Hi Kurt:
Prior to Sys 10, Mac users never had to know what a file extension was.
I always assumed they brought it in because it was necessary to Windows
machines to see when the file was brought from a Mac to a PC.
Not so: They bought it in because Unix wants it. You can't actually have a
Unix File System without it, although Unix does not require files to have
extensions, provided that you are willing to forego the ability to
double-click things in the Finder... Don't you just love consistency?
The ability to read the Creator Code and Mac ID is replicated in OS X by an
application module that is external to the BSD core. BSD Unix expects and
needs file extensions.
Windows does exactly the same, except that they can pretend that the module
is part of Windows (well, it *is* part of Windows, but you could come up
with a philosophical argument that it 'shouldn't' be
)
Either way, Windows these days flies mainly on the file header, which is
contained in the first 500-ish bytes of the file (it's not normally that
big...).
For either of them, this slows things down: The system has to read the disk
directory to find the file name, then read the disk to find the file, then
open the file and read in the first block, then parse the block to work out
what's in the file, then close the file and hand it off to the destination
application. It's a very laborious way of working, brought to you by people
who need to convince you that you need a new computer that is faster than
the old one
If the file name has an extension, the system needs read only the name, then
open the destination application and pass the location of the unopened file
to the application. Much more efficient, but not as 'safe'. If users lie
about what's in the file by adding the wrong extension, the system gets very
confused
Cheers
--
Please reply to the newsgroup to maintain the thread. Please do not email
me unless I ask you to.
John McGhie <john@mcghie.name>
Microsoft MVP, Word and Word for Macintosh. Consultant Technical Writer
Sydney, Australia +61 4 1209 1410