Stability of email addresses

Massey‘s ITS department have been at it again (see also the comments about their security blunder earlier this year – somewhat patched up now).

Ever since email began, it has been customary for an email address to take the form username@domain – for example, I have a username “ta-meyer” with which I log into Ihug, and so I have an email address ta-meyer@ihug.co.nz. Massey (staff) usernames typically come in the form initial(s)surname (e.g. my name is Tony Andrew Meyer, so my username is “tameyer”). As such, you would expect my Massey email address to be tameyer@massey.ac.nz (just as you find my web page by putting Massey’s address, then a tilde (for ‘home’) then my username, to get http://www.massey.ac.nz/~tameyer).

Until some time in the last week, you would have been right. You could also have used t.a.meyer@massey.ac.nz (note the dots), but it didn’t really make as much sense (“t.a.meyer” is no good as a username, anywhere at Massey), and is more difficult for people to remember. Just recently, however, mail to username@massey.ac.nz (e.g. tameyer@massey.ac.nz) has started to bounce with an “unknown user” error.

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Finding libstdc++.so.6

When I tried to build Python 2.4.1 on doublehelix I ran into two problems:

  • configure wouldn’t complete, saying that it couldn’t run compiled C programs.  I looked at the configure script and right before this it had something about not removing this section with autoconf 3.0:
# FIXME: These cross compiler hacks should be removed for Autoconf 3.0
# If not cross compiling, check that we can run a simple program.

So I went ahead and commented out that section and it ran.  I suspect that this was actually caused by the second problem.
  • make ran fine until it tried to use python to build the extension modules (or if I tried to run python manually once it was built).  I got “./python: error while loading shared libraries: libstdc++.so.6: cannot open shared object file: No such file or directory”

There’s a lot of stuff online about this problem, and generally the solution is to either modify /etc/ld.so.conf to include a path to the library, or put the path on LD_LIBRARY_PATH.  I don’t have access to /etc/, so the second seemed like the best plan.  A simple ‘find / -name libstdc++.so.6’ found three files with the right name, so I put the first one (/usr/local/lib) into LD_LIBRARY_PATH.

Unfortunately, this didn’t work – nothing seemed to change at all. I tried lots of other things, but nothing worked.

The problem turned out to be that although they all had the same name, the three libstdc++.so.6 files were not the same (I imagine that one is specific to 64 bit compiling).  If I put the one in /lib64/ssa on LD_LIBRARY_PATH, all worked nicely (what normally goes into /lib64/ssa, I do not know).

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The importance of priority

As part of my PhD research, I have to link together a lot of separate components, many of which are running on separate machines, as they’re too much for a single one. You’d think that this was relatively simple, given that a good non-blocking synchronous socket module is part of the standard Python library. Not so! Everything always runs too slowly, even when it’s the only thing running on the machine.

The first time I came across this problem, I was running the vision module and the speech module on the same machine, which communicated with the graphics module on a different one. The speech module just wouldn’t run nicely at all.

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Tagline

I should also explain the tagline, I suppose.  Some time back, my Dad asked me about the etymology of “blog”, and said that his best guess was “bullshit, lies, or gossip”.

While not technically correct, it did seem pretty accurate in a lot (not all, of course) of cases.  While hopefully this blog won’t contain bullshit, lies or gossip, I liked the line.

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About

So, what is the purpose of this blog?  Basically, it’s replacing the content that’s under “miscellaneous writing” on my Massey website.  That’s getting a little unruly, and, more importantly, my time at Massey (10 years!) is just about up, so no doubt that site will get killed at some point.

The material that’s there is a combination of things – drafts or extended versions of things I post elsewhere, little notes about things that I had to figure out myself rather than use Google (ideally letting me, and maybe others) find them later, and a few other bits and pieces.

This really isn’t designed for anyone else to read (IMO, not every blog needs to be). If you find a useful post here, don’t bother subscribing – just keep using Google, and it’ll point you back here if anything else is of use.  This might change in the future, but that’s the way it is now.

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Reply All

This is primarily intended for people corresponding with me via spambayes@python.org.Those that have will have noticed my signature generally includes these lines:

--
Please always include the list (spambayes at python.org) in your replies
(reply-all), and please don't send me personal mail about SpamBayes.
http://www.massey.ac.nz/~tameyer/writing/reply_all.html explains this.

Here is an explanation of what that means, why I am asking you to do this, and how you can do it. If you don’t understand a term here, please check the list at the end for a definition, or use Google‘s “define” facility to get a definition.

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