Archive for August, 2004

Starting some development work:- wxPython vs Python web

I’m in the process of developing a small application for stock purchase management. Basically logistics handling for purchasing containers from an overseas supplier, dealing with some forecasting for supply cycles. Few basic things.

I haven’t really done much development work a very long time, so I’m a bit rusty. I decided that I’m going to write it in python, as after looking at some of my old perl programs I realise how important it is to be able to maintain your applications even six months down the track. So I think its probably a good change to learn some python and see if its works for me. I’m quite interested in the statement I constantly have heard: “I sat down to try test some ideas and had my application written over the weekend.”

The question I’m now faced with though what UI to use. Should it be web based or maybe wxPython? Problem is when you are writing something not for yourself to use, but other users that you have to make sure that its robust and finding debugs is not going to make you hair go grey.

I gave SPE a try last week and quite liked it. I was almost ready to buy wingware, but SPE seems somewhat better. I had a play in the windows version with its interface to wxGlade. It looked very powerful, I’m figuring it might take me about a couple learning how to put basic single window applications together and maybe another ten or so, put it all together in a multi-window application.

On the web side, as many people know that are a lot of different choices for python web applications frameworks. I still have to write the data model and I’ll probably try wxPython out, but a web application is easier to deploy and upgrade, and I’m a lazy admin.

I’ve been compiling a list of references:

Still a bit of work to do.

Comments off

Strang on Video

Always enjoyed Strang book, now he has some video lectures up on the net: 18.06 Linear Algebra Videos Fall 1999.

By this account the video lectures are very good.

Comments off

Jogin.com :: Tables

Nice tale about designing two sites, one with tables vs the other with css layouts.

Interesting commentry afterwards with a reference to a nice quick introduction to Developing With Web Standards.

Comments off

TCP window scaling and broken routers

Something to be aware of when you upgrade to 2.6.8.1, TCP window scaling and broken routers:

In the 2.6.7 kernel, the default scale factor is zero; in Linus’s BitKeeper tree and the 2.6.7-mm kernels, instead, it has been increased to seven. This change has brought the broken router behavior to light; suddenly people running current kernels are finding that they cannot talk to a number of systems out there. One of the higher-profile affected sites is packages.gentoo.org. Gentoo users are, unsurprisingly, not pleased.

In the mean time, anybody running a current kernel who is having trouble connecting to a needed site can work around the problem with a command like:

echo 0 > /proc/sys/net/ipv4/tcp_default_win_scale

or by adding a line like:

net.ipv4.tcp_default_win_scale = 0

to /etc/sysctl.conf.

Comments off

Syslog logging to a Database

Planning to move to a centralised logging system using a database. Mainly so I can keep log entries around for at least 6 months, plus to make it easier to find and sort entries with one of the php based log-display systems.

Couple of methods avaliable that look interesting: Syslog Logging with PostgreSQL HOWTO and Centralized syslog-ng to Mysql.

Will have to investigate further.

Comments off

Earth at Night part ii

Following up from the Earth at Night post a few days back, here is a slashdot post with a link to a site with a population density map.

Comments off

Icon warning messages in KDE

Using kprinter directly would often bring on a whole pile of warning messages like “kdecore (KIconLoader): WARNING: Icon directory /usr/share/icons/hicolor/ group 48×48/stock/media not valid” for empty directories. Annoying to say the least.

Final forced myself google for a solution. I must say the KDE has some real nice flexibilities in configuration.

Comments off

Earth at Night

Astronomy Picture of the Day is a constant source of interesting view-points on our universe.

I think it would be revealing if we overlayed a population density with todays picture. You would probably see which parts of the world have a high level of living compared to those that don’t.

Comments (1)

Is that a PC is your pocket?

I’m not sure I trust Sony, but the Sony U-70 sure looks sexy. Small nootbooks and PDAs are rapidly converging on each other. Another interesting unit is the Pocket Loox 720 by Fujitsu. Particular since it can “operate as a USB 1.1 host”.

Last year I almost bought a Fujitsu P-1120. In the end I decided both that it didn’t have USB2 and that I could wait. Although it could fit in a pocket, it just didn’t quite seem to have enough modern features.

Now that I’m off the beast-master system upgrade horse, having replaced my gaming platform with the XBox, and in the process saving myself a lot of cash. My remaining goal is too thin-client myself. With a combination of Win4Lin, Crossover, KDE and NX running on top of UML, I can set myself up almost anywhere running almost anything.

These pocket based systems combined with WiFi and GPRS certainly seem like a good step along that way. Your front end becomes nearly throw-away.

Comments off

Passwords

Remebering passwords is a chore, its becoming more important with the ready increase in cracking power. I can just see some windows worm being designed right now to provide more distributed horse-power to crack passwords and distributed disk space to create massive password dictionaries. Combined with a little more cunning, these beasts are going to start automatically cracking passwords on systems they compromise.

There was a recent discussion on debian-user with some clever ideas for generating passwords.

Personally I agree with Karsten M. Self. Eventually the best way to secure our systems is going to be with tokens.

Comments off