Building a CLI Tool in Rust

I recently finished rewriting one of my Python CLI tools in Rust. The goal wasn’t speed (though that was a nice side effect) — it was learning the language properly.

Why Rust for CLIs?

Rust is an excellent choice for command-line tools:

• Single binary — No runtime dependencies, easy to distribute.
• Excellent error handling — The Result type forces you to handle errors explicitly.
• Crates like clap — Makes argument parsing a breeze with derive macros.

What I Learned

The borrow checker was predictably frustrating at first, but once it clicked, I started writing safer code by default. The compiler catches issues that would be runtime bugs in Python or JavaScript.

Performance

The final binary is about 3MB (stripped) and processes log files roughly 15x faster than the Python equivalent. For a tool that parses multi-gigabyte log files, that difference matters.