Lasse, The maintainer is happy that no backwardly-incompatible changes will be made, but is still a bit concerned that older versions of xz utils may not work with newer versions of the xz format. Given an xz file, is there a way to determine which version of the xz format it uses. Something like:
xz-get-version foo.xz --> foo.xz uses XZ format version 1.0.4 Thanks. Regards, Tom -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Lasse Collin Sent: Sunday, November 06, 2011 9:11 AM To: [email protected] Subject: Re: [xz-devel] Is the xz format stable? On 2011-11-06 Tom Trauth wrote: > I am trying to submit a patch to an open source project to add xz > support to it, but before accepting it the maintainer wants me to get > a promise from the xz developers that the xz format is now stable and > will have no backwardly incompatible modifications in the future. It is stable in sense that new tools will always be able to decompress old .xz files that have been created with a stable release of XZ Utils. It is possible and even somewhat likely that new features will be added in the future which old programs won't support. Compare to the .zip format. It has got support for new compression methods and other features over the years, including LZMA support. When maximum portability is needed, people stick to the Deflate algorithm which all non-ancient .zip implementations support. > But he > apparently had a bad experience with the lzma format changing its > format several times and therefore does not trust xz. The old .lzma format hasn't changed since it was introduced in LZMA SDK and also used by LZMA Utils. There were development versions of the .xz format that used also the .lzma suffix, but no one has claimed that those alpha versions would be stable. If someone has thought the development versions were stable, it has been a major misunderstanding. -- Lasse Collin | IRC: Larhzu @ IRCnet & Freenode
