Bash Brace Expansion - Pivotal Labs

In our static assets directory, we have the following directories:

   public/images
   public/javascripts
   public/stylesheets

We want to namespace our application (my_app). We could type the following:

   mkdir public/images/my_app
   mkdir public/javascripts/my_app
   mkdir public/stylesheets/my_app

Or to save time, we could type:

   mkdir public/{images,javascripts,stylesheets}/my_app

This will create the three directories with one command.

For more information on bash curly brace expansion, checkout this article by Mitch Frazier on Linux Journal.

Another expansion I’ve used:

   cp file.txt{,.bak}
      cp file.txt file.txt.bak