Re: [Quilt-dev] Another shell re-write of backup-files.

[Jean Delvare]

On Friday 18 March 2011 09:15:18 pm Kaz Kylheku wrote:
> On Fri, 18 Mar 2011 20:43:52 +0100, Jean Delvare <address@hidden>
> 
> wrote:
> > On Friday 18 March 2011 06:32:18 pm Kaz Kylheku wrote:
> >> Plus a few more fixes. It's behaving well for me now. I'm ready
> >> for stress-testing with big patch stacks.
> >
> > May I ask why you keep investing time in a task which I just told
> > you I have _already_ accomplished?
> 
> Simply because it's not good to leave something 93% done
> (compared to, say, 100% or 40%, which are both good exit points,
> or even 99%). :)
> 
> This may also have to do with schooling. Just because
> your classmate has done the homework assignment doesn't
> mean you don't have to. :)
> 
> Before I started, I looked in the mailing list
> and GIT, but I didn't find the new script, unfortunately.
> This is something I need right away.

I would have sent it already if I didn't spend time today answering your 
e-mails and reviewing your code :p

> I just took an extra few minutes to put in the link-breaking
>  ``noop''.
> 
> Breaking hard links is done easily using an in-place sed (sed -i):
> 
>   find "$opt_prefix" -type f -links +1 | xargs sed -i -s ''

Except that it doesn't do what you want. What the script must do when 
passed -L alone is to break links on _original_ files, not _backed up_ 
files.

I told you that the semantics of backup-files are not trivial.

> 
> I'm happy with the way it works now, so I can leave it alone!
> 
> Index: quilt-hack/backup-files
> ===================================================================
> --- quilt-hack.orig/backup-files
> +++ quilt-hack/backup-files
> @@ -16,9 +16,8 @@
>  #   pass-through mode).
>  # - Use tree-to-tree recursive cp to restore a backup (taking
> everything
>  #   in the backup, ignoring the file list).
> -# - We don't use hard linking when restoring files, because then we
> have
> -#   to break the hard links anyway (quilt issues a noop -L
>  operation). -# - To touch restored files, we can do a copy without
>  preserving timestamps.
> +# - To touch files after restoring, we can do a copy without
> preserving
> +#   timestamps, rather than hard linking.
>  # - Added files (i.e. backups of nonexistent files) are represented
>  as a
>  #   specially named file containing an explicit list, and not as
>  #   zero-length files. This eases the implementation, and lets us
>  back @@ -221,9 +220,9 @@ R )
>       fi
> 
>       if [ $opt_touch ] ; then
> -             cp -dR --preserve=mode,ownership "$opt_prefix"/. .
> +             cp -Rf --preserve=mode,ownership "$opt_prefix"/. .
>       else
> -             cp -a "$opt_prefix"/. .
> +             cp -lRf "$opt_prefix"/. .
>       fi
> 
>       find "$opt_prefix" -type f -size 0c \
> @@ -237,8 +236,15 @@ R )
>  D )
>       rm -rf "$opt_prefix"
>       ;;
> -'' )
> -  # noop
> +'' ) # noop
> +     if [ $opt_nolink ] ; then
> +             if [ -z $all_backup_files ] ; then
> +                     echo "Error: breaking individual links is not supported"
> +                     exit 1
> +             fi
> +
> +             find "$opt_prefix" . -type f -links +1 | xargs sed -i -s ''

I doubt you really wanted to run this on both "$opt_prefix" and .

Both are wrong anyway...

> +     fi
>       ;;
>  * )
>       # multiple operations were specified together, like -b and -r.
> 

-- 
Jean Delvare
Suse L3