Re: [Bug-tar] Feature request: counterpiece to option sequence "--null" "--files-from=..." for option "--list"

[Sergey Poznyakoff]

Helmut Waitzmann <address@hidden> wrote:

> >I'd rather extend the semantics of --null to cover archive listing as
> >well. It won't break the existing functionality in any way.
> 
> It would make it impossible to make tar list some archive member names in
> a human readable form, when the archive member names to be listed are fed
> into tar with the "--files-from" and "--null" options, as it would result
> in a NUL separated member list with control characters not quoted.

Hmm, yes, you are right.
 
> Also it is not clear to me, what should be done, if the "--verbose" option is
> supplied, too:

In my opinion --list-null and --verbose should be mutually
exclusive. The only reason to use --list-null would be to pipe
the output to the other program, and I can hardly see any reason
to output any extra information in this case.

> e.g. "--list=type,perm,ownername,groupname,size,mtime,name", which could
> specify the order of the selected fields, too.  What do you think?

Wow, that's a nice idea. 
 
> >Well, but how will it differ from running:
> >
> > tar -f archive.tar --list | \
> >   xargs -- process the archive member names as you like
> 
> With GNU xargs version 4.1.7, archive member names with spaces or control
> characters will fail, as xargs doesn't understand the gnu tar quoting
> style and splits lines with spaces in it

Instead of --list-null we'd rather need an option that would produce
file names compatible with what other GNU utilities expect, or, better yet,
tar should output such names in its listings by default. 

Regards,
Sergey