要完成其他答案，gem-path gem可以找到特定gem的安装路径。

安装:

gem install gem-path

用法:

gem path rails
=> /home/cbliard/.rvm/gems/ruby-2.1.5/gems/rails-4.0.13
gem path rails '< 4'
=> /home/cbliard/.rvm/gems/ruby-2.1.5/gems/rails-3.2.21

这真的很方便，因为你可以用它来grep或编辑文件:

grep -R 'Internal server error' "$(gem path thin)"
subl "$(gem path thin)"

你可以欺骗gem open显示gem路径:

VISUAL=echo gem open gem-name

例子:

VISUAL=echo gem open rails
=> /usr/local/opt/asdf/installs/ruby/2.4.3/lib/ruby/gems/2.4.0/gems/rails-5.1.4

它只是工作，没有第三方宝石是必要的。

gem env列出了可以安装宝石的位置，但可以是10个或更多的位置。如果你想知道一个特定的gem被安装在哪里，你可以执行:

gem list -d <gemname>

示例输出:

tilt (2.0.9)
    Author: Ryan Tomayko
    Homepage: http://github.com/rtomayko/tilt/
    License: MIT
    Installed at: /opt/rubies/ruby-2.5.3/lib/ruby/gems/2.5.0

    Generic interface to multiple Ruby template engines

我发现它有用的库文件的位置:

gem which *gemname*

宝石环境工作就像宝石环境。节省一些输入。

# gem env
RubyGems Environment:
  - RUBYGEMS VERSION: 2.0.14
  - RUBY VERSION: 2.0.0 (2014-02-24 patchlevel 451) [i686-linux]
  - INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/2.0.0
  - RUBY EXECUTABLE: /usr/local/bin/ruby
  - EXECUTABLE DIRECTORY: /usr/local/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86-linux
  - GEM PATHS:
     - /usr/local/lib/ruby/gems/2.0.0
     - /root/.gem/ruby/2.0.0
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - https://rubygems.org/

要完成其他答案，gem-path gem可以找到特定gem的安装路径。

安装:

gem install gem-path

用法:

gem path rails
=> /home/cbliard/.rvm/gems/ruby-2.1.5/gems/rails-4.0.13
gem path rails '< 4'
=> /home/cbliard/.rvm/gems/ruby-2.1.5/gems/rails-3.2.21

这真的很方便，因为你可以用它来grep或编辑文件:

grep -R 'Internal server error' "$(gem path thin)"
subl "$(gem path thin)"