As a reminder, I was very worried about installing ruby through rbenv.

What is rbenv in the first place?

Tools for switching and managing ruby versions

Next, I will post the installation procedure (Mac).

Installation procedure

Rough flow

Install Homebrew
Install rbenv via Homebrew
Install ruby via rbenv

1. Install Homebrew

Open the terminal It is around the installation of Homebrew

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"

Paste and run This will install Homebrew.

2. Install rbenv via Homebrew

Once Homebrew is installed, then

$brew install rbenv

Enter the command. Enter rbenv -v to check the version of rbenv

3. Install ruby via rbenv

Next, I will install ruby, but to check if there is a desired version

$ rbenv install -l
1.8.5-p52
1.8.5-p113
1.8.5-p114
1.8.5-p115
1.8.5-p231

(Omitted)

It will be displayed. If the desired version is not in this, it may not be displayed if the version of rbenv is old. Type $ brew upgrade rbenv ruby-build to update.

If you have the desired Ruby, enter the following to install Ruby.

$ rbenv install (version of target ruby)

How to verify Ruby installation through rbenv

$rbenv version

(Target version) (set by /Users/(username)/.rbenv/version)

You can check the version by typing.

Where I stumbled

Has the Ruby version changed?

Although it is good to install ruby through rbenv

$ruby -v

(Numbers not the desired version)

It was displayed that it was different from the one shown in $ rbenv version.

As a cause

I found out after a lot of research It is a phenomenon caused by the fact that the referenced Ruby has not changed. Originally, Mac already has Ruby, and it refers to the existing Ruby. So, make sure to pass the path to refer to Ruby installed by rbenv.

As a solution

You just have to go through the path, but what do you do? Just write in ~ / .bash_profile to refer to Ruby installed by rbenv

.Bash_profile is a file that is executed at login.

$cd $vi ~/.bash_profile

Since there is .bash_profile in the home directory, go to the home directory and go to the home directory Open .bash_profile with vi and write the following

export PATH="~/.rbenv/shims:/usr/local/bin:$PATH"
eval "$(rbenv init -)"

After writing with vi,

source ~/.bash_profile

Enter and restart to change the Ruby version and you're done.

References

Manage ruby version with rbenv What to do when the Ruby version does not switch! What is the difference between .bash_profile and .bashrc

How to install ruby through rbenv