Re: [Help-tar] Trouble with tar -xzf when using --files-from=-

[Reuti]

> Am 22.10.2015 um 16:37 schrieb Reuti <address@hidden>:
> 
> Tony:
> 
>> Am 21.10.2015 um 14:30 schrieb Tony Olekshy <address@hidden>:
>> 
>> Tony Olekshy wrote, on 2015-10-20 at 19:20 MDT:
>>> 
>>> Hello.
>>> 
>>> I'm having trouble understanding why I can't pipe the output of a
>>> tar -tzf a.tgz ... through to a tar -xzf a.tgz --files=from=- ...
>>> without producing what appear to be spurious messages. In practice
>>> I want to place a filter in that pipeline to select just what to
>>> extract, but the following script simplifies that out to just show
>>> the problem I'm encountering.
>> 
>> Reuti wrote, on 2015-10-21 at 04:32 MDT:
>>> 
>>> Accessing "." in the archive will move its pointer already to
>>> the end:
>>> 
>>> $ echo . | tar tf archive.tgz --files-from=-
>>> ./
>>> ./foo/
>>> ./foo/bar
>> 
>> Reuti wrote, on 2015-10-21 at 05:10 MDT:
>>> 
>>> Ah, although I missed the --no-recursion at the first glance: its
>>> position is important. It must appear before the --files-from=- in
>>> your case.
>> 
>> Perfect, that did it. The attached script with the --no-recursion
>> placed before the --files-from=- does exactly what I'm looking for,
>> and I've tested it with a filter between the tar -t and the tar -x
>> (a simple head -2 works for this testing), and it all works well.
>> 
>> Thank you very much for you assistance with this matter, Reuti. Now
>> I understand the difference between tar's globally scoped options &
>> those that only apply to succeeding arguments.
> 
> A short question: did you test your script also with 1.28? While it is 
> working in 1.26 now, I get the impression that in 1.28:
> 
> 1) --files-from must be an exact match, hence --no-recursion has no meaning 
> for it now
> 
> 2) Due to 1), plain directories can't be extracted with --files-from any 
> longer, only on the command line:

Aha, while you can extract "./" or "./foo/" on the command line, only a plain 
"." or "./foo" is allowed in the --files-from=. Nevertheless will the --list 
append the / for a directory in the output again.

-- Reuti


> $ cat lister
> ./foo/
> $ local/tar-1.28/bin/tar --list --file=test/archive.tgz --files-from=lister
> local/tar-1.28/bin/tar: ./foo/: Not found in archive
> local/tar-1.28/bin/tar: Exiting with failure status due to previous errors
> $ local/tar-1.28/bin/tar --list --file=test/archive.tgz ./foo/
> ./foo/
> ./foo/bar
> $ local/tar-1.28/bin/tar --list --file=test/archive.tgz --no-recursion ./foo/
> ./foo/
> 
> Can you confirm this?
> 
> -- Reuti