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)

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.

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

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

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.

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

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!

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!

Wireshark Capture on Remote Server

The joind.in project uses a really nice vagrant setup for its dev platform - which is much needed these days as we move away from a single LAMP stack install to a website plus another website, which talks to an API and caches in redis and deploys with .... you get the picture :) This is great but having everything on the VM can make it a bit trickier to debug what's going on - and with a website that talks to an API that talks to MySQL, that all lives on a VM with port forwards, you can see the problem :)

To get an insight into the traffic going around the place, I've been using Wireshark and it's ability to capture remotely, it's really simple so I thought I'd write down my "recipe" on how to do this in case it's useful. Continue reading