Why doesn't gem install bundler work?

Question

I am trying to deploy an application via Github pages, and based on this tutorial that I am watching, I need to install bundler first.

When I type in the command gem install bundler, I get the error:

While executing gem ... (Gem::FilePermissionError) You don't have write permissions for the /Library/Ruby/Gems/2.0.0 directory.

I do not have rbenv downloaded and I don't know how to. I also do not fully understand the concept of gems.

How can I bypass this issue?

Answer 1

Try 'sudo gem install bundler'