Vitte

9. CLI Mini Project

Level: beginner · Reading time: 3 min · Prerequisite: book/poche/08-essential-tests.html · Last review: 2026-05-09

TL;DR (5 lines)

  • Read the core idea first.
  • Understand one concept at a time.
  • Run small examples.
  • Fix errors early.
  • Move to next chapter only when clear.

Frequent mistakes

  • Skipping prerequisites.
  • Reading without trying examples.
  • Fixing too many errors at once.

Prerequisites: book/poche/08-essential-tests.html. See also: book/chapters/21-cli-project.html.

Goal

Assemble the basics into a concrete mini-project.

Example

Simple CLI: calc add 2 3 -> 5.

Why it matters

A short project quickly reveals areas that are still unclear.

Quick check

Which parts of the project fall under modules, types and errors?

Try this

  1. Read the arguments.
  2. Call a business procedure.
  3. Show result.

If you're stuck

Keep a single use case (add) before adding options.

Mini quiz

  1. What is the main goal of this chapter?
  2. Which concept is most important?
  3. What will you try right now?

See also

Next best action

Apply one idea from this chapter in a tiny example, then continue.