Re: [Lzip-bug] Tarlz 0.4: Use of 'ustar' format instead of 'posix'; question about future of Tarlz utility

[Timothy Beryl Grahek]

Hi Antonio,

> It is both possible and desirable. The 'posix' format is an extension 
> on top of the 'ustar' format, so I plan to make tarlz use a "limited 
> posix format"; 'ustar' where posible and 'posix' only on the files 
> requiring it for any reason (long name, large size). This removes all 
> limitations while remaining as compatible and simple as possible. 

That sounds excellent and would greatly increase Tarlz's usability.

> > Would you be interested in expanding the features of Tarlz to make it a
> > more feature rich utility?
>
> Sure. Suggestions are welcome. :-)

Thanks! Four features that would make Tarlz even more useful are these:

 * Expanding the operations of Tarlz to include --delete and -A
   (concatenate) would be helpful to me, since those are the two
   additional operations I tend to use in tar programs.
 * For the '-c' and '-x' operations, if it could report %
   (de)compression progress per file in an archive based on the '-vv'
   option, that would be helpful.
 * If it could report an average % compression and other statistics
   summary based on, say, a '-s' option for the '-t', '-c', and '-x'
   operations, that would be helpful. This could be similar to what
   Lzip reports after successful compression and decompression of
   files, except it would describe an archive rather than an individual
   file.
 * If the '-t' operation could display the compression saved % and
   ratio % per file in an archive by specifying a '-v' or '-vv' option,
   that would be helpful. It may make sense if the '-c' and '-x'
   operations could display this, too, when specifying the '-vv' option
   after successfully (de)compressing files in an archive.

But by far the most valuable change to Tarlz, in my humble opinion, is 
implementing that "limited posix format" that you mentioned. :-)

> Here you can find the specification of the 'ustar' and 'posix' (pax) 
> formats:
> http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html

I will certainly take a look at that link, thank you.

> Glad to know that tarlz is already useful to someone. :-)
Yes, Tarlz has turned out to be extremely useful. :-) In practice, not 
having a multi-member format for archives larger than, say, 6 GB is 
quite inconvenient when you want to extract individual folders or files 
from an archive and you don't have a fast processor or SSD, neither of 
which do I have. I have an Intel Core 2 Duo E8400 with an HDD, so I 
think my machine may be a good test subject, haha.

Best regards,

Timothy Beryl Grahek