What does `@something` stand for in `rvm use 2.0.0@something`?

Question

As the title says, can't find any documentation on what @something does in rvm use 2.0.0@something?

Answer 1

RVM is the Ruby Version Manager and its website is here: https://rvm.io/

The command rvm use 2.0.0@something tells RVM to change the setup of your current shell (terminal) so that you are using ruby 2.0.0. It also says to use the gemset named something. Gemsets are a feature of RVM that let you segregate your Ruby gems into different sets.

More information about gemsets is here: https://rvm.io/gemsets/basics

Answer 2

Suppose you are working on three parallel projects: one uses Ruby 1.9.3 and two use Ruby 2.0.0. Lets say:

• Project A: Ruby 1.9.3
• Project B: Ruby 2.0.0
• Project C: Ruby 2.0.0

When you are working on Project A, you can just say rvm use 1.9.3, and it will set your current Ruby version to 1.9.3.

Problems arise when you are working on Project B or C, and they are using different versions of the same gem (lets say Project B uses httparty 1.0, and project C uses httparty 2.0).

In this case, rvm not only allows you to use different rubies by using rvm use, but also allows you to use different sets of gems with each Ruby (called gemsets).

So you can just say(When on project B): rvm use 2.0.0@project_b_gemset (and this will install all the gems required for project B as a different set)

When you are on project C, you can just say rvm use 2.0.0@project_c_gemset, and this will install all of the gems required for project C as a different set. And hence you can use different sets of gems with the same Ruby version.

Summing up:

rvm use ruby_version@gemset_version:

ruby_version allows segregation on the basis of Ruby versions and gemset_version allows you to do further segregation inside the same version of Ruby.