Finding a route from one wikipedia page to another
Here’s a game I like to play. Select two wikipedia pages at random, and find a route from one to the other. I stated a theorem once that: you can get from any page on wikipedia to the page on…
kostas
Running Nagios on Amazon EC2
This howto shows how to get Nagios up and running on an Amazon EC2 Instance using Apache web server to serve the Nagios UI. You could argue that a more light-weight web server would be better, but I’d argue that…
CORS and Google Fusion Tables
Google Fusion Tables is a service for storing tabular data online. It has an API that allows you to make an SQL-like request for data from an online table, like the following: sql=SELECT * FROM 1906375 (clicking the link will…
Using CORS instead of JSONP to make cross site requests
Introduction to CORS CORS (Cross Origin Resource Sharing) is a mechanism specifies by W3C (draft), for allowing browsers to make cross origin requests for resources on other domains under certain conditions. It’s related to JSONP because it solves a similar…
How to put each word in a file on a separate line
Place each word on a separate line with sed and awk: sed -e ‘s/[^[:alpha:]]/ /g’ | awk ‘{ for (i=1;i
Testing a rhyme hypothesis
I read somewhere that if you take a list of words reverse the letters in each word sort the (reversed) words alphabetically then reverse the words back to normal
How to group by date in Oracle database
I keep forgetting how to do this. How to group on a date column (date_col in the example) in Oracle: SELECT count(*) FROM table GROUP ON TO_CHAR(date_col, ‘DD-MON-YYYY HH:MI:SS’) For other format strings than ‘DD-MON-YYYY HH:MI:SS’ see this page.
How to split a log file into smaller files
In this example I had a big log file (many million lines), that I wanted to split into smaller logfiles (each one million lines) for processing on Elastic MapReduce. -rw-r–r– 1 kostas staff 543067012012 Oct 11 13:45 huge_logfile This is…
China in a few years?
Completely off topic. Just a thought, is this what China will look like in a few years? A country of old people, governed by the children of the one-child policy era… Wonder how that will affect the current financial situation…
OpenStreetMap tiles with custom projection and grid using Mapnik
Previous effort In a previous post I tried generating OpenStreetMap tiles using GeoServer. It ended when I couldn’t find a good style (SLD) to apply the OSM layer. The (new) idea, that also failed miserably In this post I tried…