Category Archives: tech

22 Jul
2014

My ffmpeg Cookbook

I have been doing more screencasting lately, so I thought I’d share some recipes here, for my own future use and in case anyone else wants to use them. I capture my videos using Kazam on Ubuntu, usually by resizing my second monitor to 800×600 and then capturing that. Kinda eye-bleeding to record but looks good in playback and also works well either in tiny web view or on a big screen. I also screencapture my android device and for that I use Screen Recorder.

Edit: I mostly used OBS for video from around 2019.

Continue reading →

08 Jul
2014

View Only Headers with Curl

When working with curl, it can give lots of excellent and detailed information, but sometimes it is too much! Today I’m fiddling with the caching headers on a client’s application, so I’m only interested in seeing the headers and not the body of the response. Making a HEAD request changes the output I get, so I really do want to GET and then only see the headers.

Handily, when you use the -v verbose flag with curl, it sends the output to stdout as usual, but the extra information including the headers goes to stderr. This means that I can therefore view the headers only throwing away stdout completely:

curl -v -s http://awesome-site.com 1> /dev/null

(you need the -s to stop curl from “helpfully” printing progress bars as well)

03 Jul
2014

Video: Git Remotes and Tracking Branches

Here’s a little demo video that I put together to explain pushing/pulling with multiple remotes and how tracking branches make this easier. It’s one of the chapters from my “Git Adventures” talk, but it didn’t make it in to the talk in Amsterdam last week since we chose a different adventure that time – sharing it here in case it’s helpful to anyone else, and so I can find it later!

I also blogged about the tracking branches in a bit more detail if you’re interested.

03 Jul
2014

Understanding Tracking Branches in Git

Here’s a topic that took me a while to understand in git, and now (I think!) I do, I thought I’d write it all down while I can remember!

Some branches in git (such as your origin/master branch) will usually track the remote branch that they are related to. But what if you want to create a relationship between local and remote branches? Or stop them from tracking? Here’s some pointers Continue reading →

01 Jul
2014

Running Pull Request Builds with Jenkins

The joind.in projects are set up so that the build process runs on pull requests when they are opened, which is great! It means that contributors don’t have to wait for one of the maintainers to look at it, only to reject the contribution on something that could be picked up automatically. I’ve had a few questions about the setup so I thought I’d share how it works. Continue reading →
12 Jun
2014

What Got You Involved in Open Source?

I did a very unscientific twtpoll recently regarding what brought each of us into open source. Plenty of people took the time to vote or retweet, so I thought I’d loop back around and let you know how it looked overall when the poll closed. Continue reading →
02 Jun
2014

Colourless Git Output

I teach git and often have issues with bad projectors where you can’t see the colours. Recently I had a setup where even white on black was more or less invisible, but using black text on a white background worked okay. There’s lots of documentation on how to turn on colours in git but not so much about how to turn them off.

Try putting the following into .git/config:

[color]
    branch = false
    diff = false
    interactive = false
    status = false

I had expected to be able to set color.ui to false but that didn’t seem to make much difference, so I now use the settings above. I thought I’d drop it here in case anyone else is looking for the same thing.

13 May
2014

Easy Lint Check for JavaScript

I’m introducing lint checking on one of my projects, because it didn’t have a build process yet and I love this as a great place to start. Oh, and because we managed to commit broken syntax! So I set up a php lint job (I will share my travis config in another post) and tried to work out doing the same thing for JavaScript. Continue reading →
02 Apr
2014

Copy/Pasting and Vim

I’m a vim user and I somehow completely missed this excellent feature until much more recently than I care to admit! Usually vim has its own clipboard, but it doesn’t share with the operating system. You will need a vim-gtk install, this isn’t available in really basic vim (I’m a little unclear exactly on the dependencies).

To paste between vim and something else, use the + (plus) buffer in vim. It contains the contents of your system clipboard, and you can also write to it. If you’re not already using buffers in vim, then you should probably read the excellent documentation but for a very quick start:

  • To copy something into the buffer, select it in visual mode and type "+y
  • To paste from the buffer, type "+P

I had no idea how I’d missed this really fundamental trick, so I thought I’d share!

31 Mar
2014

Quick Switch Between Git Branches

Today’s little-known git feature (or maybe everyone knows but me? I only found this a few months ago) is for quickly switching between branches. Usually I would switch branches with:

git checkout [branchname]

However if you switch from one branch to another and want to switch back again (this happens when I’m reviewing changes and wondering if a bug is present on master as well), then you can do so by just doing:

git checkout -

Just a little timesaver in case it’s useful to anyone else – I know I’ve been using it quite a bit!