Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!auspex!guy
From: guy@auspex.auspex.com (Guy Harris)
Newsgroups: comp.unix.wizards
Subject: Re: Slashes in file names
Message-ID: <5828@auspex.auspex.com>
Date: 8 Feb 91 19:08:18 GMT
References: <25881@adm.brl.mil>
Organization: Auspex Systems, Santa Clara
Lines: 56

>I am fairly sure that the NFS spec does not contain any limitations
>on the file names, therefore a slash is allowed.

Yup.  It also allows backslashes, which will, I suspect really piss off
a DOS NFS server (yes, they exist) or an OS/2 NFS server.  It also
allows colons, which might piss off a Mac NFS server.  Etc., etc., etc..

>Given that, it seems that any system that is sold as a file server should
>have the utilities (other than just "dd") to handle the
>system administration of these files.

Either that, or not let you create them; that's what Suns have done
since SunOS 4.1, what Auspex boxes have done since whatever release I
put that fix in (I think it may have been in our first release), or what
some other UNIX-based NFS servers probably do as well.

Many boxes sold as file servers aren't sold *ONLY* as file servers, and
you may want to have files shared between machines with different OSes,
not all of which can cope with the same sorts of file names.

>I would like to hear suggestions for changes to the NFS spec.
>to solve this problem, since I can't think up any that work in
>the long run.

At one point, the NFS version 3 protocol spec included a request the
response to which enumerated which characters the server could *not*
cope with in file names.  If it had some other characters unlikely to
appear in file names, the client could then, when sending file names
to the server, use those characters in some way to replace the
characters the server can't cope with, and UNdo that operation when
*reading* file names from the server (e.g. in the "read directory"
request).

>Just to forestall some discussion:

Sorry, it won't work.

>1. Telling the Gatorbox to not allow slashes doesn't work.  I
>see too many files with names like "Expense Report 12/14/90".

Yes, it'd be unfortunate to tell users "sorry, you can't use file names
like that", but you may simply be stuck.  Life isn't always fair....

>2. Translating the slash just moves the problem to another 
>character.

Nope.  If the Mac can't cope with colons in file names (I think it's the
pathname separator on Macs, and a "Macintosh System Software User's
Guide, Version 6.0" here indicates that you can't use a colon in a file
name), if it replaces slashes in file names with colons (which UNIX can
deal with quite nicely) when it sends the names to a UNIX server, and
replaces colons with slashes when it gets names from a UNIX server, the
user on the Mac doesn't see any problem unless they try to tell a user
on some other system "please take a look at my file 'Expense Report
12/14/90'".  In that case, one or more of the users would have to be
aware that the name on their system might be 'Expense Report 12:14:90'".