Category Archives: tech

27 Feb
2014

Getting Started with Beanstalkd

I had a good experience implementing beanstalkd for the first time last week, so I thought I’d write down how that went and what I learned.

Why Beanstalkd?

My requirements were simply to add both asynchronous (for processing things like recalculating counts) and periodic (mostly for garbage collection) tasks to a PHP application. The application has a separate web application and backend API, both made of PHP’s Slim framework, and the API talks to MySQL. It’s all very lightweight and scalable, and I was looking for something to fit in with what we have, with good PHP support.

Enter beanstalkd, it’s a super-simple job queue and has great PHP support in the shape of Pheanstalk (I’m saving my PHP + beanstalkd examples for another day because this post would get too long to read otherwise!). I’ve used gearman in the past but beanstalkd seemed lighter, and when I started looking at their documentation I discovered that I had a working installation in about the time it would take me to fall off a log – which is always a good indicator of a tool that will be fun to work with :) Continue reading →

03 Feb
2014

Git Log All Branches

I can’t be the only person who always seems to be switching between multiple development branches. Sometimes I get distracted for a few days (I’m also part time, which doesn’t help!) and then I can’t even remember what I was doing or what the branch was called.

The remedy for this situation? The --all switch to git log. Continue reading →

30 Jan
2014

Ubuntu and the X220T Touch Screen

I have a thinkpad laptop with a touchscreen and a swivel so it can fold up and pretend to be an oversized tablet. I like it a lot, but the touch screen interface hasn’t been all that useful since I normally use this machine docked and then it maps the whole of one screen as a touch interface across my multiple monitors as a desktop space!

I recently sorted this out, so I thought I’d share the scripts that worked for me on Saucy Salamander Ubuntu 13.10 with Unity.

First, work out which device you actually want:


$ xsetwacom --list
Wacom Bamboo stylus id: 11 type: STYLUS
Wacom ISDv4 E6 Pen stylus id: 13 type: STYLUS
Wacom ISDv4 E6 Finger touch id: 14 type: TOUCH
Wacom Bamboo eraser id: 19 type: ERASER
Wacom Bamboo cursor id: 20 type: CURSOR
Wacom Bamboo pad id: 21 type: PAD
Wacom ISDv4 E6 Pen eraser id: 22 type: ERASER

Then, use xsetwacom to get the right touch input relating to the correct screen, even with multiple monitors:


$ xsetwacom set "Wacom ISDv4 E6 Finger touch" MapToOutput LVDS1

At this point I should point out that my touch screen is incorrectly configured and therefore needs the script above running every time I plug or unplug an external display. Since I dock my machine, move it almost daily, and regularly present … that’s kinda irritating. Any solutions on improving that are welcome.

20 Jan
2014

Splitting And Combining Odd/Even Pages With Pdftk

I’m working on a fun printable project at the moment, but part way through I realised I would need to process odd and even pages of the document separately. So separately, that I split the doc into two separate ones, with odd pages in one and event pages in another – and then had to recombine them. Here’s the commands that I used, with an excellent tool called pdftk. Continue reading →
06 Jan
2014

Upcoming Git Courses

Three git courses are coming up in the next few weeks, and a few people have asked me which courses I’m running, so here’s a quick roundup (feel free to drop me a line if you need any more detail):

  • Dublin, 30th January: Git and GitHub Foundations
  • Dublin, 31st January: Git and GitHub Advanced
  • London, 6th February: Git for Teams

I have fantastic partners for these events: the Dublin ones are with Github and the London ones with FLOSSUK, and I look forward to both. Right now they all do still have places remaining, visit my courses page for the links you need to book. Training days are a great opportunity to boost your skills and discuss specific aspects of technology that you can’t really get from a textbook – hope to see you at one of these sessions, I am standing by for difficult questions :)

31 Dec
2013

Git, Vimdiff, and Merge-Base

git merge-base is this week’s favourite git command. I use it to show me in a vimdiff everything that has changed on a particular branch since it was created. This took a little bit of looking around to find how to combine the tools, so I thought I’d write it all down in one place. Continue reading →
19 Dec
2013

Hiding Sections With Rst2pdf

I’ve been using rst2pdf for slides for a year or so, but recently I’ve been converted to using it for everything from documents to emailed reports to handouts. Along the way there were a couple of cases where I wanted to create two similar documents, but one needed to omit some details. A great example is my ZCE questions pack, which when updated to PHP 5.5 I converted to restructuredText. By showing/hiding different sections of the document when I generate the PDF, I can maintain the questions and their answers side-by-side, then create the documents containing questions and answers separately. You could do the same with adding a notes field to slides that are hidden when presenting, but available for handouts. Continue reading →
16 Dec
2013

Printing Many PDFs Per Page

Much of my work revolves around documents or slides, and I use PDF format for pretty much everything I do. In the last year or so I’ve developed a love affair with rst2pdf which means I’m doing more PDF now than ever.

This weekend I was working on a project which needed a programatically-generated PDF file to be many-slides-per-page – and for this I adopted a tool I haven’t used before: pdfjam (installed straight from apt on Ubuntu).

In fact it was pretty easy to get going with it: to print my existing PDFs at 4-per-page, I used this command:

pdfjam --landscape --nup 2x2 --a4paper -q slides.pdf -o handout.pdf

The slides themselves were already landscape so I specified the target document should also be landscape. The --nup 2x2 is the magic that prints many slides per page, and it seems like it can do various nice tricks with handouts. Running through the other arguments that I used: --a4paper for the paper size, -q to stop it from chattering (which it does by default, even when everything worked), slides.pdf was my input file and -o handout.pdf the target file to put the new layout into.

Until now I’ve mostly worked with pdftk for everything, but I couldn’t find a way to do this using it. Pdfjam is now a welcome addition to my PDF toolchain, so I thought I’d share.

10 Dec
2013

DimpleJs Bubble/Scatterplots and Joind.in Data

DimpleJs is a wrapper for d3, the javascript charting library, which makes beautiful charts but is way more complicated than I want to cope with, so I was looking for a helper toolkit. I’ve been using dimplejs lately and wanted to write down what I did while I can remember, but I didn’t think my clients would thank me for publishing their data! Instead, I made some graphs using Joind.in‘s data, just pulling what I needed over the API and producing something like this:



Continue reading →

09 Dec
2013

Open a GitHub Pull Request with Hub

Both in my professional life and in my personal life as an open source project lead, I spend a lot of time working with git in general, and GitHub in particular. GitHub publishes a command line tool called hub, which is a more convenient way than the website for doing a few specific tasks and in particular I’ve been using it more and more for opening pull requests. Continue reading →