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Re: A "current directory" concept for Java...

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On 08/22/2014 12:49 PM, Andreas Leitgeb wrote:
> I'm fully aware, that the concept of a mutable "current directory"
> for the whole VM does not work at all well with threads, and thus
> there is of course no such thing like "System.chDir(...)" in Java.
>
> Instead, I'd like to use a mutable Wrapper for java.nio.file.Path
> and whereever I need to access a file, I'd call a method on the
> wrapper and that would check, if the file's path is a relative
> or an absolute one, and eventually join it with the wrapped Path
> object. The wrapper itself then could offer something like a chDir()
> method to replace its wrapped Path by a target Path after following
> a series of ".."(for stepping up to the Parent-dir), or subfolders.
>
> e.g.: the wrapped Path of curDir originally points to "/tmp", then...
>   - curDir.chDir("foo") would go to "/tmp/foo", then
>   - curDir.chDir("../bar") would go to "/tmp/bar", then
>   - curDir.chDir("/foo") would go to "/foo"
> Whether it would check the file system about each of these
> paths, and whether it would resolve symlinks or just use them
> verbatim, is not among the things I care for at this point.
>
> With that, the concept of "current directory" would be tied to
> a particular "curDir" object, and the user would be responsible
> to either keep it to a single thread, or at least care about
> proper synchronisation across threads (as with all mutable objects).

A chroot() method might add complexity.

> I had a look at the classes/interfaces in java.(n)io, but couldn't
> find such a class. Is it not there, or did I just miss it?
>
> While it wouldn't be too hard to implement it for a particular
> platform, getting it right for different platforms (maybe even
> platforms where absolute/relative paths follow different patterns)
> would be tricky enough, that I'd rather use a library classes (if
> one exists), than roll my own.
>
> PS: Java 7 here
>

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A "current directory" concept for Java... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-22 16:49 +0000
  Re: A "current directory" concept for Java... Jeff Higgins <jeff@invalid.invalid> - 2014-08-22 14:50 -0400
  Re: A "current directory" concept for Java... Jeff Higgins <jeff@invalid.invalid> - 2014-08-22 15:10 -0400
  Re: A "current directory" concept for Java... Martin Gregorie <martin@address-in-sig.invalid> - 2014-08-22 19:26 +0000
    Re: A "current directory" concept for Java... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-22 23:38 +0000
      Re: A "current directory" concept for Java... Martin Gregorie <martin@address-in-sig.invalid> - 2014-08-23 14:24 +0000
        Re: A "current directory" concept for Java... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-23 16:31 +0000
          Re: A "current directory" concept for Java... Martin Gregorie <martin@address-in-sig.invalid> - 2014-08-23 19:34 +0000
            Re: A "current directory" concept for Java... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-24 08:42 +0000
              Re: A "current directory" concept for Java... Martin Gregorie <martin@address-in-sig.invalid> - 2014-08-24 10:37 +0000
                Re: A "current directory" concept for Java... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-24 13:41 +0000
                Re: A "current directory" concept for Java... Martin Gregorie <martin@address-in-sig.invalid> - 2014-08-24 18:33 +0000
                Re: A "current directory" concept for Java... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-24 22:33 +0000
                Re: A "current directory" concept for Java... Martin Gregorie <martin@address-in-sig.invalid> - 2014-08-25 00:14 +0000
  Re: A "current directory" concept for Java... Jeff Higgins <jeff@invalid.invalid> - 2014-08-22 19:45 -0400
    Re: A "current directory" concept for Java... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-23 15:32 +0000
      Re: A "current directory" concept for Java... Jeff Higgins <jeff@invalid.invalid> - 2014-08-23 12:49 -0400
      Re: A "current directory" concept for Java... Jeff Higgins <jeff@invalid.invalid> - 2014-08-23 17:40 -0400
  Re: A "current directory" concept for Java... Jan Burse <janburse@fastmail.fm> - 2014-08-23 10:31 +0200
    With new Path (Re: A "current directory" concept for Java...) Jan Burse <janburse@fastmail.fm> - 2014-08-23 10:48 +0200
      Re: With new Path (Re: A "current directory" concept for Java...) Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-23 14:38 +0000
  Re: A "current directory" concept for Java... Roedy Green <see_website@mindprod.com.invalid> - 2014-08-23 05:31 -0700

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