Answers:
用于gem environment了解您的宝石环境：
RubyGems Environment:
- RUBYGEMS VERSION: 2.1.5
- RUBY VERSION: 2.0.0 (2013-06-27 patchlevel 247) [x86_64-darwin12.4.0]
- INSTALLATION DIRECTORY: /Users/ttm/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0
- RUBY EXECUTABLE: /Users/ttm/.rbenv/versions/2.0.0-p247/bin/ruby
- EXECUTABLE DIRECTORY: /Users/ttm/.rbenv/versions/2.0.0-p247/bin
- SPEC CACHE DIRECTORY: /Users/ttm/.gem/specs
- RUBYGEMS PLATFORMS:
- ruby
- x86_64-darwin-12
- GEM PATHS:
- /Users/ttm/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0
- /Users/ttm/.gem/ruby/2.0.0
- GEM CONFIGURATION:
- :update_sources => true
- :verbose => true
- :backtrace => false
- :bulk_threshold => 1000
- REMOTE SOURCES:
- https://rubygems.org/
- SHELL PATH:
- /Users/ttm/.rbenv/versions/2.0.0-p247/bin
- /Users/ttm/.rbenv/libexec
- /Users/ttm/.rbenv/plugins/ruby-build/bin
- /Users/ttm/perl5/perlbrew/bin
- /Users/ttm/perl5/perlbrew/perls/perl-5.18.1/bin
- /Users/ttm/.pyenv/shims
- /Users/ttm/.pyenv/bin
- /Users/ttm/.rbenv/shims
- /Users/ttm/.rbenv/bin
- /Users/ttm/bin
- /usr/local/mysql-5.6.12-osx10.7-x86_64/bin
- /Users/ttm/libsmi/bin
- /usr/local/bin
- /usr/bin
- /bin
- /usr/sbin
- /sbin
- /usr/local/bin请注意以下两个部分：
INSTALLATION DIRECTORYGEM PATHSgem env简称
EXECUTABLE DIRECTORY。
EXECUTABLE DIRECTORY包含由宝石安装CLI可执行版本，但它不是宝石本身。
我发现使用以下命令获取库文件的位置很有用：
gem which *gemname*gem which 'logstash/inputs/tcp.rb'
安装宝石后，如果您想知道特定宝石在哪里。尝试输入：
gem list您将能够看到已安装的gem的列表。现在使用bundle show并命名您想知道其路径的宝石，如下所示：
bundle show <gemName>Could not locate Gemfile or .bundle/ directory。
gem env）仅显示文件夹的父文件gems夹：/home/test/.rbenv/versions/2.5.0/lib/ruby/gems/2.5.0。里面有很多文件夹，您的gem可能位于其中的几乎任何一个文件夹中-这bundle show <gemName>正是准确显示的（而gem env）却没有。
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这非常方便，因为您可以使用它来grep或编辑文件：
grep -R 'Internal server error' "$(gem path thin)"
subl "$(gem path thin)"您可以通过运行gem help commands然后选择适当的命令，从命令提示符处进行检查：
kirti@kirti-Aspire-5733Z:~$ gem help commands
GEM commands are:
build Build a gem from a gemspec
cert Manage RubyGems certificates and signing settings
check Check a gem repository for added or missing files
cleanup Clean up old versions of installed gems in the local
repository
contents Display the contents of the installed gems
dependency Show the dependencies of an installed gem
environment Display information about the RubyGems environment
fetch Download a gem and place it in the current directory
generate_index Generates the index files for a gem server directory
help Provide help on the 'gem' command
install Install a gem into the local repository
list Display gems whose name starts with STRING
lock Generate a lockdown list of gems
mirror Mirror all gem files (requires rubygems-mirror)
outdated Display all gems that need updates
owner Manage gem owners on RubyGems.org.
pristine Restores installed gems to pristine condition from
files located in the gem cache
push Push a gem up to RubyGems.org
query Query gem information in local or remote repositories
rdoc Generates RDoc for pre-installed gems
regenerate_binstubs Re run generation of executable wrappers for gems.
search Display all gems whose name contains STRING
server Documentation and gem repository HTTP server
sources Manage the sources and cache file RubyGems uses to
search for gems
specification Display gem specification (in yaml)
stale List gems along with access times
uninstall Uninstall gems from the local repository
unpack Unpack an installed gem to the current directory
update Update installed gems to the latest version
which Find the location of a library file you can require
yank Remove a specific gem version release from
RubyGems.org
For help on a particular command, use 'gem help COMMAND'.
Commands may be abbreviated, so long as they are unambiguous.
e.g. 'gem i rake' is short for 'gem install rake'.
kirti@kirti-Aspire-5733Z:~$ 现在从上面我可以看到该命令environment很有用。所以我会做：
kirti@kirti-Aspire-5733Z:~$ gem help environment
Usage: gem environment [arg] [options]
Common Options:
-h, --help Get help on this command
-V, --[no-]verbose Set the verbose level of output
-q, --quiet Silence commands
--config-file FILE Use this config file instead of default
--backtrace Show stack backtrace on errors
--debug Turn on Ruby debugging
Arguments:
packageversion display the package version
gemdir display the path where gems are installed
gempath display path used to search for gems
version display the gem format version
remotesources display the remote gem servers
platform display the supported gem platforms
<omitted> display everything
Summary:
Display information about the RubyGems environment
Description:
The RubyGems environment can be controlled through command line arguments,
gemrc files, environment variables and built-in defaults.
Command line argument defaults and some RubyGems defaults can be set in a
~/.gemrc file for individual users and a /etc/gemrc for all users. These
files are YAML files with the following YAML keys:
:sources: A YAML array of remote gem repositories to install gems from
:verbose: Verbosity of the gem command. false, true, and :really are the
levels
:update_sources: Enable/disable automatic updating of repository metadata
:backtrace: Print backtrace when RubyGems encounters an error
:gempath: The paths in which to look for gems
:disable_default_gem_server: Force specification of gem server host on
push
<gem_command>: A string containing arguments for the specified gem command
Example:
:verbose: false
install: --no-wrappers
update: --no-wrappers
:disable_default_gem_server: true
RubyGems' default local repository can be overridden with the GEM_PATH and
GEM_HOME environment variables. GEM_HOME sets the default repository to
install into. GEM_PATH allows multiple local repositories to be searched for
gems.
If you are behind a proxy server, RubyGems uses the HTTP_PROXY,
HTTP_PROXY_USER and HTTP_PROXY_PASS environment variables to discover the
proxy server.
If you would like to push gems to a private gem server the RUBYGEMS_HOST
environment variable can be set to the URI for that server.
If you are packaging RubyGems all of RubyGems' defaults are in
lib/rubygems/defaults.rb. You may override these in
lib/rubygems/defaults/operating_system.rb
kirti@kirti-Aspire-5733Z:~$ 最后，向您展示您的要求，我会做：
kirti@kirti-Aspire-5733Z:~$ gem environment gemdir
/home/kirti/.rvm/gems/ruby-2.0.0-p0
kirti@kirti-Aspire-5733Z:~$ gem environment gempath
/home/kirti/.rvm/gems/ruby-2.0.0-p0:/home/kirti/.rvm/gems/ruby-2.0.0-p0@global
kirti@kirti-Aspire-5733Z:~$ gem help commands。我应该写我正在使用rbenv。
您可以欺骗gem open显示宝石路径：
VISUAL=echo gem open gem-name例：
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它可以正常工作，并且不需要第三方gem。
-e选项（-e echo）指定“编辑器” 。
gem env就像gem environment。保存一些打字。
# 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/gem help commands返回“ 命令可以缩写，只要它们是模棱两可的。例如'gem i rake'是'gem install rake'的缩写。 ”换句话说gem environment，，gem env并且gem e所有工作gem environment都是自文档的，对于那些不知道的人它在做什么，因此我们应该将其用于初学者。
该gem env名单，其中的宝石可以进行安装，但是这可能是10点或更多的位置。如果您想知道特定gem 的安装位置，可以执行：
gem list -d <gemname>输出示例：
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
GEM PATHS只使用了第一个。那正确吗？