brew link --overwrite --force ruby

您可以通过查看下载Ruby指定Ruby的最新版本。

获取最新版本: curl -sSL https://get.rvm.io | bash -s stable——ruby 安装: RVM安装2.2 使用它作为默认值: RVM使用2.2——default

或者运行ruby的最新命令:

rvm install ruby --latest
rvm use 2.2 --default

在终端:rvm gemset使用全局

我推荐rbenv* https://github.com/rbenv/rbenv

*如果这符合你的标准:https://github.com/rbenv/rbenv/wiki/Why-rbenv?:

rbenv does… Provide support for specifying application-specific Ruby versions. Let you change the global Ruby version on a per-user basis. Allow you to override the Ruby version with an environment variable. In contrast with RVM, rbenv does not… Need to be loaded into your shell. Instead, rbenv's shim approach works by adding a directory to your $PATH. Override shell commands like cd or require prompt hacks. That's dangerous and error-prone. Have a configuration file. There's nothing to configure except which version of Ruby you want to use. Install Ruby. You can build and install Ruby yourself, or use ruby-build to automate the process. Manage gemsets. Bundler is a better way to manage application dependencies. If you have projects that are not yet using Bundler you can install the rbenv-gemset plugin. Require changes to Ruby libraries for compatibility. The simplicity of rbenv means as long as it's in your $PATH, nothing else needs to know about it.

安装

安装Homebrew http://brew.sh

然后:

$ brew update
$ brew install rbenv ruby-build

# Add rbenv to bash so that it loads every time you open a terminal
echo 'if which rbenv > /dev/null; then eval "$(rbenv init -)"; fi' >> ~/.bash_profile
source ~/.bash_profile

$ rbenv install --list
Available versions:
 1.8.5-p113
 1.8.5-p114
 […]
 2.3.1
 2.4.0-dev
 jruby-1.5.6
 […]
$ rbenv install 2.3.1
[…]

设置全局版本:

$ rbenv global 2.3.1
$ ruby -v
ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-darwin15]

如果您没有显示更新的版本，那么

$ rbenv rehash

通过在存储库根目录中添加.ruby-version来设置存储库的本地版本:

$ cd ~/whatevs/projects/new_repo
$ echo "2.3.1" > .ruby-version

对于OS X，请访问此链接。

最简单的方法肯定是在终端输入以下命令:

sudo gem update --system

如果不想下载文档，可以添加标记——no-document。下面是运行命令后的输出示例:

sudo gem update --system
Password:
Updating rubygems-update
Fetching: rubygems-update-2.6.8.gem (100%)
Successfully installed rubygems-update-2.6.8
Parsing documentation for rubygems-update-2.6.8
Installing ri documentation for rubygems-update-2.6.8
Installing darkfish documentation for rubygems-update-2.6.8
Installing RubyGems 2.6.8
RubyGems 2.6.8 installed
Parsing documentation for rubygems-2.6.8
Installing ri documentation for rubygems-2.6.8

------------------------------------------------------------------------------

RubyGems installed the following executables:
    /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/gem

Ruby Interactive (ri) documentation was installed. ri is kind of like man
pages for ruby libraries. You may access it like this:
  ri Classname
  ri Classname.class_method
  ri Classname#instance_method

一种快速将Ruby升级到v2.4+的方法

brew upgrade ruby

or

sudo gem update --system