Ruby: share common variables and methods across a set of scripts

Answer 1

1. Use capital letters for your constants (HOME_DIR_PATH, not home_dir_path)
2. Put your methods inside a module.

You can call your methods through the module, or you can include the module in your namespace and call them directly (Sarah has code for all of this)

Answer 2

Wrap your methods and variables in a module, e.g.

module CommonStuff
    USERNAME=ENV['USER']
    HOME_DIR_PATH=ENV['HOME']

    def print_and_execute(command, &block)
        ...
    end
end

Then script1.rb might be like:

#!/usr/bin/env ruby
require File.dirname(__FILE__) + '/commonstuff.rb'
include CommonStuff

puts HOME_DIR_PATH         # Win
print_and_execute "date"   # Win

Or, if you don't want to include the module in your namespace:

#!/usr/bin/env ruby
require File.dirname(__FILE__) + '/commonstuff.rb'

puts CommonStuff::HOME_DIR_PATH         # Win
CommonStuff.print_and_execute "date"   # Win

See also Modules and the Programming Ruby page on modules.