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Groups > comp.arch.embedded > #18852

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 2014-10-20 09:45 -0700
Organization Aioe.org NNTP Server
Message-ID <m23e85$3jn$1@speranza.aioe.org> (permalink)
References <m18295$e3o$1@speranza.aioe.org> <m199ak.ao.1@stefan.msgid.phost.de>

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On 10/10/2014 9:42 AM, Stefan Reuther wrote:
> Don Y wrote:
>> Does anyone know which filesystem naming constraints are imposed
>> in Windows itself vs. the file system layer?  Said another way,
>> which constraints are *invariants* regardless of the filesystem?
>>
>> E.g., can a non-native filesystem redefine '+' to replace "../"?
>> Or, allow support for ':' in names?  Or, replace '\' with '/'?
>> Or, ...
>
> Here is what Microsoft has to say on the topic:
> http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247%28v=vs.85%29.aspx
>
> TL;DR, the reserved characters are
> - "\", "/" for the path separator
> - ":" for the drive letter separator, and to separate file names
>    and alternate data streams
> - "?" and "*" because they are used in wildcards
> - ">", "<", "|", and """ because they are used in shell syntax

C:\> cd \SfU

C:\SfU> mkdir XXX

C:\SfU> cd XXX

C:\SfU\XXX> PATH=..\bin

C:\SfU\XXX> touch AAA

C:\SfU\XXX> touch aaa

C:\SfU\XXX> touch A:a

C:\SfU\XXX> touch A'a

C:\SfU\XXX> touch A`a

C:\SfU\XXX> touch B?b

C:\SfU\XXX> touch C*c

C:\SfU\XXX> ls
A'a     A:a     AAA     A`a     B?b     C*c     aaa

It doesn't seem possible to embed redirection operators
in filenames regardless of quoting.  (e.g., A>a, A<a, A|a)
This differs from UN*X shells.  This suggests those operators
are processed early in Interix's shell -- before quoting!

Note that Windows Explorer lists these file names as above
with the exception that the ':' and '?' characters are presented
as a box and "C*c" appears as "Cc".

(IIRC, the "boxes" are not identical characters so "A:a" and
"A?a" would appear as two entries in the Explorer window yet
indicate different files.)

The more interesting issue is how Windows handles these
files when you try to manipulate any of them.  E.g.,
attempting to delete "AAA" will prompt you to delete "AAA"
and then "AAA" (aka "aaa")!

> The 'CreateFile' function refuses to create files with these names. It
> might be possible to use some lower-level interface to create such
> files, but that wouldn't get you much as no other program would be able
> to access them.

On the contrary, even Windows Explorer can SEE and ACCESS them!

C:\SfU\XXX> ls > foo

C:\SfU\XXX> cat foo
A'a     A:a     AAA     A`a     B?b     C*c     aaa     foo

C:\SfU\XXX> cp foo B?b

C:\SfU\XXX> rm foo

C:\SfU\XXX> ls
A'a     A:a     AAA     A`a     B?b     C*c     aaa

C:\SfU\XXX> cat B?b
A'a     A:a     AAA     A`a     B?b     C*c     aaa     foo

C:\SfU\XXX> mv B?b B?b.txt

C:\SfU\XXX> ls
A'a     A:a     AAA     A`a     B?b.txt C*c     aaa

Now, double-click on "B[box]b.txt" in Windows Explorer and see
the contents of foo.  (B?b.txt)

Unfortunately, the rules Windows (and Interix) seems to follow
aren't terribly obvious (on casual inspection).

I should try the same exercise from NFS (client and server)
to see how yet another vendor's code behaves under Windows.

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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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