Groups > comp.lang.java.programmer > #9973

Re: A strange behaviour of a File property

From	Eric Sosman <esosman@ieee-dot-org.invalid>
Newsgroups	comp.lang.java.programmer
Subject	Re: A strange behaviour of a File property
Date	2011-11-16 08:10 -0500
Organization	A noiseless patient Spider
Message-ID	<ja0cnc$k25$1@dont-email.me> (permalink)
References	(9 earlier) <slrnjc2kgb.fvg.avl@gamma.logic.tuwien.ac.at> <j9sk2u$f51$1@dont-email.me> <slrnjc4t4g.fvg.avl@gamma.logic.tuwien.ac.at> <j9va5b$890$1@dont-email.me> <slrnjc7a8j.fvg.avl@gamma.logic.tuwien.ac.at>

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On 11/16/2011 7:14 AM, Andreas Leitgeb wrote:
>[...]
> If in a VMS-shell you're curently in directory
>    data:[a.b.c.d.e.f.g.h.i.j.k.l.m.n]foo.dir
> and wanted to access the file
>    data:[a.b.c.d.e.f.g.h.i.j.k.l.m.n.bar]xyz.txt
> would you need to specify the complete path to xyz.txt, or
> is there some syntactic pendant to "../bar/xyz.txt" in VMS?

     Sorry; I don't remember.  I *do* remember, though that there
is no such thing as being "in" a directory.  VMS does not have a
Unix-oid notion of "current working directory," but instead has a
"default file specification."  If you hand the system an incomplete
file name, the missing pieces are filled in from the DFS.  Thus,
the resolution of incomplete names is a lexical operation, not a
"navigational" operation.

     Usually this difference does not obtrude itself upon the user's
consciousness, but there are situations where it becomes important.
For example, the "data" in your example could be a "logical name"
with multiple translations: DISK1:[ANDREAS],DISK2:[READONLY], for
example.  You could then tell javac to compile DATA:[.SOURCE]FOO.JAVA
and DATA:[.SOURCE]BAR.JAVA, and javac would happily find your locally-
modified DISK1:[ANDREAS.SOURCE]FOO.JAVA and the still-in-the-repository
DISK2:[READONLY.SOURCE]BAR.JAVA.  It's something like the way a Unix
shell follows the PATH variable, except generalized for all files
instead of being limited just to executables.

     ... but note what this does to the notion of "current directory."
DATA:[.SOURCE]FOO.JAVA and DATA:[.SOURCE]BAR.JAVA have different
parent directories, DISK1:[ANDREAS] and DISK2:[READONLY], respectively.
The idea of being "in" a particular directory may not stand scrutiny.

-- 
Eric Sosman
esosman@ieee-dot-org.invalid

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A strange behaviour of a File property alelvb@inwind.it - 2011-11-11 05:45 -0800
  Re: A strange behaviour of a File property Lew <lewbloch@gmail.com> - 2011-11-11 07:34 -0800
    Re: A strange behaviour of a File property alelvb@inwind.it - 2011-11-11 09:28 -0800
      Re: A strange behaviour of a File property Lew <lewbloch@gmail.com> - 2011-11-11 14:17 -0800
        Re: A strange behaviour of a File property alelvb@inwind.it (Alexo) - 2011-11-12 15:04 +0100
          Re: A strange behaviour of a File property Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-12 09:15 -0500
            Re: A strange behaviour of a File property alelvb@inwind.it (Alexo) - 2011-11-12 16:17 +0100
              Re: A strange behaviour of a File property Zlatko Đurić <zladuric@gmail.com> - 2011-11-12 16:09 +0100
              Re: A strange behaviour of a File property Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-12 10:13 -0500
  Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-11 16:25 +0000
    Re: A strange behaviour of a File property alelvb@inwind.it - 2011-11-11 09:42 -0800
      Re: A strange behaviour of a File property Arne Vajhøj <arne@vajhoej.dk> - 2011-11-11 13:24 -0500
    Re: A strange behaviour of a File property Lew <lewbloch@gmail.com> - 2011-11-11 14:13 -0800
    Re: A strange behaviour of a File property Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-11 20:38 -0500
      Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-12 03:21 +0000
        Re: A strange behaviour of a File property Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-12 08:26 -0500
          Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-12 22:09 +0000
            Re: A strange behaviour of a File property Arne Vajhøj <arne@vajhoej.dk> - 2011-11-12 17:40 -0500
              Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-13 01:28 +0000
                Re: A strange behaviour of a File property Arne Vajhøj <arne@vajhoej.dk> - 2011-11-12 20:42 -0500
                Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-13 12:15 +0000
                Re: A strange behaviour of a File property Martin Gregorie <martin@address-in-sig.invalid> - 2011-11-13 12:42 +0000
                Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-13 13:06 +0000
        Re: A strange behaviour of a File property Arne Vajhøj <arne@vajhoej.dk> - 2011-11-12 17:25 -0500
          Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-13 01:15 +0000
            Re: A strange behaviour of a File property Arne Vajhøj <arne@vajhoej.dk> - 2011-11-12 20:40 -0500
              Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-13 12:42 +0000
            Re: A strange behaviour of a File property Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-12 21:11 -0500
              Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-13 20:50 +0000
                Re: A strange behaviour of a File property Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-14 08:18 -0500
                Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-14 17:38 +0000
                Re: A strange behaviour of a File property Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-14 21:51 -0500
                Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-15 14:17 +0000
                Re: A strange behaviour of a File property Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-15 22:20 -0500
                Re: A strange behaviour of a File property Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-16 12:14 +0000
                Re: A strange behaviour of a File property Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-16 08:10 -0500
      Re: A strange behaviour of a File property Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-11-11 19:46 -0800
      Re: A strange behaviour of a File property Owen Jacobson <angrybaldguy@gmail.com> - 2011-11-14 00:24 -0500
        Re: A strange behaviour of a File property Lew <lewbloch@gmail.com> - 2011-11-13 22:00 -0800
  Re: A strange behaviour of a File property Roedy Green <see_website@mindprod.com.invalid> - 2011-11-12 05:00 -0800
    Re: A strange behaviour of a File property Arne Vajhøj <arne@vajhoej.dk> - 2011-11-12 09:15 -0500

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