Talk:Pax (command)

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This article omits a lot of important information and history. "pax" is the name given to the command-line utility mentioned here, but also a POSIX-standardized archive format. Somewhat confusingly, the archive format (and it's specification) came after the utility -- the original pax utility only supported the tar and cpio formats. Even more confusingly, the MirBSD pax utility mentioned in this article still doesn't support the pax archive format. — Preceding unsigned comment added by 82.6.177.154 (talk • contribs) 18:19, 18 April 2016 (UTC)Reply

• I was about to note similar omissions and errors in the history. This article as currently written implies that pax was created in 2001, which is quite wrong. In fact, it was in the POSIX-2 draft standard right from its original version in September 1991, which took it from the earlier 1003.1b draft. It had already made it into books on the subject by 1991. Jonathan de Boyne Pollard (talk) 21:18, 16 January 2018 (UTC)Reply

Article often is unclear as to whether it means pax (the POSIX-defined utility) or pax (old 4.4BSD implementation) and that's unfortunate. I might try to correct this but it'd really mean huge changes to the article. Hope that's OK. 73.56.195.48 (talk) 15:00, 5 September 2020 (UTC)Reply

The infobox says "The Windows NT pax command", which the article also covers POSIX commands. (I'm not fixing this myself, since I don't know the correct headline to be used for the infobox.)

There is GNU paxutils project. According to the project page, it was started by François Pinard in 1994 or earlier and he maintained the project until 1999. The project's stated objective is to merge cpio, tar and pax commands under one project, which makes sense given the overlap of supported formats by the three commands. The merger never materialized, and instead, tar command added support for pax archive format.

Links:

• paxutils, gnu.org
• paxutils, savannah.gnu.org
• paxutils.git, git.savannah.gnu.org - main committers Sergey Poznyakoff and Paul Eggert
• NEWS, git.savannah.gnu.org
• ChangeLog.CVS, git.savannah.gnu.org - earliest log from 2004-09-06
• paxutils, alpha.gnu.org - download of alpha release from 1999-06-11
• tar, gnu.org
• tar, savannah.gnu.org
• cpio, gnu.org
• cpio, savannah.gnu.org
• pinard/paxutils, github.com
• pinard/paxutils/.../ChangeLog, github.com - earliest log from 1994-06-30
• Wikidata:Q76186095: GNU paxutils

--Dan Polansky (talk) 13:10, 9 July 2022 (UTC)Reply

pkgs.org[1] shows that some Linux distributions have spax or heirloom pax packages available, and these would have support for pax archive format. Examples include Adélie 1.0: heirloom-pax-1.0-r1.apk, AlmaLinux 8: spax-1.5.3-13.el8.aarch64.rpm, Amazon Linux 2: spax-1.5.2-13.amzn2.0.1.x86_64.rpm, CentOS BaseOS aarch64: spax-1.5.3-13.el8.aarch64.rpm, etc.

Groups:

• https://pkgs.org/download/heirloom-pax
• https://pkgs.org/download/spax
• https://pkgs.org/download/pax - for contrast

Related bugs:

• https://bugzilla.redhat.com/show_bug.cgi?id=503860
• https://bugzilla.redhat.com/show_bug.cgi?id=965658

Related repository:

• https://github.com/mmatuska/star

I would like to double check that spax (Schily pax) really supports pax format, but don't know how. --Dan Polansky (talk) 15:51, 10 July 2022 (UTC)Reply

At least, README.pax from github.com/mmatuska/star claims support for pax format: "The following extensions from SVSv3 / POSIX.1-2001 are implemented: [...] - Support for the PSOX.1-2001 [sic] extended TAR header format called 'pax'. --Dan Polansky (talk) 17:36, 10 July 2022 (UTC)Reply

And here is star (Schily tar) SourceForge project: https://sourceforge.net/projects/s-tar/ and possibly related snapshots: https://sourceforge.net/projects/schilytools/files/ .

It seems spax is part of star; at least the downloadable source code archive of star has pax.c and spax.1. --Dan Polansky (talk) 17:04, 10 July 2022 (UTC)Reply

I found the following bugs reported relating to pax, all of which seem related to MirBSD pax:

• pax: pattern matching not posix compliant, and not documented either, from 2004, bugs.debian.org
• Unable to create files larger than 2GB, from 2006, in ubuntu, bugs.launchpad.net
• pax lack of support for "pax" format fails LSB, from 2009, in paxmirabilis, bugs.launchpad.net
• pax lack of support for "pax" format fails LSB, from 2009, bugzilla.redhat.com
• Depend on 'spax' package, from 2013, bugzilla.redhat.com
• No UNIX compatible pax implementation, from 2014, in lsb, bugs.launchpad.net
• pax: claims POSIX compliance but doesn't support pax format, from 2014, bugs.debian.org
• pax is not compliant with the latest version of POSIX yet, from 2014, in ubuntu, bugs.launchpad.net

MirBSD bugs are further indicated here:

• pax.1 in MirBSD/mircpio, github.com - which can be seen as HTML probably here - sections STANDARDS and BUGS

Problems with spax from star (Schily tar) can be assessed in part from here:

• s-tar-developers mailing list, sourceforge.net

--Dan Polansky (talk) 12:45, 11 July 2022 (UTC)Reply