For several consecutive years, Rust has been voted most loved programming language in Stack Overflow’s annual developer survey. This open source systems programming language is now used for everything from game engines and operating systems to browser components and virtual reality simulation engines. But Rust is also an incredibly complex language with a notoriously difficult learning curve. Rather than focus on the language as a whole, this guide teaches Rust using a single small, complete, focused program in each chapter. Author Ken Youens-Clark shows you how to start, write, and test each of these programs to create a finished product. You’ll learn how to handle errors in Rust, read and write files, and use regular expressions, Rust types, structs, and more. Discover how to: * Use Rust’s standard libraries and data types such as strings, vectors, dictionaries, and sets to create systems programs * Write and test Rust programs and functions * Read and write files, including stdin, stdout, and stderr * Document and validate command-line arguments * Write programs that fail gracefully * Parse raw and delimited text * Use and control randomness This book is a great way to practice writing Rust in real-world scenarios. Ken has laid out a path to build your skills in testing, using crates, and solving common problems. — Carol Nichols, Cofounder, Integer 32, co-author of *The Rust Programming Language* (NoStarch, 2018) Many people who start tinkering with Rust struggle to know how to apply it to their day-to-day work. *Command Line Rust* is an excellent remedy to this. It shows you how to build utilities that can demonstrate to you and your colleagues that Rust is worth learning. — Tim McNamara, author of *Rust In Action* (Manning, 2021)