Groups > comp.lang.java.programmer > #20015

Re: A proposal to handle file encodings

From	Martin Gregorie <martin@address-in-sig.invalid>
Newsgroups	comp.lang.java.programmer
Subject	Re: A proposal to handle file encodings
Date	2012-11-29 02:22 +0000
Organization	UK Free Software Network
Message-ID	<k96gtp$eia$1@localhost.localdomain> (permalink)
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On Tue, 27 Nov 2012 19:51:37 +0100, Peter J. Holzer wrote:

> The problem is that this just doesn't fit into the Unix system call
> scheme. There is no "copy" system call. The kernel just sees that a
> process opens one file for reading and another file for writing. It
> cannot assume that this process wants to copy the metadata from the
> first to the second file.
>
Of course.

> Of course Linux could introduce such a system
> call, but then those umpteen utility programs and libraries would still
> have to be modified to use that new system call.
>
I can see two ways of handling it: 

(1) introduce a pair of systems calls to retrieve and store the metadata 
associated with a file, and, yes, programs would need modification, but 
the amount would be trivial because you'd be looking at one extra line of 
code per file involved in the metadata transfer.

(2) alternatively it may be possible to do the job by adding a mode or to 
to the file opening operations. If they were defaulted appropriately, 
many programs could silently copy the metadata along with the data and/or 
automagically apply the appropriate transforms, such as charset 
transforms, during the transfer.

Thinking about it a little more, (2) is definitely the best solution 
because it would be rather useful to be able to default the metadata 
applied to a new file with a similar mechanism to that used for the 
permission bits. This sort of thing would be much easier to manage it is 
was built in to the filing system.

-- 
martin@   | Martin Gregorie
gregorie. | Essex, UK
org       |

Thread

A proposal to handle file encodings Roedy Green <see_website@mindprod.com.invalid> - 2012-11-22 13:36 -0800
  Re: A proposal to handle file encodings Joerg Meier <joergmmeier@arcor.de> - 2012-11-22 23:36 +0100
  Re: A proposal to handle file encodings markspace <-@.> - 2012-11-22 17:20 -0800
  Re: A proposal to handle file encodings Arne Vajhøj <arne@vajhoej.dk> - 2012-11-22 20:25 -0500
    Re: A proposal to handle file encodings markspace <-@.> - 2012-11-22 19:47 -0800
      Re: A proposal to handle file encodings Roedy Green <see_website@mindprod.com.invalid> - 2012-11-22 21:28 -0800
        Re: A proposal to handle file encodings Martin Gregorie <martin@address-in-sig.invalid> - 2012-11-24 15:51 +0000
          Re: A proposal to handle file encodings "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-11-25 10:18 +0100
            Re: A proposal to handle file encodings Martin Gregorie <martin@address-in-sig.invalid> - 2012-11-25 18:05 +0000
              Re: A proposal to handle file encodings "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-11-27 19:51 +0100
                Re: A proposal to handle file encodings Martin Gregorie <martin@address-in-sig.invalid> - 2012-11-29 02:22 +0000
                Re: A proposal to handle file encodings "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-12-02 13:02 +0100
                Re: A proposal to handle file encodings Martin Gregorie <martin@address-in-sig.invalid> - 2012-12-02 19:36 +0000
                Re: A proposal to handle file encodings "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-12-02 23:52 +0100
                Re: A proposal to handle file encodings Martin Gregorie <martin@address-in-sig.invalid> - 2012-12-02 23:08 +0000
    Re: A proposal to handle file encodings Sven Köhler <remove-sven.koehler@gmail.com> - 2012-11-25 13:13 +0100
      Re: A proposal to handle file encodings Martin Gregorie <martin@address-in-sig.invalid> - 2012-11-25 18:07 +0000
  Re: A proposal to handle file encodings Jan Burse <janburse@fastmail.fm> - 2012-11-23 16:33 +0100
    Re: A proposal to handle file encodings Roedy Green <see_website@mindprod.com.invalid> - 2012-11-23 09:02 -0800
      Re: A proposal to handle file encodings Jan Burse <janburse@fastmail.fm> - 2012-11-23 19:21 +0100
        Re: A proposal to handle file encodings "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-11-24 00:11 +0100
          Re: A proposal to handle file encodings Jan Burse <janburse@fastmail.fm> - 2012-11-24 00:53 +0100
            Re: A proposal to handle file encodings "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-11-24 09:13 +0100
            Re: A proposal to handle file encodings Roedy Green <see_website@mindprod.com.invalid> - 2012-11-24 06:50 -0800
              Re: A proposal to handle file encodings "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-11-25 10:07 +0100
                Re: A proposal to handle file encodings Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-11-25 11:06 -0600
                Re: A proposal to handle file encodings "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-11-27 19:28 +0100
          Re: A proposal to handle file encodings Roedy Green <see_website@mindprod.com.invalid> - 2012-11-24 06:42 -0800
            Re: A proposal to handle file encodings "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-11-25 09:57 +0100
          Re: A proposal to handle file encodings Sven Köhler <remove-sven.koehler@gmail.com> - 2012-11-25 15:09 +0100
        Re: A proposal to handle file encodings Sven Köhler <remove-sven.koehler@gmail.com> - 2012-11-25 15:06 +0100
      Re: A proposal to handle file encodings Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-11-23 16:43 -0600
        Re: A proposal to handle file encodings Jan Burse <janburse@fastmail.fm> - 2012-11-24 01:02 +0100
      Re: A proposal to handle file encodings BGB <cr88192@hotmail.com> - 2012-11-25 14:36 -0600
        Re: A proposal to handle file encodings Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-11-25 16:51 -0600
          Re: A proposal to handle file encodings BGB <cr88192@hotmail.com> - 2012-11-25 17:54 -0600
          Re: A proposal to handle file encodings Jan Burse <janburse@fastmail.fm> - 2012-11-26 02:03 +0100
            Re: A proposal to handle file encodings Jan Burse <janburse@fastmail.fm> - 2012-11-26 02:20 +0100
              Re: A proposal to handle file encodings Martin Gregorie <martin@address-in-sig.invalid> - 2012-11-26 02:46 +0000

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