On 2017-12-15 4:30 PM, Your Name wrote:
On 2017-12-16 00:10:04 +0000, Alan Baker said:

On 2017-12-14 4:31 PM, Your Name wrote:
On 2017-12-14 20:28:16 +0000, Andre G. Isaak said:
In article , Wolf K
wrote:
On 2017-12-14 10:18, nospam wrote:
In article , Tim
Streater
wrote:
| The type of a file and which app you'd like it to open
with are
| items
| of file metadata and have no business being part of the
filename.

| Many files have such type-identifiers included. E.g., a JPG file
| begins
| with JFIF, a WordPerfect file includes WPC in the first line,
an MS
| .doc

| Then you've put the metadata inside the file, which is even
worse. It
| should be part of the file system.

This is the problem with mixing Mac and Windows
discussions. As I understand it, Mac stores file data
separately as a "resource fork".

No, you have it back to front. File data went in the data fork,
metadata went in the resource fork.

no it didn't.

metadata was kept in the file system.

the resource fork (which was optional, as was the data fork) held
various resources. it was basically a miniature database.

a zero-length file would have an empty data *and* resource fork.
rare,
but possible.

Unfortunately Apple has abandoned
this idea and settled for the lowest-common-denominator approach,
and
w're all the worse off for it.

yep.

Educate me. What's the advantage of the "forks"? As described, it
looks
like metadata with a fancy name, apparently conceived as attached
to or
pointed to by the file. Presumably it's stored separately from the
file.

Resource Forks are completely unrelated to metadata.

The 2-fork architecture was inherited from Classic Mac OS, and, while
still supported by mac OS X, it is used much less frequently.

In Classic Mac OS, every file consisted of two separate forks
(either of
which could be empty).
snip

Wrong.

Purely data files, such as a JPEG image or Word document, did not
have any resource fork at all, not even an empty one. They didn't
need one because there are no resources. That's why if you try to
open a data file in ResEdit it says there is no resource fork and
asks if you want to add one. (An optional add-on did allow ResEdit to
open the data fork).

Mainly it was only applications that had resource forks.


Many people confuse the Finder's information as being part of the
resource fork, but they are different. The Finder's information is
not stored inside the file at all.

Would you care to explain, then, how the Finder knows what information
to apply to which file?

The Classic MacOS uses information stored within the Finder's own
invisible information files to understand what application to use with
each document file, the three usual ones being "Desktop DB", "Desktop
DF", and "TheVolumeSettingsFolder". These show up under Windows, which
was another cause of confusion for some users.


Yes, yes, yes...

.....I understand that very well.

But what is the SOURCE for the information in the first place?

And do you imagine that the Desktop DB, Desktop DF, etc. had individual
entries for EVERY FILE on a hard drive?

If not, then each FILE has to contain information about what KIND of
file it is.

This is why rebuilding the database was sometimes necessary to fix minor
quirks (such as incorrect icons, especially when creating custom icons).

MacOS X works in a similar way and has its Finder has different set of
invisible information files to keep track of such things.