Welcome to the Ruby CLI Tutorial! This guide will help you learn how to use the Ruby programming language to create command-line tools and scripts. Whether you're a beginner or an experienced programmer, this tutorial will provide you with the knowledge to get started.

Table of Contents

Introduction

Command-line interfaces (CLI) are powerful tools for automating tasks and managing your system. Ruby, being a versatile programming language, excels in CLI development. In this tutorial, we'll explore the basics of Ruby CLI programming and delve into more advanced topics.

Setting Up Your Environment

Before you start, make sure you have Ruby installed on your system. You can check if Ruby is installed by running the following command in your terminal:

ruby -v

If Ruby is not installed, you can download and install it from the official Ruby website.

Basic Commands

Ruby CLI tools often start with a ruby command followed by the name of the script file. Here's an example of a simple Ruby CLI script:

# hello.rb

puts "Hello, World!"

To run this script, save it as hello.rb and execute the following command in your terminal:

ruby hello.rb

You should see "Hello, World!" printed to your terminal.

Scripting with Ruby

Ruby scripts can be used to automate various tasks. Here's an example of a script that counts the number of lines in a file:

# count_lines.rb

file_path = ARGV[0]

if file_path
  lines = File.readlines(file_path).count
  puts "The file #{file_path} has #{lines} lines."
else
  puts "Usage: ruby count_lines.rb <file_path>"
end

To use this script, save it as count_lines.rb and run it with the file path as an argument:

ruby count_lines.rb example.txt

Advanced Topics

As you become more comfortable with Ruby CLI programming, you can explore more advanced topics such as error handling, command-line options, and integrating with external tools.

For more information, check out our Advanced Ruby CLI Programming Guide.

Further Reading

Ruby