rbenv: A basic introduction
We have projects that have been developed using many different versions of Ruby. Since we do not want to constantly update every old project, we need to have many Ruby versions installed on our development machines.
Rbenv does that for us.
How it works
Rbenv installs ruby version and ruby gems to
~/.rbenv/versions/VERSION_NUMBER/.... This way many different Rubies can be installed at once.
When you run
bundler or any other Ruby binary
- rbenv looks for a file
.ruby-versionin your directory (or any parent directory)
- and sets your
PATHto the correct Ruby on the fly
Check our card on installing rbenv.
Choose your version
To use a specific Ruby version for your project, add a file
.ruby-version that simply contains the version you want:
If you need to switch the version outside of a project for your current shell, you can also say
rbenv shell 2.3.1
Note that this causes your shell to ignore the
.ruby-version until you close it.
Show current version
To see the currently selected version (hopefully "2.3.1"), run
It will warn you if the version is not currently installed.
Install a missing version
rbenv install 2.3.1
You can skip the version number to install the currently selected one.