Keyword expansion with attribute filters

With version control systems such as Subversion, RCS, and so on, it is possible to insert a number of keywords in a file, and these will then be expanded/collapsed on checkout/add. The same functionality can be achieved with Git, though a bit of setting up is required, as it is not built into Git's core. The attributes functionality of Git can be used to create filters for the keyword substitution. In the following example, we'll see how we can easily exchange the $Date$ keyword with a string such as $Date: Sun Apr 27 14:17:24 2014 +0200$ on checkout.

Getting ready

In this example, we'll use the repository located at https://github.com/dvaske/attributes_example.git. Take a look at the keyword branch using the following command:

$ git clone https://github.com/dvaske/attributes_example.git
$ cd attributes_example
$ git checkout keyword

How to do it...

First, let's create the filters needed to substitute the keyword on add and checkout. The filters are...