Random collection of amazing stuff

The most cool thing that I noticed today ever is that Google Maps now allows you to add custom waypoints by dragging-and-dropping the route line onto a given road. This is great! I'm going to a charity biker raffle thing in Pensford next weekend, and Google's usual recommendation is that I stay on the M4 to Bristol, and drive through Bristol towards Shepton Mallet. This is, frankly, ludicrous. It's much more sensible to go through Bath and attack the A37 from the South, and now I can let Google know that.

Trusted JDS is über-cool. Not so much the actual functionality, which is somewhere between being pointy-haired enterprisey nonsense and NSA-derived "we require this feature, we can't tell you why, or what it is, or how it should work, but implement it because I'm authorised to shoot you and move in with your wife" fun. But implementing Mandatory Access Control in a GUI, and having it work, and make sense, is one hell of an achievement. Seven hells, in the case of Trusted Openlook, of which none are achievement. My favourite part of TJDS is that the access controls are checked by pasteboard actions, so trying to paste Top Secret text into an Unrestricted e-mail becomes a no-no.

There does exist Mac MAC (sorry, I've also written "do DO" this week) support, in the form of SEDarwin, but (as with SELinux) most of the time spent in designing policies for SEDarwin actually boils down to opening up enough permissions to stop from breaking stuff - and that stuff mainly breaks because the applications (or even the libraries on which those applications are based) don't expect to not be allowed to, for instance, talk to the pasteboard server. In fact, I'm going to save this post as a draft, then kill pbs and see what happens.

Hmmm... that isn't what I expected. I can actually still copy and paste text (probably uses a different pasteboard mechanism). pbs is a zombie, though. Killed an app by trying to copy an image out of it, too, and both of these symptoms would seem to fit with my assumption above; Cocoa just doesn't know what to do if the pasteboard server isn't available. If you started restricting access to it (and probably the DO name servers and distributed notification centres too) then you'd be in a right mess.

It's update o'clock

In other words, it's "Graham remembers that someone needs to write the interwebs, too" time. The main reason I haven't written in a while is that I'm enjoying the new job, so it's satiating my hacking desires. No hacking projects = nothing to talk about. I can't really talk about the work stuff, either; this is unfortunate because I did some really cool KVC-cheating in a prototype app I wrote, and it'd be a good article to describe that.

I've more or less dropped off the GNUstep radar recently. I still need to talk to the employers' legal eagles in order to update my FSF copyright assignment, and then find something to hack on. Currently I only have a Mac OS X machine so I'd probably switch to some app-level stuff. I have half a plan in my mind for a SOPE app, but despite reading all the documentation I still haven't worked out how to get started :-|. The code isn't too much of a problem, I've used WebObejcts before, but WebObjects has a 'hit this button to build and run your WebObjects code' button, and there's no description AFAICT for SOPE of what to put in the GNUmakefile to get built and running SOPE code, even whether you're supposed to provide your own main() or anything. Hmmm...I wonder if there's a sample project around...

Ich habe mein Handy verloren

Ooops. Left my mobile phone on holiday in Germany when I came back. This may explain why some people who were expecting to hear from me in Germany didn't...anyway, could anyone who thinks I ought to know their phone number please either leave a private comment on this livejournal entry (all comments are private by default on that post), or e-mail me? Thankyou! I promise to buy a filofax which I won't leave in foreign parts.

The new netiquette

It used to be that netiquette was all about TURNING OFF THE CAPS LOCK, making sure that the subject matched the content, that you didn't go off the wall if someone didn't reply to your e-mail in a few minutes, that sort of thing. In fact, this (RFC1855) sort of thing. But now there are different netiquette requirements, and no obvious guidelines, nor seemingly any common practices. Now I'm just the kind of person who thinks that some de facto ruleset would be useful, so that everyone knows what to expect from everyone else.

For instance, take social networking sites like LinkedIn or Facebook. How well do you know someone before you 'add' them as a friend? Once met at a conference, once read their blog, cohabited for two years? Do you talk to them first, to let them know who you are and that you're not a crazy stalker? If someone adds you, and you don't know who they are, do you accept or reject by default? Do you ask them who they are? If they claim to have met you at $conference or in $pub, do you accept that, ask for a photo, or what?

A bit late for that, isn't it?

Just won the above-linkied item on eBay: the Amiga SDK :-) I'm probably slightly late to make any money out of Amiga development, but I'm glad I finally get to tinker. Might have to crack open the AROS if I get sufficiently involved...

I could probably write a three-page rant about how great the Amiga was and how badly Commodore stuffed up. But of course, none of it would be new ;-).

Apple and Google sitting in a tree, f-i-g-h...erm...t-i-ng

This really came out of a throwaway comment I made on Daniel, but it seems popular to pick apart every last iota of Steveness from the WWDC keynote, and I'm nothing if not popular. So here we go.

What is WebClip? In fact, that's not really the question I want to be asking. We know what WebClip is; it's a technology which lets users see only the bits of web pages that those users want to see. The real question is what does that mean? Well, I know which bits of a web page I usually want to see; they're the bits which aren't adverts.

I'm going to go out on a bit of a limb, and guess that the way WebClip works (I'm not a WWDC bod so I don't have any more access to the new stuff than anyone else; in fact I haven't even downloaded the Safari 3 beta) is by observing which DOM elements are within the clipped region, and downloading only media relevant to those elements. If that's the case, then you can ignore the fact that the ads on the page don't get seen; they don't even get downloaded. Therefore if I'm reading, say, the Dilbert strip in a WebClip, I'm effectively getting free Dilbert, even more free than the free website because I'm not upping their ad impression count.

One thing I noticed about the various sites that Steve clipped is that as far as I can remember, none of them features 'Ads by Google'. It would be quite embarrassing for Apple's CEO to demonstrate how to reduce revenue for one of Apple's most prominent board members in a world-broadcast keynote talk. As over 99% of Google's revenue is from online ads, and Eric Schmidt (CEO of Google) is on the Apple board, that is exactly what Steve was showing us, though. There'll be a doughnut fight back at Infinite Loop over that, I expect.

Miniwindows

Maybe it's just me who gets annoyed by teeny-tiny miniaturised views which are completely illegible. Even so, I've just uploaded an article I wrote on Miniwindows which can be used in any OpenStep implementation such as Cocoa or GNUstep. It's based on the Hillegass TypingTutor example, but doesn't really use any code from that and isn't (I hope) otherwise reliant on that context, so it should be possible to see what's going on even if you haven't read Hillegass. Which you should ;-)

Moving on

There has been some cat-escaping-bagness, which is mainly my fault, but now that it's all official I'm going to 'announce' it myself: I've got a new job! From the end of July, I'll be working at Sophos as Senior Software Engineer, Mac (the post is still up at the linky in the title, for the moment).

This looks like being an exciting time - I've been enjoying the ObjC hacking I do with Brainstorm and this will be an opportunity to do even more of that, and the move from services to user-installed apps will bring its own changes and new experiences.

Erm, that really is all for now. More info as it becomes available, and all that.

A bit of backup script

Good news - there's a handy tool in OS X called wait4path which can help when writing timed scripts to backup to removable media.

Bad news - it [at least in Tiger....] works slightly esoterically - if a path is already present, it will still wait for another mount kevent before exiting. It should therefore be used in a script like this:

#!/bin/sh

if [ ! -d /Volumes/Backups ]; then
echo "waiting for backup volume..."
/bin/wait4path /Volumes/Backups
fi

# do some backups

Note, however, that if you do this in a crontab job it could potentially wait for a very long time, so you should wrap all that with a /var/run style semaphore.

Official Google Mac Blog: Measuring performance of distributed notifications

Official Google Mac Blog: Measuring performance of distributed notifications on the performance of Google Update: "Just how expensive is it? How many notifications can you broadcast per second? As with all Google client products, we want to be good citizens and not bog down the client machine."

A noble sentiment, but dear Google, answer me this: just how many times per second is each app going to be checking for updates? When does this become an important factor, and not a question of premature optimisation? They decided to go for distributed notifications instead of distributed objects, which seems reasonable - not because of the overhead issues (in fact a DO is probably a lot cheaper, if written properly), but because of the kind of information they're trying to get through this IPC.

Bye bye data, hello...the same data

Of course it happens to everyone, and yesterday evening it happened to me...my home directory became inaccessible. What seems to have happened is that the filevault image containing my ~ became corrupted upon unmounting (though notably, I didn't do the 'recover space' thing the last time I logged out before the failure, so it should just have been a straightforward unmount). so the simplest recovery route was to delete the user, re-create it then recover my data from the backups. I don't keep backups of the Library area so lost a few preference files, and of course have had to trawl around my email looking for licence keys and the like.

For the moment I've set up the replacement user without Filevault, and am using encrypted disk images for specific data I'd rather keep thus protected. This makes backups harder - I keep my backup drive unencrypted as it doesn't come out with me, so I now need to come up with a script to backup my home dir except for the encrypted images, mount the images and back up the content, then unmount them. This means that the backup will need to be manually triggered so that passwords don't have to be kept anywhere...or I write my own backup tool, which uses passwords stored in a keychain kept outside the target user account; and I need to make sure that keychain is also recoverable ;-).

A lot of my data was completely unaffected - work stuff is typically stored in subversion on their servers (as well as another local copy on my work laptop), my email is all on remote servers, my calendar is served by thaesofereode.info and so on. There are some improvements I could make - I could probably use an LDAP server and abxldap to remotify my contact list, and thaesofereode.info offers subversion hosting which I'm currently not making use of. But it happens that next Tuesday, I'll be talking about data security at the Oxford Mac Users Group, so I will expand on this tale in full and gory detail ;-). St. Cross College, Tuesday 8th May, 7:30 pm.

Update 20070503T1653Z+0000: actually, things look a little more serious than simply a trashed sparseimage:

mabinogi:~/Desktop leeg$ hdiutil attach OmniDazzle-1.0.1.dmg
load_hdi: timed out waiting for driver to load
load_hdi: timed out waiting for driver to load
load_hdi: timed out waiting for driver to load
load_hdi: timed out waiting for driver to load
load_hdi: timed out waiting for driver to load
[...]
2007-05-03 15:41:35.535 diskimages-helper[718] ERROR: unable to load disk image driver - 0xE00002C0/-536870208 - Device not configured.

Good news is that when that gets fixed, my old homedir will start working again. Bad news is: um, it looks fairly messed up to me :-(

All the more reason to like FOSDEM

So it seems that my half-attendance at FOSDEM paid off more than I could have hoped, as I won a year's subscription to GNU/Linux magazine. The publication is francophonic, so this will be a good chance to improve my command of la langue des grenouilles ;-).

Summer of code

GNUstep has been approved for this year's Google Summer of Code. The title link goes to the GNUstep wiki page outlining possible projects, but I'm sure that if a student had another idea you'd be welcome to talk about it on the gnustep-discuss mailing list, and probably get a mentor!

Mail::Box++

When most perl developers (I believe there still are one or two in existence) talk of the "cool one-liner" that they wrote, what they actually mean is that they grabbed a crapload of packages from CPAN, invoked a few use directives and then, finally, could write one line of their own code which happens to invoke a few hundred lines of someone else's code, which they have neither read nor tested.

Modulo testing, my short script (below) to convert mbox mailboxes to maildirs is exactly like that. While it has three lines of meat, these call upon the (from what I can tell, fantastic) Mail::Box module to do the heavy lifting. That package itself is less svelte, with 775 lines of perl. Which is the interface to a C bundle, which is (single-arch) 92k. But never mind, I still wrote a three-liner ;-)

#!/usr/bin/perl -w

use strict;

use Mail::Box::Manager;

@ARGV = ("~/mail", "~/Maildir") unless @ARGV;


# open the existing (mbox) folders
my $mgr = new Mail::Box::Manager;
my ($srcPath, $dstPath) = @ARGV;
# expand tildes and stuff
$srcPath = glob $srcPath;
$dstPath = glob $dstPath;

opendir MBOXDIR, $srcPath or die "couldn't open source path: $!";

foreach my $file (grep !/^\./, readdir MBOXDIR)
{
    my $mbox = $mgr->open(folder => "$srcPath/$file", 
     folderdir => "$srcPath");
    # open a maildir to store the result
    my $maildir = $mgr->open(folder =>  "$dstPath/$file",
        type => "Mail::Box::Maildir",
        access => 'rw',
         folderdir => "$dstPath",
         create => 1);

    $mgr->copyMessage($maildir, $mbox->messages);
}

FOSDEM / GNUstep photos

Just came in on #gnustep. Many photos of the GNUstep booth, dev room and of course the famous GNUstep dinner.

Apres ca, le FOSDEM

It appears that I'm sat in Terminal B of L'Aeroporte Nationale de Bruxelles, waiting for my flight to board. While there are wirelesses around, the ones to which I can connect seem not to be offering much in the way of DHCP so this update will come in later than it was written (which was at 13:35), as I will probably post it while I'm on the bus between Heathrow and Oxford. [Update: actually not until I got home]

Irrelevancies such as that aside, I had a great FOSDEM! In fact, a great half-FOSDEM, as I did my tourism today. I met a load of people (of which more below), went to some inspiring talks and discussed many exciting and interesting projects (in multiple languages - I spoke to one person in English, Dutch and French sometimes in the same sentence). It was a good exercise to see who wasn't present as much as who was - for instance RedHat didn't have an official presence although the Fedora Project had a booth (next to the CentOS one ;-), similarly Novell (one of the big sponsors) was absent but the OpenSUSE project had Yet Another Small Table. Sun were conspicuously present in that the OpenSolaris and OpenJDK table was being manned seemingly by Sun's salespeople rather than user group members...although maybe that's just my interpretation.

The overriding feeling I got was that the conference was running on l'espirit d'anarchie and that the resulting adrenaline and enthusiasm drove the conference on. The keynote speeches were really the only regimented aspect of FOSDEM - a necessity given the size of the auditorium and that was packed to the rafters with FLOSSers. I didn't go to the final keynote on open-sourcing Java as I was manning the GNUstep booth, but learned a lot on software patents and Free Software and Jim Gettys' description of the technical challenges in creating OLPC was very insightful.

So, GNUstep. GNUstep, GNUstep, Etoile [I'll add the accents in in a later update...this keyboard doesn't have dead keys :-(]. For a start it was great to meet all the other GNUsteppers, and have some good discussions and debates (as well as some good moule frites and Kwak beer). For anyone who doubts that GNUstep is still alive, the dev room at FOSDEM is one place to allay such suspicions with many developers, designers, users and supporters presenting their ideas to each other, asking each other questions and generally contributing to the GNUstep camaraderie. Even an improptu troll by Miguel de Icaza at the GNUstep booth wasn't enough to make us all throw Project Center away and buy a book on C# ;-). Presentations on GNUstep-make v2 (which I've described here before...), the Cairo graphics back-end (which I don't think Fred Kiefer was expecting to present, but made a very fine job of it anyway) and third-party use of GNUstep were all very useful and well-received...I expect today's presentations were too but I didn't get to go to them :-(. [Instead, I was significantly underwhelmed by the sight of the Mannekin Pis.]

Fairly cool update to GNUstep

GNUstep-make now supports arbitrary(-ish) filesystem layouts. While the default is still the /usr/GNUstep layout with the various domains, one of the bundled alternatives is to put everything in FHS-compliant locations. Once that hits a release (which I believe will be called gnustep-make 2.0), that should make newbie users and distributors much more comfortable with GNUstep. I also provided a NeXT-ish layout which doesn't clone the NeXT directory hierarchy, but rather mimics it sensitively.

My work laptop just earned itself a reinstall (I'd been uncomfortable with CentOS for a while, but the facts that hotplug isn't configured properly and every time I 'yum update' I have to fix a handful of drivers drove me over the edge), so when I re-create my GNUstep installation I'll do it with the new-style make. I'm currently wavering on the side of installing Midnight BSD, but I might wimp out and dual-boot Ubuntu ;-)

Where are we going?

Recently, XML seems to have been playing an important role for me...I've been working with various XML-RPC frameworks, reviewing a book on XHTML (actually, a book on HTML 4 which occasionally reminds you to close elements) and also dealing with DocBook. For some reason, this means when I read something like Ten predictions for XML in 2007 I feel like I'm in a position to comment. Don't worry, I don't want to cover all ten points...

If I had to choose one big story for next year, it would be the Atom Publishing Protocol (APP). [...] APP is the first major protocol to be based on Representational State Transfer (REST), the architecture of the Web. Most systems to date have only used a subset of HTTP, usually GET and POST but not PUT or DELETE. Many systems like SOAP and Web-based Distributed Authoring and Versioning (WebDAV) have been actively contradictory to the design of HTTP. APP, by contrast, is working with HTTP rather than against it.

Well, this suits me...a complete bi-directional implementation of HTTP would certainly be pleasant to use. But the point is that you already can do bi-directional transactions with these ugly hack interfaces, which importantly are already in use. This isn't like moving from rcp to HTTP to do your file uploads, this is like moving from HTTP to a version of HTTP which IE doesn't recognise for doing your content publication. WebDAV might be ugly but it already allows people to run their Subversion or calendar (yes, I know...) servers over "the web". APP is good but the activation energy may be too high.

2007 is the make-or-break year for the Semantic Web.

s/make-or-//, I believe. I've talked to two people who considered themselves important in the world of the semantic web, and have attended a talk by Sir Tim on the subject. I still have yet to see anything beyond so-called blue skies proposals and views on how much better the web will be once everyone embraces semantics, which none of them appeared to have done. At least, there's nothing yet which has convinced me that Semantic Web is some kind of killer app, and that what it can do can't already be done with a bit of XML/XSLT and some good schemas. Maybe that's the point, that traditional web will just slide into Semanticism by dint of XQuery, XProc and the rest of the X* bunch. I don't think so.

2007 will be the first year in which almost every significant browser fully supports XSLT 1.0 [...] I predict that this will render many of the debates about HTML 5 and XHTML 2 moot. Sites will publish content in whatever XML vocabulary they like, and provide stylesheets that convert it to HTML for browser display.

Yup, this couldn't come too soon. I sorely hope that HTML 5 will be still-born; redundant as soon as it becomes available. I also hope that document-generating frameworks will become better at generating valid markup in the future (which is at least easier to do with XML than SGML)...of course if browsers really do make a good job of supporting XSLT then they won't really be able to generate invalid markup as they'll be doing it in their own format.

Apple will release Safari 3 along with Leopard. Although it will focus mostly on Apple proprietary extensions, Safari 3 will add support for Scalable Vector Graphics (SVG) for the first time.

That's not much of a prediction, unless predicting things means reading the WebKit changelog. What would be good is for a couple of the more popular also-ran browsers to support MathML (I think Firefox already does in some fashion, WebKit is at the "we're thinking about it" stage, and I really don't know about any others) so that it has a chance of being adopted. I speak here as an ex-physicist who was annoyed at seeing academics putting DVI or PostScript files on the web, or (and this is just as bad if not worse) HTML with graphics of the equations. If LaTeX could be transformed into HTML+MathML and published on the web then we'd be somewhere approaching the original goal of the Nexus.

FAQ update

Just a warning about @defs not necessarily being a good idea, some code from Mike Ash to add polish to the forwarding example and...um...I'm sure I added something else. Oh yes, the fact that _cmd is the name of the SEL argument in method definitions.

I'm quite inclined to refactor the FAQ (because the source is basically the XHTML), as something like a DocBook FAQ Article, which might explain any (further) hiatus in updates. I haven't started working on this yet but it seems more attractive, as I look at the horrendous car crash of formatting produced by a combination of different text editors I've been using.

Why Java is so damned lame, part exp(I*M_PI)

Gah. Back when I used to work for Oxford University, I had to do the occasional bit of Java programming for a WebObjects app. Being quite a bit more familiar with ObjC than with Java, I always found this a bit of a headache...partly the way Java Foundation is semi-bridged with the "real" Java API meant I was constantly referring to my Tiger book (Java in a Nutshell, not Mac OS X Tiger), and partly because ironically Java required a lot more mystical casting voodoo than ObjC...seriously, if I never see the phrase Session session=(Session)session() again, I'll be a happy man.

Today's "gah, why can't Java be as easy as ObjC" moment came courtesy of an algorithmic problem I was attacking at TopCoder, just for the hell of it. Problem is, to get to their problem definitions you have to use their applet thingy, and while I'm there I decided that I may as well type the code into their thingy after all Java's not that bad is it? [They also accept VB, C# and C++ but my recollection of the C++ class syntax is slim and my knowledge of the STL is slimmer...I do know enough to try and avoid it though] So I think their problem definitions are proprietary, but suffice to say I wanted the ability to compare two strings, returning equal if the strings could be made the same by popping any arbitrary number of characters off the front and shifting them onto the back (i.e. treating them like rings of characters).

Well, that's simple isn't it? In ObjC I'd subclass NSString, override isEqual: and Robert is your parent's sibling. I even know how to do that in Java:

class CircularString extends String {
  public boolean equals(Object otherObj) {
    //....
  }
}

Only...no. You're not allowed to do that, because for some unfathomable reason Gosling and the boys at Oak decided to inflict on us another voodoo keyword...final. This seems to have one purpose in existence: to stop me from subclassing the String class. In the words of Points of View, Why oh why oh why oh why?