GNU bug report logs - #42620
hard link improvement for gzip (wishlist item)

Previous Next

To reply to this bug, email your comments to 42620 AT debbugs.gnu.org.

Toggle the display of automated, internal messages from the tracker.

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Harald Dunkel <harald.dunkel <at> aixigo.com>
To: bug-gzip <at> gnu.org
Subject: hard link improvement for gzip (wishlist item)
Date: Thu, 30 Jul 2020 10:19:34 +0200

Hi folks,

this could be improved:

	% ls -l >x; ln -f x y; gzip x y
	gzip: x has 1 other link  -- unchanged
	gzip: y has 1 other link  -- unchanged

Regards
Harri

Message #8 received at 42620 <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Harald Dunkel <harald.dunkel <at> aixigo.com>, 42620 <at> debbugs.gnu.org
Subject: Re: bug#42620: hard link improvement for gzip (wishlist item)
Date: Thu, 30 Jul 2020 09:48:35 -0700

On 7/30/20 1:19 AM, Harald Dunkel wrote:
> this could be improved:
> 
>      % ls -l >x; ln -f x y; gzip x y
>      gzip: x has 1 other link  -- unchanged
>      gzip: y has 1 other link  -- unchanged

What improvement do you suggest?

Message #11 received at 42620 <at> debbugs.gnu.org (full text, mbox):

From: Harald Dunkel <harald.dunkel <at> aixigo.com>
To: Paul Eggert <eggert <at> cs.ucla.edu>, 42620 <at> debbugs.gnu.org
Subject: Re: bug#42620: hard link improvement for gzip (wishlist item)
Date: Fri, 31 Jul 2020 08:26:05 +0200

Looking at a file with n references by hard links:

n=1 is the trivial case. No changes needed.

All involved directories are read-only: Another trivial case
to be ignored here.

For n>1:

I would suggest that the file is compressed and the directory
entries are adjusted accordingly, if the directories can be
written.

If some directories are read-only, then you end up with 2 files,
the new compressed file and the old original still referenced
in the read-only directories.



The workaround for compressing a file with several references
in the file system is *very* ugly, even if you know all paths
pointing to it. And the need for compressing such a file comes
up especially for large files, i.e. those files that are
efficient to compress, but not easy to copy. Rotated log files
with a size of a few GBytes, for example.

Its just a suggestion, of course. Keep on your good work


Harri

Message #14 received at 42620 <at> debbugs.gnu.org (full text, mbox):

From: Harald Dunkel <harald.dunkel <at> aixigo.com>
To: Paul Eggert <eggert <at> cs.ucla.edu>, 42620 <at> debbugs.gnu.org
Subject: Re: bug#42620: hard link improvement for gzip (wishlist item)
Date: Fri, 31 Jul 2020 08:44:38 +0200

On 2020-07-31 08:26, Harald Dunkel wrote:
> Looking at a file with n references by hard links:
> 
> n=1 is the trivial case. No changes needed.
> 
> All involved directories are read-only: Another trivial case
> to be ignored here.
> 
> For n>1:
> 
> I would suggest that the file is compressed and the directory
> entries are adjusted accordingly, if the directories can be
> written.
> 
PS: All paths to the file have to be given on the gzip command line,
of course. I don't expect gzip to search for all references.


Regards
Harri

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.