Slop is a simple option parser with an easy to remember syntax and friendly API.

This README is targeted at Slop v3.

gem install slop

git clone git://github.com/injekt/slop.git
gem build slop.gemspec
gem install slop-<version>.gem

# parse assumes ARGV, otherwise you can pass it your own Array
opts = Slop.parse do
  banner "ruby foo.rb [options]\n"
  on :name=, 'Your name'
  on :p, :password, 'Your password', :argument => :optional
  on :v, :verbose, 'Enable verbose mode'
end

# if ARGV is `--name Lee -v`
opts.verbose?  #=> true
opts.password? #=> false
opts[:name]    #=> 'lee'

Slop supports several methods of writing options:

# These options all do the same thing
on '-n', '--name', 'Your name', :argument => true
on 'n', :name=, 'Your name'
on :n, '--name=', 'Your name'

# As do these
on 'p', '--password', 'Your password', :argument => :optional
on :p, :password, 'Your password', :optional_argument => true
on '-p', 'password=?', 'Your password'

You can also return your options as a Hash:

opts.to_hash #=> { :name => 'lee', :verbose => true, :password => nil }

Slop attempts to build a good looking help string to print to your users. You can see this by calling opts.help or simply puts opts.

All of these options can be sent to Slop.new or Slop.parse in Hash form.

• strict - Enable strict mode. When processing unknown options, Slop will raise an InvalidOptionError. default: false.
• help - Automatically add the --help option. default: false.
• banner - Set this options banner text. default: nil.
• ignore_case - When enabled, -A will look for the -a option if -A does not exist. default: false.
• autocreate - Autocreate options on the fly. default: false.
• arguments - Force all options to expect arguments. default: false.
• optional_arguments - Force all options to accept optional arguments. default: false.
• multiple_switches - When disabled, Slop will parse -abc as the option a with the argument bc rather than 3 separate options. default: true.
• longest_flag - The longest string flag, used to aid configuring help text. default: 0.

Check out the following wiki pages for more features:

• Ranges
• Auto Create

I'm not, honestly! I love OptionParser. I really do, it's a fantastic library. So why did I build Slop? Well, I find myself using OptionParser to simply gather a bunch of key/value options, usually you would do something like this:

require 'optparse'

things = {}

opt = OptionParser.new do |opt|
  opt.on('-n', '--name NAME', 'Your name') do |name|
    things[:name] = name
  end

  opt.on('-a', '--age AGE', 'Your age') do |age|
    things[:age] = age.to_i
  end

  # you get the point
end

opt.parse
things #=> { :name => 'lee', :age => 105 }

Which is all great and stuff, but it can lead to some repetition. The same thing in Slop:

require 'slop'

opts = Slop.parse do
  on :n, :name=, 'Your name'
  on :a, :age=, 'Your age', :as => :int
end

opts.to_hash #=> { :name => 'lee', :age => 105 }