Building a Port Scanner CLI Tool in Go

Command-line tools are the backbone of network administration and security testing, and building your own port scanner is a fundamental step in mastering network programming. This text-based course guides you through the process of writing a fast, reliable port scanning CLI application using Go. You will transition from understanding basic networking concepts to writing a fully functional command-line utility. By exploring Go's powerful concurrency primitives and network packages, you will learn how to probe network ports safely, manage timeouts, and structure your CLI for optimal performance and readability. What you'll learn: - Understand foundational network concepts, TCP handshakes, and port states - Implement robust network timeout handling using Go's standard net package - Build a concurrent port scanner utilizing goroutines and channels for high-speed scanning - Create custom Go types and command-line flags to handle user inputs cleanly - Apply modern Go concurrency patterns, including Context for graceful cancellation - Practice structured error handling and format scanning results for CLI output The course begins with essential networking terminology and basic TCP connections before guiding you step-by-step through writing, optimizing, and testing your CLI tool. You will read clear explanations, analyze practical code snippets, and complete written exercises to solidify your understanding. This course is designed for beginner Go developers, system administrators, and aspiring security enthusiasts who want to learn network programming. No prior network scanning experience is required, though a basic familiarity with Go syntax is helpful. Start building your own network tools and master Go CLI development today.