Howto



Articles tagged 'howto'

2009-05-23
Family tree using Graphviz and Ruby

My dad spent a lot of time putting together a family database, currently containing about 12000 people covering both my parents ancestors as well as tracking forward to contain a lot of living descendants. Unfortunately, since he started this over 16-17 years ago it's been managed as a custom dBase III+ ...

2009-05-18
Making Graphviz output pretty with XSL

NOTE: See the updated version of this stylesheet HERE

UPDATED: Example of the latest version here

A couple of years back I posted some about an XSL transformation I used to clean up Graphviz output to make my diagrams prettier. These days I use Omni Graffle for most of ...

2009-04-20
Updated Graphviz tools on Github

I just added a new repository on GitHub containing the tools from my Graphviz / diagram related posts.
The repository can be found at: http://github.com/vidarh/diagram-tools/tree/master

These are the ones included and the appropriate articles:

2009-02-03
Simple charts in Ruby using SVG::Graph

One thing that comes up time and time again when I mess around with a system, is quickly looking at frequencies of various things - for example disk usage by sub-directory, or referrer entries in my Apache access log.  Like this:http://librsvg.sourceforge.net/

# cat /var/log/httpd/access_log | cut -d' ' -f11 | grep ...

2009-01-31
Creating Graphviz graphs from Ruby arrays

As part of my compiler project I wanted a way to visualize the programs, and since the syntax tree (so far at least) is represented with plain Ruby arrays I decided to throw together a script to use Graphviz to generate some graphs. I've written about using Graphviz ...

2008-06-10
5 simple ways to troubleshoot using Strace

I keep being surprised how few people are aware of all the things they can use strace for. It's always one of the first debug tools I pull out, because it's usually available on the Linux systems I run, and it can be used to troubleshoot such a wide variety of ...

2008-05-15
How to beat comment spam (for now, anyway)

I've always loathed captcha's, and they've gotten progressively worse. But I've noticed some blogs seem to do reasonably well with just a single static word, presumably because most spammers won't customize things for a single blog unless you get a lot of traffic.

I also have a soft spot for an ...

2008-04-29
When your Linux / iptables firewall randomly drops connections...

Yesterday our firewall at work started randomly dropping connections. It has probably happened a few times before, but been seemingly resolved before I had a chance to look at it.

Weirdly, some people in the office reported no problems, while others couldn't even get DNS lookups to work properly.

Looking at ...