fineman, rgrn
.

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