What kinds of things would you want in the GNU OS?
Mike Mitchell
mcm at rti.UUCP
Sat Jun 10 01:37:24 AEST 1989
I have been reading the articles proposing different symantics for accessing
remote systems with some amusement. Some say '//host', others '@/host' or
'/@host' or other varients. All require some hackery to the name parsing
routines in the kernel (namei) so that it recognises some new syntax. Why
not use the notation '/../system'? There have been distributed systems using
this form since at least 1982. An example of one is described in "The Newcastle
Connection - or UNIXes of the World Unite," Software - Practice and Experience,
vol. 12, December 1982.
Let me explain a bit about the '/../system' symantic. The '/' is your normal
root, right? What is the convention for directory entries '.' and '..' in V7,
System V, and BSD unix systems? Isn't '.' just a hard link to the current
directory? Isn't '..' just a hard link to the parent of the current directory?
Now in the directory called '/', the entry '..' is a hard link to the current
directory also. What happens if you unlink the '..' entry in the '/' directory
and mkdir a directory called '..'? I'll tell you what happens. You get a
directory called '..' accessible from '/'. You can now chdir to '/..' and
get to a new directory. Put anything you want in that directory. Put
symbolic links pointing to NFS systems there. Put mount points for NFS there.
Put the '/dev/net/systemname' character/block devices there. It really doesn't
matter what you put there, because it is just another directory. UNIX users
are used to '..' meaning go up a directory. To go to another system, you should
go above the root on your own system, then down to another one ('/../system').
It all just makes sense.
Of course, if you want to extend a local group of systems into a larger
collection of systems, just add another '..' directory to the '/..' directory.
Then the hierarchy could be like '/../nearsystem', '/../../virgina/system',
'/../../oregon/system', '/../../../england/london/system', or any other kind
of subdivision. The tree could just keep going up.
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