I’ve taken to carrying around a RawWorkflow WhiBal card when I’ve been out and about practicing my photography, and had a few people ask me what it’s for and how it helps.

WhiBal_PK_Main-9632_480x320.shkl.jpg

One of the nice things about how we see is that our brains are adept at adjusting our perception of what we see according to the lighting conditions. If we know that something is white we perceive it to be white, and can generally ignore the actual lighting conditions. For example, if you put on a pair of tinted sunglasses for a few minutes everything appears to take on the tint of the glasses. And then your brain adjusts, and everything appears to be the normal colour again.

Cameras don’t do this.
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I ran in to Smylers’ Talking at Conferences: A Beginners’ Guide the other day. It’s a very useful distillation of things you should consider if you’re thinking of giving a talk at a technical conference, such as YAPC Europe 2007, where the talk was delivered.

One recommendation in particular struck me, in re ordering the material in a presentation effectively.

But there is one metric which can be applied to a talk safe in the knowledge that following it would have taken exactly the same preparation time: would the talk have been better had exactly the same content been presented but in the reverse order.

I’ll be keeping that in mind next time I have to present something.

TripIt

September 4, 2007

If you’re a frequent (or even semi-frequent) traveller then you may be interested in a website that I’ve been using for the past few months.

TripIt exists to make it easy to manage one or more travel itineraries, and to share those itineraries with other people (who can be passive viewers, or active collaborators).

Signing up is easy, requiring the minimum of personal information. Once you’ve registered and activated your account you can start adding to your trip itineraries. It is possible to do this the tedious, manual way, by typing in the details of you trip — flights, car hire, accommodation bookings, and so on.

TripIt, viewing an itinerary

However, TripIt has an ace up its sleeve.

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I note that British Airways e-receipt e-mails are probably going astray for a lot of people.

I’ve had to book a few flights with BA recently. Up until a couple of weeks ago their acknowledgment e-mails came through fine. And then I stopped receiving them. Taking the time to delve in to the mail logs yesterday I noticed this:

Aug 20 07:47:45 jc sm-mta[15347]: l7KElEmk015347: ruleset=check_mail,
  arg1=website +LHS=RHS@bounce.baplc.com,
  relay=ceba-mgw04.baplc.com [163.166.43.64],
  reject=553 5.1.8 website +LHS=RHS@bounce.baplc.com...
  Domain of sender address website+LHS=RHS@bounce.baplc.com does not exist

(I’ve redacted the left and right hand side of the actual e-mail address it was being sent to)

If that’s just so much gibberish to you, it says that BA are sending e-mails with a return path of …@bounce.baplc.com. Working through the logs shows that they’ve been doing this for some time.

But at some point in the last few weeks, someone at BA has removed the bounce.baplc.com entry from their DNS. So my, and countless other systems around the world, will begin rejecting messages.

This rejection is quite correct. Since bounce.baplc.com doesn’t exist, my system (and any other system with the same configuration) will have nowhere to send any bounces that might occur. And sending messages from domains that do not exist is also an exceedingly common spammer tactic.

I’ve used the “Report problems with our site” feature to report this to BA, but I don’t have high hopes of anyone listening.

It’s been a bit quiet around here for the last couple of months. A quick brain dump.

In February I left my job helping to run the mail systems at Citigroup, having sorted myself out with a contracting role doing software development in Perl (with some Autosys and Murex mangling on the side) for the nice people at Brevan Howard. Quite definitely some of the nicest people I’ve had the pleasure of working with in the financial industry. If you’re a London-based Perl developer looking for work and the opportunity for a contract with them comes up, jump at it.

Along the way I finally got around to sorting myself out with a Flickr account, and you can see my photos at http://www.flickr.com/photos/nikclayton/. Not something I’ve written much about, but that may change in the future.

Anyway, that proved to be temporary. No, they didn’t fire me. Instead, in two days time I jump on a plane bound for Zurich, to start working as a site reliability engineer for Google Switzerland.

I was over there a couple of weeks ago as part of a preview-cum-orientation trip, which coincided with the once-every-three-years Züri Fäscht (Zurich Festival), so I took the opportunity to snap a few shots of fireworks.

Züri Fäscht

Züri Fäscht

Züri Fäscht

Anyway, I hope to write more next week about the process, useful sites for people undergoing a similar move, and so on. That, and getting back to contributing to projects like Subversion — my free time has been practically non-existent for the past 4 months or so, and that’s something that I’ve let slip.

If you publish SPF records, send mail to Korean ISPs, and use SPF mechnisms other than ip4:, you may face a problem.

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M-x ecb-activate

February 27, 2007

I’m a long time (x)emacs user. I use vi for small day-to-day stuff (vi TODO, anyone?), but as far as possible I do any development work with emacs, and have done for the past 12 years.

So, a few days ago I was pleased to discover a new mode that I’d not previously known about.

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Following on from yesterday’s discussion of new features in Sendmail 8.14.0, today I’m writing about Sendmail’s GreetPause feature, and some additional logging for it that’s been added in Sendmail 8.14.0.

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Sendmail 8.14.0: HeloName

February 8, 2007

Sendmail 8.14.0 was recently released, and it includes a small handful of patches that I sent in. The documentation explains what these options do, but doesn’t explain why you might want to use them. So I thought I’d do that in a series of entries here.

First, the new HeloName option.

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More adventures with VMWare

February 1, 2007

Well that Kubuntu experimentation didn’t last long.

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