[Lzip-bug] Tarlz 0.15 released

[Antonio Diaz Diaz]

I am pleased to announce the release of tarlz 0.15.

Tarlz is a massively parallel (multi-threaded) combined implementation 
of the tar archiver and the lzip compressor. Tarlz creates archives in a 
simplified posix pax format compressed with lzip, keeping the alignment 
between tar members and lzip members. This method adds an indexed lzip 
layer on top of the tar archive, making it possible to decode the 
archive safely in parallel. The resulting multimember tar.lz archive is 
fully backward compatible with standard tar tools like GNU tar, which 
treat it like any other tar.lz archive. Tarlz can append files to the 
end of such compressed archives.

Tarlz can create tar archives with five levels of compression 
granularity; per file, per block (default), per directory, appendable 
solid, and solid. It can also create uncompressed tar archives.

Of course, compressing each file (or each directory) individually can't 
achieve a compression ratio as high as compressing solidly the whole tar 
archive, but it has the following advantages:

   * The resulting multimember tar.lz archive can be decompressed in
     parallel, multiplying the decompression speed.

   * New members can be appended to the archive (by removing the EOF
     member), and unwanted members can be deleted from the archive.
     Just like an uncompressed tar archive.

   * It is a safe posix-style backup format. In case of corruption,
     tarlz can extract all the undamaged members from the tar.lz
     archive, skipping over the damaged members, just like the standard
     (uncompressed) tar. Moreover, the option '--keep-damaged' can be
     used to recover as much data as possible from each damaged member,
     and lziprecover can be used to recover some of the damaged members.

   * A multimember tar.lz archive is usually smaller than the
     corresponding solidly compressed tar.gz archive, except when
     individually compressing files smaller than about 32 KiB.

Note that the posix pax format has a serious flaw. The metadata stored 
in pax extended records are not protected by any kind of check sequence. 
Because of this, tarlz protects the extended records with a CRC in a way 
compatible with standard tar tools.

The homepage is at http://www.nongnu.org/lzip/tarlz.html

An online manual for tarlz can be found at 
http://www.nongnu.org/lzip/manual/tarlz_manual.html

The sources can be downloaded from
http://download.savannah.gnu.org/releases/lzip/tarlz/

The sha256sum is:
f2892fd75950f55b8fbb87a40bb049ae312a93785dee1ffb4b5f6e397538ae2c 
tarlz-0.15.tar.lz


Changes in version 0.15:

  * The new option '--delete', which deletes files and directories from 
an archive in place, has been added. It currently can delete only from 
uncompressed archives and from archives with individually compressed 
files ('--no-solid' archives).

  * Multi-threaded listing of compressed archives with format 
violations (for example, an extended header without the corresponding 
ustar header) has been fixed.


Please send bug reports and suggestions to address@hidden


Regards,
Antonio Diaz, tarlz author and maintainer.
Self-determination is a right, not a crime. Free Catalan political 
prisoners.
--
If you care about long-term archiving, please help me replace xz with 
lzip. See http://www.nongnu.org/lzip/lzip_benchmark.html#xz1
http://www.nongnu.org/lzip/manual/lzip_manual.html#Quality-assurance and
http://www.nongnu.org/lzip/xz_inadequate.html Thanks.