In reply to Luke McNeilage's message of the 01/06/2000 at 17:43 +1000,


>On one Macintosh make an alias of a file off my NT server.
>Store that alias three directories deep.
>open that directory on another Macintosh.
>double click on the alias,
>and it will prompt me to login to the NT Server.

Um, if you bothered to read the list like you tell everyone to, you'd 
know that NT file services for Macintosh is one of the few to support 
file and directory IDs (ie aliases to you).

On netatalk volumes, for example, aliases to a folder inside a volume 
work fine until you do something to change the directory structure. 
Try this:

1) create a folder on a netatalk vol, call it test
2) make an alias to it onto a local disk
3) dbl-click on the alias and it should open the folder on the 
mounted vol; unmount the netatalk vol, dbl-click the alias and it 
should re-mount the netatalk volume for you. So far so good
4) Now create a new folder called test1,and move the test folder 
inside the new one
5) dbl-click the alias and check that it still works (cool, no? 
Sym-links don't do this.)
6) Now re-boot the Mac; when it comes back up, dbl-click on the the 
alias. It will either say it can't be found, open a completely 
different folder or if you're dead lucky it will re-open the test 
folder. It all depends on whether netatalk has re-assigned it the 
same directory ID. In the case of the last, create another folder, 
test2, move the test folder to it, delete test1, reboot and try 
again. It will fail eventually.

If this test sounds artificial, remember that on a busy server, users 
will be creating and deleting folders all the time.

As for:

>Its ill-advised information like this that causes distress
>
>Quark does not save aliased link, and the Mac OS just works more efficiently

I'm sorry I picked a bad example in Quark: my memory isn't what it 
was or perhaps they've changed the file format since I last did any 
serious work with Q Express (v3! I was debugging an OPI server and QX 
gave us no end of grief, but that's another story). If I'd been 
thinking I would have realized that none of the appls with 
cross-platform file formats would keep alias records* in their data 
files (since this would not be supported on other platforms). 
Nevertheless, there are plenty of Mac appls that do esp in prefs 
files. For example, Apple- (nee Claris-) Works uses alis records to 
locate its spelling dictionaries. So if a bunch of users wanted to 
share a common dict on a netatalk volume, too bad. And so on.

My point is that as a user, you have no control over this. It's great 
that most of the commonly used appls don't do this, but as a 
sysadmin, you can be pretty sure that some user will ring you up one 
day and say, "the XXX appl works if I sav eto my disk but not the 
file server". Of course, Murphy's law says that it will be your boss 
or biggest client and it will be their favourite PIM/drawing 
program/something absolutely essential.

Why do appls use alis records to track files? For one thing, 
pathnames aren't sufficient on MacOS: you can have more than 1 
mounted volume with the same name. Besides, Apple tells you to - 
there's a tech note somewhere that recommends to developers that 
appls save alis'es instead of pathnames.

* See chapter 4 of "Inside Macintosh: Files"

-- 
Sak Wathanasin
Network Analysis Limited
178 Wainbody Ave South, Coventry CV3 6BX, UK

Internet: [EMAIL PROTECTED]
Phone: (+44) 24 76 41 99 96        Mobile: (+44) 79 70 75 19 12 
Fax: (+44) 24 76 69 06 90

Reply via email to