Today I Learned

Passing all env. variables to a shell command

Some of the methods in the Kernel module allows you to pass environment variables to a shell command. So rather than doing:

system("RAILS_ENV=test rake do_stuff")

You can do

system({ "RAILS_ENV" => "test" }, "rake do_stuff")  

This is particularly useful when we want to pass all environment variables on our current process.

system(ENV, "rake do_stuff")