david-wallace-croft / commander

Rust command-line arguments parser

CroftSoft Commander

Purpose

• A command-line arguments parser library
  • An alternative to using the Command Line Argument Parser (clap) for Rust

History

• My first open source Rust program
• Started off as an example of a Rust-based command-line program
  • To be copied as a template to start new projects
  • The project originally used clap to parse the command-line arguments
• Morphed into a parser library instead
  • I decided I should learn how to parse command-line arguments myself
  • As part of my learning the basics of the Rust programming language

Usage

Parser Library Example

• cargo run --example example-commander -- --help
  • Prints the help information for the examples that uses the library
• cargo run --example example-commander
  • Runs the example that uses the library
• cargo run --example example-commander -- -i=false
  • Disable interactive mode
• cargo run --example example-commander -- -n=World
  • Provide the default name
• cargo run --example example-commander -- -i=false -n=World
  • Disable interactive mode and use the specified name
• cargo run --example example-commander -- --interactive=false
  • Disable interactive mode
• cargo run --example example-commander -- --name=World
  • Provide the default name
• cargo run --example example-commander -- -u
  • Show an error message for the unrecognized option
• cargo run --example example-commander -- --unrecognized
  • Show an error message for the unrecognized option
• cargo run --example example-commander -- --help=true
  • Show an error message for an invalid option value

clap Example

• Usage for the clap Example is similar to the Parser Library Example
  • Except that the commands start with "cargo run --example example-clap"

Project Structure

• A Rust workspace with two crates
• The primary library crate "croftsoft-commander"
  • Functions for parsing option values from command-line arguments
  • Functions for displaying application help information including options
• The secondary library crate "croftsoft-commander-examples"
  • With two example applications
    • One showing how to use the library crate "croftsoft-commander"
    • The other showing how to run the same example application using "clap"
  • And a library containing the application code common to the two examples
    • A "Hello, World" application that prompts the user for a name
    • Configured by parsing option values from command-line arguments
    • Using either the "croftsoft-commander" library or the "clap" library

Development Commands

• cargo clippy
• cargo doc --examples --no-deps
  • Makes target/doc/commander/index.html
• cargo fmt
• cargo test
• cargo test --all-targets
• cargo update
• rustup update

TODO

• Parse sub-commands
• Use a code coverage tool