Gem installation with gem install in Ruby

Introduction

We use gem install to add new tools or libraries to Ruby. These tools help us write programs faster and easier.

You want to add a new feature to your Ruby program, like working with web pages or databases.

You need to use code someone else wrote to save time.

You want to try out a new Ruby library you found online.

You are setting up a new Ruby project and need extra tools.

You want to update or install a specific version of a Ruby gem.

Syntax

Ruby

gem install gem_name [options]

Replace gem_name with the name of the gem you want to install.

You can add options like --version to install a specific version.

Examples

Installs the latest version of the rails gem.

Ruby

gem install rails

Installs version 1.13.3 of the nokogiri gem.

Ruby

gem install nokogiri --version 1.13.3

Installs the bundler gem, which helps manage other gems.

Ruby

gem install bundler

Sample Program

This example shows how to install the colorize gem and then use it to print blue text in Ruby.

Ruby

# This is a command line example, not a Ruby script
# Open your terminal or command prompt and type:
gem install colorize

# After installation, you can use the gem in your Ruby code like this:
require 'colorize'

puts 'Hello, world!'.colorize(:blue)

Important Notes

You need an internet connection to download gems.

Sometimes you may need to run gem install with sudo on Linux or macOS to get permission.

After installing a gem, you can use require 'gem_name' in your Ruby code to use it.

Summary

gem install adds new Ruby libraries to your system.

You run it in the terminal, not inside Ruby code.

Use require in Ruby to start using the installed gem.