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From: ccplumb@watmath.UUCP
Newsgroups: comp.sys.amiga
Subject: Re: Putting devices in the filename space
Message-ID: <14943@watmath.waterloo.edu>
Date: Wed, 31-Dec-69 18:59:59 EDT
Article-I.D.: watmath.14943
Posted: Wed Dec 31 18:59:59 1969
Date-Received: Wed, 30-Sep-87 01:20:30 EDT
References: <503@louie.udel.EDU> <1929@umd5.umd.edu> <775@sugar.UUCP> <5176@jade.BERKELEY.EDU> <805@sugar.UUCP> <5218@jade.BERKELEY.EDU> <8365@shemp.UCLA.EDU>
Reply-To: ccplumb@watmath.waterloo.edu (Colin Plumb)
Organization: U of Waterloo, Ontario
Lines: 40
Confusion: U. of Waterloo, Ontario

Myself, I prefer the Unix-like single-root system.  Just because Unix
can't handle removable media is no reason not to be able to use
Unix-like syntax and variable-position mounting in AmigaDOS.  If I
'mount /dev/df1 /fish103', eject the disk, then try to do something
with /fish103/unix/README (you didn't know there was a full 4.3 Unix on
disk #103, did you? :-)), it can just pop up a requester:

	-------------------------
	| Please insert disk	|
	| "Fish 103"		|
	| (mounted on /fish103)	|
	-------------------------

The syntax conventions don't preclude removable media.  Each AmigaDOS
device can still interpret paths within itself as it wishes.  Thus, I
could use /dev/con/10/10/200/200, /dev/inet/[whatever goes here], etc.
Only disk-like devices need support mounting.

As to implementaton, hm...  Essentially, you'd need some system for
marking certain directories as being link points to certain devices.
The Unix method is to set a bit in the inode telling the system to have
a look through the mount table.  A good way would probably to create a
special sort of file which contains a pointer to the device mounted
here.  mount would create the file and unmount would delete it.

The only other change required would be a change in the syntax AmigaDOS
eats.  While you were at it, you could implement . and .. - not as
links, but simply as special strings recognized by the filename parser
for disk-like devices.  (There really isn't any need to have them
present in the directory.  All that does is adds special code to find
and its relatives.  ".." is already hard-coded into Minix (in the code
which handles "cd .." across mount points).  Probably Unix, too.

I can't *really* tell how this could be integrated into AmigaDOS.  I'm
not too familiar with AmigaDOS innards - its ugliness (e.g. BCPL) has
prevented me from learning about it.
--
	-Colin Plumb (watmath!ccplumb)

HELLO, everybody, I'm a HUMAN!!