Creates a .build_number file in your current directory which will store and increment the BUILD_NUMBER environment variable. This is useful when you want to keep track of build numbers outside of a continuous integration environment.

If the BUILD_NUMBER variable is already set, it will not be incremented.


Add this line to your application's Gemfile:

gem 'build_number'

And then execute:

$ bundle

Or install it yourself as:

$ gem install build_number


In your project's Rakefile:

require 'build_number'

# ENV['BUILD_NUMBER'] is now set and incremented for the next build.

Alternatively, you can get the value directly. In either case, the value will be incremented only once per build.

build_number = BuildNumber.current  # Reads the build number and increments the
                                    # value for the next build. Subsequent
                                    # calls return the same value.

You can also customize the name of the environment variable.

BuildNumber.env_var_name = 'A_CUSTOM_ENV_VAR_NAME'


  1. Fork it ( )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request