[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Where is data stored when Synaptic scans DVDs?



On Sun 19 Mar 2017 at 23:25:47 -0500, David Wright wrote:

> On Sun 19 Mar 2017 at 08:50:55 (-0500), Richard Owlett wrote:
> > On 03/19/2017 08:08 AM, David Wright wrote:
> > >[snip ;]
> > >
> > >How's the other research coming along?
> > >Did you see if there were files whose timestamps change?
> > >Did you see whether you can find the files which are apparently
> > >indexed in /var/lib/apt/cdroms.list?
> > >And if/when you find them, what are you going to use them for,
> > >in view of your new philosophy of working from the DVDs anyway?
> > 
> > It's not new. People just assumed that I would do things a certain
> > way because that would be the way they would do it.
> > I put effort into asking narrowly focused questions.
> 
> And I put effort into answering it as best I could.
> The first answer to the thread may well be correct, but
> you don't appear to have looked to see if it was correct.

The question asked is clear enough. The responses are muddy. I do not
think there is an agenda [1] here.

 > ...where is the data about contents of each DVD stored?

> I suggested /var/lib as another possibility, partly because
> I think it would be easier to eliminate. All the files in
> my /var/lib/apt are plain text, so it would be hard to hide
> the information from scanned CDs.

It isn't hidden.

> OTOH /var/cache/apt contains a couple of .bin files which
> have package names in them. Not having CDs to scan, I can't
> test the file timestamp idea. If they changed, it would
> suggest Jonathan was correct, but be trickier to prove.
> Hence checking, and possibly eliminating, /var/lib.
> Also there's the point that those .bin files may contain more
> than just some CD indexes, so sharing them between different
> systems would be high-risk.

I dug out my trusty set of Slink CDs [2] and popped CD1 into the cdrom
drive.

  root@gnome-stable:~# apt-cdrom ident
  Using CD-ROM mount point /media/cdrom/
  Mounting CD-ROM...
  Identifying... [312b07c10c39c9ce1e89be115088d562-2]
  Stored label: Debian GNU/Linux slink (2.1) 1/4 main binary-i386 section 1 SAM19990617
  Unmounting CD-ROM...

  root@gnome-stable:~# apt-cdrom add
  Using CD-ROM mount point /media/cdrom/
  Unmounting CD-ROM...
  Waiting for disc...
  Please insert a Disc in the drive and press enter
  Mounting CD-ROM...
  Identifying... [312b07c10c39c9ce1e89be115088d562-2]
  Scanning disc for index files...
  Found 4 package indexes, 0 source indexes, 0 translation indexes and 0 signatures
  This disc is called:
  'Debian GNU/Linux slink (2.1) 1/4 main binary-i386 section 1 SAM19990617'
  Reading Package Indexes... Done
  Writing new source list
  Source list entries for this disc are:
  deb cdrom:[Debian GNU/Linux slink (2.1) 1/4 main binary-i386 section 1 SAM19990617]/ slink contrib main non-US non-free
  Unmounting CD-ROM...
  Repeat this process for the rest of the CDs in your set.

A portion of the output:

  root@gnome-stable:~# ls -l /var/lib/apt/lists
  -rw-r--r-- 1 root root   873670 Mar 20 22:30 Debian%20GNU_Linux%20slink%20(2.1)%201_4%20main%20binary-i386%20section%201%20SAM19990617_dists_slink_main_binary-i386_Packages

There we are - a complete answer to the question and a completely
satisfied customer. :)

-- 
Brian

[1] I've given up on "agenda"; but not on "data". The World will
eventually see the error of its ways.

[2] I wonder whether Steve McIntyre still uses green ink to label
    his CDs.


Reply to: