Automatically Generating Ctags with Git Hooks

As an avid Vim user, I am always searching for faster ways to do things. When I learned about the amazing power of Ctags, I was excited that I finally found a way to quickly move to the definition of a method or class. I generated my Ctags once, and then I was fine for a while. But then, after the code changed enough, I would keep running into methods and classes that weren’t in my tags, and therefore I couldn’t jump to their definition. This is where generating them automatically comes in handy.

While there are probably a ton of ways to automatically generate Ctags, my personal favorite now is using Git hooks. Git hooks are basically little scripts that get run after some event happens in Git. For example, the one I am going to use in this post is post-checkout. This means the script is run every time you checkout a branch in Git.

Now that we know about Git hooks, all we need to do is add a line to some Git hooks to generate Ctags whenever certain things happen in Git. I personally set it up to generate Ctags after I checkout a branch in Git. This can be done in two simple and elegant lines of bash that you run from the root of the git repo:

  echo "ctags -R --languages=ruby ." > .git/hooks/post-checkout
  chmod +x .git/hooks/post-checkout

The first line writes the ctags command to the post-checkout Git hook file. The second line just makes the post-checkout hook executable. Of course you can customize the options for the ctags command as you please.

It’s that simple! If you want to generate Ctags more often, you can just run the same two lines above but replace post-checkout with whatever hook you want to use.