OptionParser

OptionParser is a class for command-line option analysis. It is much more advanced, yet also easier to use, than GetoptLong, and is a more Ruby-oriented solution.

1. The argument specification and the code to handle it are written in the same place.
2. It can output an option summary; you don't need to maintain this string separately.
3. Optional and mandatory arguments are specified very gracefully.
4. Arguments can be automatically converted to a specified class.
5. Arguments can be restricted to a certain set.

Add this line to your application's Gemfile:

gem 'optparse'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install optparse

require 'optparse'

options = {}
OptionParser.new do |opts|
  opts.banner = "Usage: example.rb [options]"

  opts.on("-v", "--[no-]verbose", "Run verbosely") do |v|
    options[:verbose] = v
  end
end.parse!

p options
p ARGV

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 version.rb, 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.

Bug reports and pull requests are welcome on GitHub at https://github.com/ruby/optparse.