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A Ruby gem is a library you can use in your Ruby applications. It's really easy to install a gem. You just need to know the name of the gem you want to install. In this Treehouse Quick Tip, Ruby teacher Jason shows you how to install the Bundler gem.
[treehouse presents] 0:00 [Quick Tips] [How to Install Gems in Ruby on Rails] [by Jason Seifer] 0:03 Hi, I'm Jason. 0:06 In this treehouse quick tip, we're going to talk about how to install Ruby gems. 0:07 A Ruby gem is a library that you can use in your Ruby applications. 0:11 It's really easy to install a gem. 0:15 You just need to know the name of the gem that you want to install. 0:18 In this example, I'm going to install the Bundler gem. 0:21 The way to install a gem is by typing the word "gem" followed by a space 0:25 followed by the word "install" and then the name of the gem that you want to install. 0:31 I'm going to install the Bundler gem. 0:36 After that, press "enter" and then Ruby gems will go out, download the proper gem, 0:38 and install it onto your system. 0:43 If you get a message about not having the proper permissions to install a gem, 0:45 you can use the "sudo" command to install the correct gem. 0:50 You would use the "sudo" command on systems where your version of Ruby is installed 0:54 globally rather than on a system like RVM or RBN where you can install gems locally 1:00 to your own home directory. 1:06 I'm going to install another gem called Money. 1:08 The gem install command will also install any needed dependencies of a gem. 1:14 For example, the Money gem requires the i18n gem and also the json gems. 1:18 Once you install a gem, it's really easy to use. 1:24 First, require Ruby gems, then you can also require the gem that you just installed. 1:27 And there you go. 1:36 There's one other way to install gems, and that would be from a gem file. 1:37 A gem file will be in a Ruby on Rails application or actually any Ruby application 1:42 that uses Bundler. 1:48 You specify the gem dependencies in the gem file, and then once you do that, 1:49 you can type the word "bundle install" and then Bundler will go through and install 1:54 all of these gems for you. 2:01 As you can see, it's very easy to install and use Ruby gems. 2:09 The hardest part is finding good ones to install. 2:12 Luckily, there are sites like RubyGems.org and GitHub for that. 2:15 Happy coding! 2:19
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