module Mixlib::CLI

Mixlib::CLI

Adds a DSL for defining command line options and methods for parsing those options to the including class.

Mixlib::CLI does some setup in initialize, so the including class must call ‘super()` if it defines a custom initializer.

DSL

When included, Mixlib::CLI also extends the including class with its ClassMethods, which define the DSL. The primary methods of the DSL are ClassMethods#option, which defines a command line option, and ClassMethods#banner, which defines the “usage” banner.

Parsing

Command line options are parsed by calling the instance method parse_options. After calling this method, the attribute config will contain a hash of ‘:option_name => value` pairs.

Constants

VERSION

Attributes

banner[RW]

Banner for the option parser. If the option parser is printed, e.g., by ‘puts opt_parser`, this string will be used as the first line.

cli_arguments[RW]

Any arguments which were not parsed and placed in “config”–the leftovers.

config[RW]

A Hash containing the values supplied by command line options.

The behavior and contents of this Hash vary depending on whether ClassMethods#use_separate_default_options is enabled.

use_separate_default_options disabled

After initialization, config will contain any default values defined via the mixlib-config DSL. When parse_options is called, user-supplied values (from ARGV) will be merged in.

use_separate_default_options enabled

After initialization, this will be an empty hash. When parse_options is called, config is populated only with user-supplied values.

default_config[RW]

If ClassMethods#use_separate_default_options is enabled, this will be a Hash containing key value pairs of ‘:option_name => default_value` (populated during object initialization).

If use_separate_default_options is disabled, it will always be an empty hash.

options[RW]

Gives the command line options definition as configured in the DSL. These are used by parse_options to generate the option parsing code. To get the values supplied by the user, see config.

Public Class Methods

included(receiver) click to toggle source
# File lib/mixlib/cli.rb, line 323
def self.included(receiver)
  receiver.extend(Mixlib::CLI::ClassMethods)
  receiver.extend(Mixlib::CLI::InheritMethods)
end
new(*args) click to toggle source

Create a new Mixlib::CLI class. If you override this, make sure you call super!

Parameters

*args<Array>

The array of arguments passed to the initializer

Returns

object<Mixlib::Config>

Returns an instance of whatever you wanted :)

Calls superclass method
# File lib/mixlib/cli.rb, line 183
def initialize(*args)
  @options = Hash.new
  @config  = Hash.new
  @default_config = Hash.new
  @opt_parser = nil

  # Set the banner
  @banner = self.class.banner

  # Dupe the class options for this instance
  klass_options = self.class.options
  klass_options.keys.inject(@options) { |memo, key| memo[key] = klass_options[key].dup; memo }

  # If use_separate_defaults? is on, default values go in @default_config
  defaults_container = if self.class.use_separate_defaults?
                         @default_config
                       else
                         @config
                       end

  # Set the default configuration values for this instance
  @options.each do |config_key, config_opts|
    config_opts[:on] ||= :on
    config_opts[:boolean] ||= false
    config_opts[:required] ||= false
    config_opts[:proc] ||= nil
    config_opts[:show_options] ||= false
    config_opts[:exit] ||= nil
    config_opts[:in] ||= nil

    if config_opts.has_key?(:default)
      defaults_container[config_key] = config_opts[:default]
    end
  end

  super(*args)
end

Public Instance Methods

build_option_arguments(opt_setting) click to toggle source
# File lib/mixlib/cli.rb, line 308
def build_option_arguments(opt_setting)
  arguments = Array.new

  arguments << opt_setting[:short] if opt_setting.has_key?(:short)
  arguments << opt_setting[:long] if opt_setting.has_key?(:long)
  if opt_setting.has_key?(:description)
    description = opt_setting[:description]
    description << " (required)" if opt_setting[:required]
    description << " (included in ['#{opt_setting[:in].join("', '")}'])" if opt_setting[:in]
    arguments << description
  end

  arguments
end
opt_parser() click to toggle source

The option parser generated from the mixlib-cli DSL. opt_parser can be used to print a help message including the banner and any CLI options via ‘puts opt_parser`.

Returns

opt_parser<OptionParser>

The option parser object.

# File lib/mixlib/cli.rb, line 262
def opt_parser
  @opt_parser ||= OptionParser.new do |opts|
    # Set the banner
    opts.banner = banner

    # Create new options
    options.sort { |a, b| a[0].to_s <=> b[0].to_s }.each do |opt_key, opt_val|
      opt_args = build_option_arguments(opt_val)

      opt_method = case opt_val[:on]
                   when :on
                     :on
                   when :tail
                     :on_tail
                   when :head
                     :on_head
                   else
                     raise ArgumentError, "You must pass :on, :tail, or :head to :on"
                   end

      parse_block =
        Proc.new() do |c|
          config[opt_key] = if opt_val[:proc]
                              if opt_val[:proc].arity == 2
                                # New hotness to allow for reducer-style procs.
                                opt_val[:proc].call(c, config[opt_key])
                              else
                                # Older single-argument proc.
                                opt_val[:proc].call(c)
                              end
                            else
                              # No proc.
                              c
                            end
          puts opts if opt_val[:show_options]
          exit opt_val[:exit] if opt_val[:exit]
        end

      full_opt = [ opt_method ]
      opt_args.inject(full_opt) { |memo, arg| memo << arg; memo }
      full_opt << parse_block
      opts.send(*full_opt)
    end
  end
end
parse_options(argv = ARGV) click to toggle source

Parses an array, by default ARGV, for command line options (as configured at the class level).

Parameters

argv<Array>

The array of arguments to parse; defaults to ARGV

Returns

argv<Array>

Returns any un-parsed elements.

# File lib/mixlib/cli.rb, line 228
def parse_options(argv = ARGV)
  argv = argv.dup
  opt_parser.parse!(argv)

  # Deal with any required values
  options.each do |opt_key, opt_value|
    if opt_value[:required] && !config.has_key?(opt_key)
      reqarg = opt_value[:short] || opt_value[:long]
      puts "You must supply #{reqarg}!"
      puts @opt_parser
      exit 2
    end
    if opt_value[:in]
      unless opt_value[:in].kind_of?(Array)
        raise(ArgumentError, "Options config key :in must receive an Array")
      end
      if !opt_value[:in].include?(config[opt_key])
        reqarg = opt_value[:short] || opt_value[:long]
        puts "#{reqarg}: #{config[opt_key]} is not included in the list ['#{opt_value[:in].join("', '")}'] "
        puts @opt_parser
        exit 2
      end
    end
  end

  @cli_arguments = argv
  argv
end