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How to install or uninstall a gem in Ruby

How to install or uninstall a gem in Ruby ?


When you start with Ruby or Ruby on Rails development, first thing that you will start-up with is Installing Gems on your machine. In Ruby, you have to install a gem so that you can use the readily available, implemented code for your purpose.
How to Install a gem:

You can install gem using gem command. Example of using gem command:

gem install rake

This will install gem 'rake' on your machine.
While installing a gem you can also specify, which version of gem you have to install.
Install Specific Version of Gem:

gem install rake -v 0.8.7

After your gem is installed on your machine, it also install the documentation for the gem that you have installed. You can view the documentation for your installed gem with command:
View Documentation of the Gem :

ri rake

Search the gem with name:

You can search for available gems by the name using command like,

gem search ^rake

It will search for the gem's having name starting with 'rake'. Regular expression can be used to search the name in above command as used in above command example.
List Available gems on your machine:

gem list

This command lists all the available gems on your machine. If you want to see the version number of specific gem that you have installed then this command is very helpful for you.
Uninstall a specific gem:

gem uninstall rake

This will uninstall the gem named 'rake' from your machine. If the gem that you are trying to uninstall has dependency on some other gem, then it will ask whether it should the gem has it has a dependency on some other gem.

These are the basic gem operations with command line examples. You  can go for more if you need more of these.

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