# Ordú

Another command-line interface library for Ruby. This one is based entirely on
the venerable and built-in `OptionParser` class.

[![Build Status](https://travis-ci.org/bjjb/ordu.svg?branch=master)](https://travis-ci.org/bjjb/ordu)

## Installation

Add this line to your application's Gemfile:

```ruby
gem 'ordu'
```

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install ordu

## Usage

Write a subclass of `Ordu`. Then use the `option`, `command` and `action` to
define behaviour. In the background, a set of command-line parsers will be
built up. Now, calling the `parse!` method on the class itself, and passing in
an array of arguments will give you your CLI.

Here's a simple example:

```ruby
#!/usr/bin/env ruby
require 'ordu'
class Sneezer < Ordu
  # Define options much as you would with Ruby's built-in OptionParser. The
  # difference is that blocks are evaluated within the Ordu instance's
  # context.
  option('-h', '--help', 'print this message') { puts(self); exit }
  option('-V', '--version', 'print the version') { puts('0.0.1'); exit }
  option('-v', '--[no-]verbose', 'be noisy') { |v| $verbose = v }
  
  # Define an action to be run after commands are processed. This is optional.
  action do |*args|
    puts "Leftover args: #{args}" if $verbose
  end

  # Define one or more subcommands (with a brief description). They will be
  # turned into Ordu parsers, and given the remaining arguments to parse. The
  # DSL within a command is exactly like that of the top-level class.
  command 'sneeze', 'sneeze on the console' do
    option('-h', '--help', 'you are reading it') { puts(self); exit }
    option('-l', '--loud', 'sneeze louder') { @loud = true }
    option('-t', '--times N', Integer, 'sneeze repeatedly') { |n| @times = n }

    action do |*args|
      (@times || 1).times { puts 'Achoo!'.tap { |s| s.upcase! if @loud } }
      puts "After sneezing: #{args}" if $verbose
    end
  end
end

Sneezer.parse!(ARGV) # Processes the commands
```

This gives you a useless little tool which sneezed multiple times on demand.
You can see it in action if you're in this project's directory, and you run

    examples/sneezer.rb -h
    examples/sneezer.rb sneeze -h

These commands print out the Ordús, and thence the options and available
commands.

## Development

After checking out the repo, run `bin/setup` to install dependencies. Then,
run `rake test` to run the tests. You can also run `bin/console` for an
interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run `bundle exec rake install`.
To release a new version, update the version number in `ordu.gemspec`, and
then run `bundle exec rake release`, which will create a git tag for the
version, push git commits and tags, and push the `.gem` file to
[rubygems.org](https://rubygems.org).

## Contributing

Bug reports and pull requests are welcome on GitHub at
https://github.com/bjjb/ordu. This project is intended to be a safe, welcoming
space for collaboration, and contributors are expected to adhere to the
[Contributor Covenant](http://contributor-covenant.org) code of conduct.

## License

The gem is available as open source under the terms of the [MIT
License](http://opensource.org/licenses/MIT).