From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3e1162e60705250803r12e1f0b3xec5b88b6308da1ea@mail.gmail.com> Date: Fri, 25 May 2007 08:03:11 -0700 From: "David Leimbach" To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu> Subject: Re: [9fans] XML In-Reply-To: <08c9db492e45590f15b629b99626a10d@terzarima.net> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <8ccc8ba40705211037j6607cd8o4c805e43ac45a0b2@mail.gmail.com> <08c9db492e45590f15b629b99626a10d@terzarima.net> Topicbox-Message-UUID: 718785ec-ead2-11e9-9d60-3106f5b1d025 On 5/22/07, Charles Forsyth wrote: > > However, we're still experimenting with this and I think that just > > placing a "toc" file > > i think just using s-expressions would do the trick, and be much easier to read. > > To be completely honest, a bit of the history of xar was a joking conversation by some friends of mine who happened to work at apple at the time. "Everything's better with XML, even tar". "XAR!" which is kind of fun to yell came out of it. Sadly I've found it useful after all of that was said and done. It's really not too bad with the abominations that are extended attributes (let's treat files as directories shall we? And hide all the data in key value pairs... ), Finder Info on mac os x, resource forks, etc. It's been working Ok on FreeBSD, Linux and Mac OS X, each with their slightly different APIs for dealing with those little nuggets of joy. And it's been re-written a few times. (because DOM is a horrible waste of resources if you don't need it, SAX-like processing of the XML posed an interesting challenge) I did compression on the XML TOC myself to add more to the joke. I mean when you have a table of contents in XML that's > 800 MB, you gotta do something :-) Anyway, it was originally just fun to work on, and probably serves more as proof of how much XML sucks. However Apple's adopting it in Leopard, probably due to the use of XML. Had we used S-expressions, I don't think they'd have known what to do with it. One of the leaders of the RPM project actually did something at some point to try to use xar instead of cpio archives for a new RPM back-end. I'm not sure it got anywhere. There was also a packaging system that someone started called "xpkg". Sometimes jokes get out of hand I guess.