--The library for the Ruby language provided in a fixed format is called "gem". --For example, "gem" includes the following. --Rails (Web framework) --Sinatra (Web framework) --omniauth (authentication function) --unicorn (application server) --Rspec (test framework) ...etc --Corresponds to CPAN in Perl, pear in php, etc.
--A package management system dedicated to gems, similar to yum and apt. --The following site discloses and provides information on gems. https://rubygems.org/
--Gem can be manually installed individually as follows. - gem install "sinatra" - gem install "unicorn" - gem install "omniauth" ――However, when using various gems (libraries) in combination, there may be a compatibility problem such as "gemA ver1 and gemB ver2 work well, but the latest versions do not work well." There is. --In addition, when developing with multiple people and multiple environments, it is necessary to match the name and version of the library used in each environment. ――In such a case, Bundler will install and manage each gem while maintaining compatibility between gems. --Write the gem you want to install in a file called Gemfile, and install using bundler based on it. --Basically, it is recommended to install gems other than bundler via bundler.
--Installing Bundler --Bundler is also one of the gems. Let's download manually - gem install bundler --Check that the version is displayed after installation. - bundler -v
--Recommendation of Rubygems | For beginners who are not familiar with Ruby http://qiita.com/sumyapp/items/5ec58bf3567e557c24d7 --Bundler overview http://qiita.com/hisonl/items/162f70e612e8e96dba50 --What is Bundler? http://shokai.org/blog/archives/7262
Gem command and Bundler basics -BlueTechNote
$ gem install $ gem update $ gem uninstall
bundler --Install Bundler --Write the Gem to install in the Gemfile --Install with the bundle install command --Upgrade the Gem with the bundle update command
-Install Bundler (m ・_・ Bp) 17:50 ~/Desktop/vsnote2.0/ruby % gem install bundler Fetching bundler-2.1.4.gem Successfully installed bundler-2.1.4 Parsing documentation for bundler-2.1.4 Installing ri documentation for bundler-2.1.4 Done installing documentation for bundler after 2 seconds 1 gem installed -Write the Gem to install in the Gemfile (m ・_・ Bp) 17:51 ~/Desktop/vsnote2.0/ruby % bundle init Writing new Gemfile to /Users/uekiyoshihiro/Desktop/vsnote2.0/ruby/Gemfile -Install with the bundle install command (m ・_・ Bp) 17:53 ~/Desktop/vsnote2.0/ruby % bundle install Fetching gem metadata from https://rubygems.org/........... Resolving dependencies... Using bundler 2.1.4 Fetching coderay 1.1.2 Installing coderay 1.1.2 Fetching method_source 1.0.0 Installing method_source 1.0.0 Fetching pry 0.13.1 Installing pry 0.13.1 Bundle complete! 1 Gemfile dependency, 4 gems now installed. Use `bundle info [gemname]` to see where a bundled gem is installed. -Upgrade Gem with the bundle update command (m ・_・ Bp) 17:58 ~/Desktop/vsnote2.0/ruby % bundle update Fetching gem metadata from https://rubygems.org/........... Resolving dependencies... Using bundler 2.1.4 Using coderay 1.1.2 Using method_source 1.0.0 Using pry 0.13.1 Bundle updated!
$ bundle init #Generate Gemfile $ bundle install #Install the gem package written in the Gemfile $ bundle exec #Run the command using the gem package installed with Bundler $ bundle list #View a list of installed gem packages $ bundle update #Update installed gem package version