C# on Ubuntu Linux: A Comprehensive 7-Day Guide

Beginner Friendly

C# has evolved from a Windows-centric language to a truly cross-platform powerhouse. With the advent of .NET Core and its evolution into the unified .NET platform, C# development on Linux has become not just possible, but a first-class experience. This comprehensive guide will take you through setting up a C# development environment on Linux and guide you through a 7-day learning journey to become proficient in C# development.

Introduction to C# and .NET on Linux

C# (pronounced "C-sharp") is a modern, object-oriented programming language developed by Microsoft. Initially released in 2000 as part of the .NET Framework, C# was primarily a Windows-centric language. However, with the introduction of .NET Core in 2016 and its evolution into the unified .NET platform, C# has become a truly cross-platform language that runs excellently on Linux.

By 2025, we're working with .NET 10, which represents a significant evolution in the platform's capabilities, particularly for Linux development. The modern .NET is:

• Open Source: The entire .NET platform is open source, with active community contributions.
• Cross-Platform: Runs on Windows, Linux, macOS, and more.
• High-Performance: Offers excellent performance, often comparable to or better than other compiled languages.
• Modern: Supports the latest programming paradigms and patterns.
• Versatile: Can be used for web, mobile, desktop, cloud, gaming, IoT, and more.

C# on Linux offers several advantages:

• Cost-Effective: Linux is free and open-source, reducing infrastructure costs.
• Performance: Linux's lightweight nature can provide performance benefits for server applications.
• Containerization: Excellent Docker and Kubernetes support for cloud-native development.
• Integration: Better integration with other open-source technologies commonly used in Linux environments.
• Flexibility: Freedom to choose your preferred Linux distribution and tools.

Day 1: Environment Setup and First Steps

Setting up .NET on Linux

The first step in your C# journey on Linux is to install the .NET SDK (Software Development Kit). The installation process varies slightly depending on your Linux distribution.

# Add Microsoft package repository
wget https://packages.microsoft.com/config/ubuntu/$(lsb_release -rs)/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo dpkg -i packages-microsoft-prod.deb
rm packages-microsoft-prod.deb

# Install .NET SDK
sudo apt-get update
sudo apt-get install -y apt-transport-https
sudo apt-get update
sudo apt-get install -y dotnet-sdk-10.0

# Verify installation
dotnet --version

# Add Microsoft package repository
sudo rpm -Uvh https://packages.microsoft.com/config/rhel/9/packages-microsoft-prod.rpm

# Install .NET SDK
sudo dnf install dotnet-sdk-10.0

# Verify installation
dotnet --version

# Install from official repositories
sudo pacman -S dotnet-sdk

# Verify installation
dotnet --version

# Add Microsoft package repository
sudo zypper install dotnet-sdk-10.0

# Verify installation
dotnet --version

After installation, verify that .NET is correctly installed by running:

dotnet --info

This command should display information about the installed .NET SDK, including the version number, installation location, and available runtimes.

Development Tools

While you can develop C# applications using just a text editor and the command line, using an Integrated Development Environment (IDE) or a powerful code editor can significantly enhance your productivity. Here are the recommended options for Linux:

Visual Studio Code

Visual Studio Code (VS Code) is a lightweight, open-source code editor that works excellently on Linux and provides rich support for C# development when configured with the right extensions.

Installation:

# Debian/Ubuntu
sudo apt-get install wget gpg
wget -qO- https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > packages.microsoft.gpg
sudo install -D -o root -g root -m 644 packages.microsoft.gpg /etc/apt/keyrings/packages.microsoft.gpg
sudo sh -c 'echo "deb [arch=amd64,arm64,armhf signed-by=/etc/apt/keyrings/packages.microsoft.gpg] https://packages.microsoft.com/repos/code stable main" > /etc/apt/sources.list.d/vscode.list'
rm -f packages.microsoft.gpg
sudo apt update
sudo apt install code

# Fedora/RHEL
sudo rpm --import https://packages.microsoft.com/keys/microsoft.asc
sudo sh -c 'echo -e "[code]\nname=Visual Studio Code\nbaseurl=https://packages.microsoft.com/yumrepos/vscode\nenabled=1\ngpgcheck=1\ngpgkey=https://packages.microsoft.com/keys/microsoft.asc" > /etc/yum.repos.d/vscode.repo'
sudo dnf install code

# Arch Linux
sudo pacman -S visual-studio-code-bin

Essential extensions for C# development:

• C# Dev Kit - Comprehensive C# development support
• .NET Core Tools - Tools for working with .NET projects
• NuGet Package Manager - Manage NuGet packages
• REST Client - Test APIs directly from VS Code
• Docker - Docker integration for containerized development

JetBrains Rider

JetBrains Rider is a full-featured, cross-platform .NET IDE. While it's not free, it offers a comprehensive development experience with advanced features.

Installation:

# Download and install from JetBrains website
wget https://download.jetbrains.com/rider/JetBrains.Rider-2025.1.0.tar.gz
sudo tar -xzf JetBrains.Rider-2025.1.0.tar.gz -C /opt
/opt/JetBrains.Rider-2025.1.0/bin/rider.sh

Command Line Tools

The .NET SDK comes with a powerful command-line interface (CLI) that allows you to create, build, test, and publish .NET applications. Here are some essential commands:

# Create a new console application
dotnet new console -n MyFirstApp

# Navigate to the project directory
cd MyFirstApp

# Build the application
dotnet build

# Run the application
dotnet run

# Publish the application
dotnet publish -c Release

Your First C# Program

Let's create your first C# program on Linux. We'll create a simple "Hello, World!" application to verify that everything is set up correctly.

1. Open a terminal and create a new directory for your project:

   mkdir HelloCSharp
   cd HelloCSharp

2. Create a new console application:

   dotnet new console

3. Open the generated Program.cs file in your preferred editor:

   code Program.cs  # If using VS Code

4. You'll see code similar to this (in C# 14):

   // Program.cs
   Console.WriteLine("Hello, World!");

5. Let's modify it slightly to make it more interactive:

   // Program.cs
   Console.WriteLine("Welcome to C# development on Linux!");
   Console.Write("Please enter your name: ");
   string? name = Console.ReadLine();
   Console.WriteLine($"Hello, {name}! Today is {DateTime.Now:d} and the time is {DateTime.Now:t}.");
   Console.WriteLine("You're running .NET on Linux successfully!");

6. Save the file and run the application:

   dotnet run

If everything is set up correctly, you should see the welcome message, be prompted to enter your name, and then see a personalized greeting with the current date and time.

Understanding the Project Structure

Let's take a moment to understand the structure of the project we just created:

HelloCSharp/
├── HelloCSharp.csproj  # Project file containing configuration
├── Program.cs          # Main source code file
├── obj/                # Directory for intermediate build files
└── bin/                # Directory for compiled output

The .csproj file is an XML file that contains project configuration, including target framework, dependencies, and build settings. The Program.cs file contains the actual C# code.

Day 1 Exercise: Enhancing Your First Application

To practice what you've learned, try enhancing your first application with the following features:

1. Ask the user for their favorite programming language
2. If they answer "C#", respond with an enthusiastic message
3. Otherwise, respond with a message encouraging them to give C# a try
4. Add a loop that allows the user to repeat the interaction or exit

Resources and References

Here are some valuable resources to supplement your learning:

Official Documentation

• Microsoft .NET Documentation
• .NET GitHub Repository
• C# Documentation

Community Resources

• Stack Overflow - C# Questions
• Reddit r/csharp
• Reddit r/dotnet
• .NET Foundation

Books and Courses

• "Pro C# 10 with .NET 10" by Andrew Troelsen and Phil Japikse
• "C# in Depth" by Jon Skeet
• "ASP.NET Core in Action" by Andrew Lock
• Pluralsight courses on C# and .NET
• Udemy courses on C# development

Remember, becoming proficient in C# and .NET development takes time and practice. This 7-day guide is just the beginning of your journey. Continue exploring, building, and learning to become a skilled C# developer on Linux!