command_kit

Description

A Ruby toolkit for building clean, correct, and robust CLI commands as plain-old Ruby classes.

Features

Anti-Features

Requirements

Install

$ gem install command_kit

gemspec

gem.add_dependency 'command_kit', '~> 0.2'

Gemfile

gem 'command_kit', '~> 0.2'

Examples

lib/foo/cli/my_cmd.rb

require 'command_kit'

module Foo
  module CLI
    class MyCmd < CommandKit::Command

      usage '[OPTIONS] [-o OUTPUT] FILE'

      option :count, short: '-c',
                     value: {
                       type: Integer,
                       default: 1
                     },
                     desc: "Number of times"

      option :output, short: '-o',
                      value: {
                        type: String,
                        usage: 'FILE'
                      },
                      desc: "Optional output file"

      option :verbose, short: '-v', desc: "Increase verbose level" do
        @verbose += 1
      end

      argument :file, required: true,
                      usage: 'FILE',
                      desc: "Input file"

      examples [
        '-o path/to/output.txt path/to/input.txt',
        '-v -c 2 -o path/to/output.txt path/to/input.txt',
      ]

      description 'Example command'

      def initialize(**kwargs)
        super(**kwargs)

        @verbose = 0
      end

      def run(file)
        puts "count=#{options[:count].inspect}"
        puts "output=#{options[:output].inspect}"
        puts "file=#{file.inspect}"
        puts "verbose=#{@verbose.inspect}"
      end

    end
  end
end

bin/my_cmd

#!/usr/bin/env ruby

$LOAD_PATH.unshift(File.expand_path('../../lib',__FILE__))
require 'foo/cli/my_cmd'

Foo::CLI::MyCmd.start

–help

Usage: my_cmd [OPTIONS] [-o OUTPUT] FILE

Options:
    -c, --count INT                  Number of times (Default: 1)
    -o, --output FILE                Optional output file
    -v, --verbose                    Increase verbose level
    -h, --help                       Print help information

Arguments:
    FILE                             Input file

Examples:
    my_cmd -o path/to/output.txt path/to/input.txt
    my_cmd -v -c 2 -o path/to/output.txt path/to/input.txt

Example command

Reference

Alternatives

Special Thanks

Special thanks to everyone who answered my questions and gave feedback on Twitter.

Copyright © 2021 Hal Brodigan

See {file:LICENSE.txt} for details.