Re: Filesystem syntax constraints under Windows

From	Don Y <this@is.not.me.com>
Newsgroups	comp.arch.embedded
Subject	Re: Filesystem syntax constraints under Windows
Date	2014-10-10 10:53 -0700
Organization	Aioe.org NNTP Server
Message-ID	<m196n3$f0a$1@speranza.aioe.org> (permalink)
References	(1 earlier) <m187i5$rav$1@speranza.aioe.org> <m18g3o$u4o$1@dont-email.me> <m18qdl$ckj$1@speranza.aioe.org> <m18qj7$ckj$2@speranza.aioe.org> <m190q4$e3$1@dont-email.me>

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Hi Dimiter,

[Sort out your display/tablet issue, yet?]

On 10/10/2014 9:17 AM, Dimiter_Popoff wrote:
>>> So, the exported namespace can represent:
>>>      some/very/long/traditional/pathname/to/a/file as "file"
>>>      some/other/file as "file2"
>>>      some.particular\method as "verb"
>>>      That(&*^@$%(Fool as "A_Fine_Gentleman"
>>
>> In case it wasn't obvious:  to the "external system", this LOOKS
>> like a single "directory" with four names in it.  It is *flat*!
>> (despite the fact that the objects all existed at different
>> "places"/levels in the system exporting them)

> as David already suggested your best chance is to limit what you
> accept (and thus have to process) as much as practical.

That's exactly what I *don't* want to do!

I want an object to be able to define the rules for what constitutes
a legitimate identifier IN IT'S SCOPE in whatever manner it wants.
For example, an IPv6 address should be allowed in the namespace
(of an object that expects to deal with IPv6 addresses!).  You shouldn't
have to map some character with arbitrarily imposed "special meaning"
(e.g., ':') to some OTHER character -- just because the filesystem's
naming rules didn't anticipate using it *in* an identifier.

[Ditto '/' or '\']

> The problems are by far not just related to how this or that
> character is treated; e.g. at the moment I am struggling with
> how I process names in _my_ dps scripts using _my_ longnamed directories
> to be compatible with _my_ older 8.4 directories.

If, OTOH, you had a more permissive implementation *before*, then
this problem wouldn't exist!

E.g., filenames of the form ".cshrc" annoy Windows (though you can
*trick* it to accept them... you just can't always *create* files
having such names).

Likewise, I often encounter cases where I am importing a set of files
created under UN*X and find name collisions where names differ only
by issues of case.  It seems counterintuitive to come up with a new
scheme that has *less* capability than an existing one.  :-/

> The worst issue
> I have is with names containing spaces; treating those in a script
> makes word count variable, preserving space count between words must
> be addressed, forwarding a name which was in quotation marks which
> get "eaten" during the former processing etc. etc. If you can
> afford to disallow spaces in names things will be much simpler.
> Which is not really practical as other systems do allow spaces,
> so we have to handle this as well.

Exactly.  Building on what you say below, should we just ignore
embedded whitespace (just like ignoring alphabetic case?).
So, "Avery Littleman" and "A Very Little Man" and "AVERYLITTLEMAN"
are all the same?  :-/

> As a side note, "the right way" to treat file names is to preserve
> the case information and to ignore it during file search (i.e.
> aaa and AAA locate the same file). Obviously unix machines will
> have the improper case treatment problem forever but it is
> their problem after all, they have saved a few minutes of
> thinking back when they created it. My solution to that was to
> do the right thing and allow also the wrong thing to be done;
> i.e. if you compare the textual part of the name (which is stored
> as upper (or was it lower) case only) you locate the same file,
> if you want to distinguish also by case you have to compare
> another few bytes which carry the case bits for the textual
> part. But I am not sure I even made a call doing the case dependent
> search, if I do I have never used it so far anyway.

I disagree.  And, I think your comments reflect a particular manner in
which you see filenames used.  I.e., exposed to the user to name
objects (files) that he has created.

I use names to identify objects that a piece of software (process)
can access.  Each process is created with its own, "personal"
namespace which has been populated by its parent/creator (and, in
doing so, *bound* to specific existing system objects known to its
parent).

So, a TOP LEVEL namespace might be:
    My PID
    stdin
    stdout
    stderr
    My kmem
    My Files/
    garage door

The process that that namespace serves is responsible for knowing which
names are important to it.  It's not like exposing an entire filesystem
to a user so he can indicate which *file* (collection of bytes on a medium)
he wants to access.

Instead, they are conventions (for the most part) that the parent knows
the child will observe.  So, the parent can bind "stderr" to the "stdin"
of some other process (with a completely disjoint namespace) and know
that the childs error messages will be processed by that "other" process.

Note that, in my scheme, you are free to implement a "user visible container
for files" (i.e., "a folder") and impose an entirely different set of
rules, therein.  When someone/thing tries to "walk" (parse_pathname)
through that folder, the method associated with that type of object
("user visible container for files") can opt to ignore case.  Or, treat
numbers as Roman numeral equivalents.  Or...

OTOH, if you impose some restriction on the *basic* name scheme, you
can never "enhance" it (without a lot of compatibility grief).

Thread

Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-10 00:31 -0700
  Re: Filesystem syntax constraints under Windows glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-10-10 09:06 +0000
    Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-10 13:32 +0200
      Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-10 07:23 -0700
        Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-10 07:26 -0700
          Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-10 19:17 +0300
            Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-10 19:12 +0200
              Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-10 20:34 +0300
              Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-10 11:32 -0700
            Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-10 10:53 -0700
              Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-10 21:24 +0300
                Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-10 13:36 -0700
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-11 00:18 +0300
                Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-10 15:28 -0700
                Re: Filesystem syntax constraints under Windows Tonton Th <tTh@nowhere.invalid> - 2014-10-12 20:07 +0000
                Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-12 19:52 -0700
              Re: Filesystem syntax constraints under Windows Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2014-10-10 21:15 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-10 23:04 +0300
            Re: Filesystem syntax constraints under Windows Stefan Reuther <stefan.news@arcor.de> - 2014-10-11 11:28 +0200
              Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-11 17:13 +0300
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-11 17:26 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-11 18:51 +0300
                Re: Filesystem syntax constraints under Windows Stefan Reuther <stefan.news@arcor.de> - 2014-10-12 12:04 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-12 15:59 +0300
                Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-12 08:04 -0700
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-12 18:47 +0300
                Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-12 09:01 -0700
                Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-12 09:05 -0700
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-12 19:17 +0300
                Re: Filesystem syntax constraints under Windows Stefan Reuther <stefan.news@arcor.de> - 2014-10-13 19:26 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-13 22:00 +0300
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-14 10:25 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-14 13:28 +0300
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-14 14:37 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-14 16:00 +0300
                Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-14 06:19 -0700
                Re: Filesystem syntax constraints under Windows Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2014-10-15 19:57 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-16 00:06 +0300
                Re: Filesystem syntax constraints under Windows Stefan Reuther <stefan.news@arcor.de> - 2014-10-16 18:16 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-16 20:49 +0300
                Re: Filesystem syntax constraints under Windows Stefan Reuther <stefan.news@arcor.de> - 2014-10-14 18:59 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-14 21:39 +0300
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-14 23:29 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-15 00:46 +0300
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-15 01:38 +0200
        Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-10 17:31 +0200
          Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-10 10:34 -0700
    Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-10 06:59 -0700
  Re: Filesystem syntax constraints under Windows Stefan Reuther <stefan.news@arcor.de> - 2014-10-10 18:42 +0200
    Re: Filesystem syntax constraints under Windows glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-10-10 19:00 +0000
    Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-10 13:43 -0700
      Re: Filesystem syntax constraints under Windows upsidedown@downunder.com - 2014-10-11 11:06 +0300
        Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-11 01:35 -0700
        Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-11 17:24 +0300
        Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-11 17:43 +0200
          Re: Filesystem syntax constraints under Windows Stefan Reuther <stefan.news@arcor.de> - 2014-10-12 12:07 +0200
            Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-12 23:41 +0200
              Re: Filesystem syntax constraints under Windows Stefan Reuther <stefan.news@arcor.de> - 2014-10-13 19:14 +0200
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-13 20:18 +0200
                Re: Filesystem syntax constraints under Windows Mel Wilson <mwilson@the-wire.com> - 2014-10-15 18:43 +0000
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-15 21:58 +0200
                Re: Filesystem syntax constraints under Windows George Neuner <gneuner2@comcast.net> - 2014-10-15 23:55 -0400
    Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-20 09:45 -0700
      Re: Filesystem syntax constraints under Windows Stefan Reuther <stefan.news@arcor.de> - 2014-10-21 18:47 +0200
        Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-21 15:38 -0700
          Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-21 17:51 -0700
          Re: Filesystem syntax constraints under Windows George Neuner <gneuner2@comcast.net> - 2014-10-22 01:35 -0400
            Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-21 23:22 -0700
              Re: Filesystem syntax constraints under Windows Stefan Reuther <stefan.news@arcor.de> - 2014-10-22 18:39 +0200
                Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-22 11:34 -0700
                Re: Filesystem syntax constraints under Windows upsidedown@downunder.com - 2014-10-22 22:11 +0300
            Re: Filesystem syntax constraints under Windows glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-10-23 00:20 +0000
              Re: Filesystem syntax constraints under Windows George Neuner <gneuner2@comcast.net> - 2014-10-23 01:36 -0400
                Re: Filesystem syntax constraints under Windows glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-10-23 09:08 +0000
                Re: Filesystem syntax constraints under Windows George Neuner <gneuner2@comcast.net> - 2014-10-23 14:50 -0400
                Re: Filesystem syntax constraints under Windows Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2014-10-23 21:42 +0200
      Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-22 01:21 +0300
        Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-21 15:51 -0700
          Re: Filesystem syntax constraints under Windows glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-10-21 23:27 +0000
            Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-21 16:50 -0700
            Re: Filesystem syntax constraints under Windows Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2014-10-22 21:00 +0200
              Re: Filesystem syntax constraints under Windows upsidedown@downunder.com - 2014-10-22 22:54 +0300
          Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-22 02:32 +0300
            Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-21 17:21 -0700
              Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-22 03:52 +0300
                Re: Filesystem syntax constraints under Windows Don Y <this@is.not.me.com> - 2014-10-21 21:13 -0700
            Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-22 08:10 +0200
              Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-22 12:00 +0300
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-22 13:11 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-22 15:19 +0300
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-22 15:21 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-22 17:26 +0300
                Re: Filesystem syntax constraints under Windows Stefan Reuther <stefan.news@arcor.de> - 2014-10-22 18:46 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-23 02:37 +0300
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-22 23:09 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-23 03:06 +0300
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-23 10:18 +0200
                Re: Filesystem syntax constraints under Windows Dimiter_Popoff <dp@tgi-sci.com> - 2014-10-23 13:56 +0300
                Re: Filesystem syntax constraints under Windows David Brown <david.brown@hesbynett.no> - 2014-10-23 15:59 +0200

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