Mac本 Ruby安装成功 ruby -v好使，gem -v好使 rails 安装后rails -v 不好使

Question

MacBook-Pro:~ xxx$ ruby -v
ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-darwin21]
MacBook-Pro:~ xxx$ gem -v
3.3.11
MacBook-Pro:~ xxx$  sudo gem install rails
Password:
Successfully installed rails-7.0.3
Parsing documentation for rails-7.0.3
Done installing documentation for rails after 0 seconds
1 gem installed
MacBook-Pro:~ xxx$ rails -v
Rails is not currently installed on this system. To get the latest version, simply type:

    $ sudo gem install rails

You can then rerun your "rails" command.
MacBook-Pro:~ xxx$ 

Answer 1

用gem env命令看看这两个文件夹(INSTALLATION DIRECTORY, USER INSTALLATION DIRECTORY)在不在PATH里吧，没有就给添加进去，大概是这样的：

$ gem env
RubyGems Environment:
   -RUBYGEMS VERSION: 3.1.2
   -RUBY VERSION: 2.7.1 (2020-03-31 patchlevel 83) [x86_64-darwin19]
   -INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/2.7.0
   -USER INSTALLATION DIRECTORY: /Users/xxx/.gem/ruby/2.7.0

希望能帮助到你。