OptionParser

`OptionParser`

Introduction

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.

Features

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

All of these features are demonstrated in the examples below. See make_switch for full documentation.

Minimal example

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

Generating Help

OptionParser can be used to automatically generate help for the commands you write:

require 'optparse'

Options = Struct.new(:name)

class Parser
  def self.parse(options)
    args = Options.new("world")

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

      opts.on("-nNAME", "--name=NAME", "Name to say hello to") do |n|
        args.name = n
      end

      opts.on("-h", "--help", "Prints this help") do
        puts opts
        exit
      end
    end

    opt_parser.parse!(options)
    return args
  end
end
options = Parser.parse %w[--help]

#=>
   # Usage: example.rb [options]
   #     -n, --name=NAME                  Name to say hello to
   #     -h, --help                       Prints this help

Required Arguments

For options that require an argument, option specification strings may include an option name in all caps. If an option is used without the required argument, an exception will be raised.

require 'optparse'

options = {}
OptionParser.new do |parser|
  parser.on("-r", "--require LIBRARY",
            "Require the LIBRARY before executing your script") do |lib|
    puts "You required #{lib}!"
  end
end.parse!

Used:

bash-3.2$ ruby optparse-test.rb -r
optparse-test.rb:9:in `<main>': missing argument: -r (OptionParser::MissingArgument)
bash-3.2$ ruby optparse-test.rb -r my-library
You required my-library!

Type Coercion

OptionParser supports the ability to coerce command line arguments into objects for us.

OptionParser comes with a few ready-to-use kinds of type coercion. They are:

Date – Anything accepted by Date.parse
DateTime – Anything accepted by DateTime.parse
Time – Anything accepted by Time.httpdate or Time.parse
URI – Anything accepted by URI.parse
Shellwords – Anything accepted by Shellwords.shellwords
String – Any non-empty string
Integer – Any integer. Will convert octal. (e.g. 124, -3, 040)
Float – Any float. (e.g. 10, 3.14, -100E+13)
Numeric – Any integer, float, or rational (1, 3.4, 1/3)
DecimalInteger – Like Integer, but no octal format.
OctalInteger – Like Integer, but no decimal format.
DecimalNumeric – Decimal integer or float.
TrueClass – Accepts ‘+, yes, true, -, no, false’ and defaults as true
FalseClass – Same as TrueClass, but defaults to false
Array – Strings separated by ‘,’ (e.g. 1,2,3)
Regexp – Regular expressions. Also includes options.

We can also add our own coercions, which we will cover soon.

Using Built-in Conversions

As an example, the built-in Time conversion is used. The other built-in conversions behave in the same way. OptionParser will attempt to parse the argument as a Time. If it succeeds, that time will be passed to the handler block. Otherwise, an exception will be raised.

require 'optparse'
require 'optparse/time'
OptionParser.new do |parser|
  parser.on("-t", "--time [TIME]", Time, "Begin execution at given time") do |time|
    p time
  end
end.parse!

Used:

bash-3.2$ ruby optparse-test.rb  -t nonsense
... invalid argument: -t nonsense (OptionParser::InvalidArgument)
from ... time.rb:5:in `block in <top (required)>'
from optparse-test.rb:31:in `<main>'
bash-3.2$ ruby optparse-test.rb  -t 10-11-12
2010-11-12 00:00:00 -0500
bash-3.2$ ruby optparse-test.rb  -t 9:30
2014-08-13 09:30:00 -0400

Creating Custom Conversions

The accept method on OptionParser may be used to create converters. It specifies which conversion block to call whenever a class is specified. The example below uses it to fetch a User object before the on handler receives it.

require 'optparse'

User = Struct.new(:id, :name)

def find_user id
  not_found = ->{ raise "No User Found for id #{id}" }
  [ User.new(1, "Sam"),
    User.new(2, "Gandalf") ].find(not_found) do |u|
    u.id == id
  end
end

op = OptionParser.new
op.accept(User) do |user_id|
  find_user user_id.to_i
end

op.on("--user ID", User) do |user|
  puts user
end

op.parse!

output:

bash-3.2$ ruby optparse-test.rb --user 1
#<struct User id=1, name="Sam">
bash-3.2$ ruby optparse-test.rb --user 2
#<struct User id=2, name="Gandalf">
bash-3.2$ ruby optparse-test.rb --user 3
optparse-test.rb:15:in `block in find_user': No User Found for id 3 (RuntimeError)

Complete example

The following example is a complete Ruby program. You can run it and see the effect of specifying various options. This is probably the best way to learn the features of optparse.

require 'optparse'
require 'optparse/time'
require 'ostruct'
require 'pp'

class OptparseExample
  Version = '1.0.0'

  CODES = %w[iso-2022-jp shift_jis euc-jp utf8 binary]
  CODE_ALIASES = { "jis" => "iso-2022-jp", "sjis" => "shift_jis" }

  class ScriptOptions
    attr_accessor :library, :inplace, :encoding, :transfer_type,
                  :verbose, :extension, :delay, :time, :record_separator,
                  :list

    def initialize
      self.library = []
      self.inplace = false
      self.encoding = "utf8"
      self.transfer_type = :auto
      self.verbose = false
    end

    def define_options(parser)
      parser.banner = "Usage: example.rb [options]"
      parser.separator ""
      parser.separator "Specific options:"

      # add additional options
      perform_inplace_option(parser)
      delay_execution_option(parser)
      execute_at_time_option(parser)
      specify_record_separator_option(parser)
      list_example_option(parser)
      specify_encoding_option(parser)
      optional_option_argument_with_keyword_completion_option(parser)
      boolean_verbose_option(parser)

      parser.separator ""
      parser.separator "Common options:"
      # No argument, shows at tail.  This will print an options summary.
      # Try it and see!
      parser.on_tail("-h", "--help", "Show this message") do
        puts parser
        exit
      end
      # Another typical switch to print the version.
      parser.on_tail("--version", "Show version") do
        puts Version
        exit
      end
    end

    def perform_inplace_option(parser)
      # Specifies an optional option argument
      parser.on("-i", "--inplace [EXTENSION]",
                "Edit ARGV files in place",
                "(make backup if EXTENSION supplied)") do |ext|
        self.inplace = true
        self.extension = ext || ''
        self.extension.sub!(/\A\.?(?=.)/, ".")  # Ensure extension begins with dot.
      end
    end

    def delay_execution_option(parser)
      # Cast 'delay' argument to a Float.
      parser.on("--delay N", Float, "Delay N seconds before executing") do |n|
        self.delay = n
      end
    end

    def execute_at_time_option(parser)
      # Cast 'time' argument to a Time object.
      parser.on("-t", "--time [TIME]", Time, "Begin execution at given time") do |time|
        self.time = time
      end
    end

    def specify_record_separator_option(parser)
      # Cast to octal integer.
      parser.on("-F", "--irs [OCTAL]", OptionParser::OctalInteger,
                "Specify record separator (default \\0)") do |rs|
        self.record_separator = rs
      end
    end

    def list_example_option(parser)
      # List of arguments.
      parser.on("--list x,y,z", Array, "Example 'list' of arguments") do |list|
        self.list = list
      end
    end

    def specify_encoding_option(parser)
      # Keyword completion.  We are specifying a specific set of arguments (CODES
      # and CODE_ALIASES - notice the latter is a Hash), and the user may provide
      # the shortest unambiguous text.
      code_list = (CODE_ALIASES.keys + CODES).join(', ')
      parser.on("--code CODE", CODES, CODE_ALIASES, "Select encoding",
                "(#{code_list})") do |encoding|
        self.encoding = encoding
      end
    end

    def optional_option_argument_with_keyword_completion_option(parser)
      # Optional '--type' option argument with keyword completion.
      parser.on("--type [TYPE]", [:text, :binary, :auto],
                "Select transfer type (text, binary, auto)") do |t|
        self.transfer_type = t
      end
    end

    def boolean_verbose_option(parser)
      # Boolean switch.
      parser.on("-v", "--[no-]verbose", "Run verbosely") do |v|
        self.verbose = v
      end
    end
  end

  #
  # Return a structure describing the options.
  #
  def parse(args)
    # The options specified on the command line will be collected in
    # *options*.

    @options = ScriptOptions.new
    @args = OptionParser.new do |parser|
      @options.define_options(parser)
      parser.parse!(args)
    end
    @options
  end

  attr_reader :parser, :options
end  # class OptparseExample

example = OptparseExample.new
options = example.parse(ARGV)
pp options # example.options
pp ARGV

`Shell` Completion

For modern shells (e.g. bash, zsh, etc.), you can use shell completion for command line options.

Further documentation

The above examples should be enough to learn how to use this class. If you have any questions, file a ticket at bugs.ruby-lang.org.

Constants

DecimalInteger

Decimal integer format, to be converted to Integer.

DecimalNumeric

Decimal integer/float number format, to be converted to Integer for integer format, Float for float format.

Write

Version

Class Methods

accept(*args, &blk)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1099
def self.accept(*args, &blk) top.accept(*args, &blk) end

See accept.

each_const(path, base = ::Object)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse/version.rb, line 50
def each_const(path, base = ::Object)
  path.split(/::|\//).inject(base) do |klass, name|
    raise NameError, path unless Module === klass
    klass.constants.grep(/#{name}/i) do |c|
      klass.const_defined?(c) or next
      klass.const_get(c)
    end
  end
end

No documentation available

getopts(*args)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1691
def self.getopts(*args)
  new.getopts(*args)
end

See getopts.

inc(arg, default = nil)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1035
def self.inc(arg, default = nil)
  case arg
  when Integer
    arg.nonzero?
  when nil
    default.to_i + 1
  end
end

Returns an incremented value of default according to arg.

new(banner = nil, width = 32, indent = ' ' * 4) { |self| ... }

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1054
def initialize(banner = nil, width = 32, indent = ' ' * 4)
  @stack = [DefaultList, List.new, List.new]
  @program_name = nil
  @banner = banner
  @summary_width = width
  @summary_indent = indent
  @default_argv = ARGV
  add_officious
  yield self if block_given?
end

Initializes the instance and yields itself if called with a block.

banner: Banner message.
width: Summary width.
indent: Summary indent.

reject(*args, &blk)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1112
def self.reject(*args, &blk) top.reject(*args, &blk) end

See reject.

search_const(klass, name) { |klass, cname, const| ... }

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            # File tmp/rubies/ruby-2.3.8/lib/optparse/version.rb, line 60
def search_const(klass, name)
  klasses = [klass]
  while klass = klasses.shift
    klass.constants.each do |cname|
      klass.const_defined?(cname) or next
      const = klass.const_get(cname)
      yield klass, cname, const if name === cname
      klasses << const if Module === const and const != ::Object
    end
  end
end

No documentation available

show_version(*pkgs)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse/version.rb, line 5
def show_version(*pkgs)
  progname = ARGV.options.program_name
  result = false
  show = proc do |klass, cname, version|
    str = "#{progname}"
    unless klass == ::Object and cname == :VERSION
      version = version.join(".") if Array === version
      str << ": #{klass}" unless klass == Object
      str << " version #{version}"
    end
    [:Release, :RELEASE].find do |rel|
      if klass.const_defined?(rel)
        str << " (#{klass.const_get(rel)})"
      end
    end
    puts str
    result = true
  end
  if pkgs.size == 1 and pkgs[0] == "all"
    self.search_const(::Object, /\AV(?:ERSION|ersion)\z/) do |klass, cname, version|
      unless cname[1] == ?e and klass.const_defined?(:Version)
        show.call(klass, cname.intern, version)
      end
    end
  else
    pkgs.each do |pkg|
      begin
        pkg = pkg.split(/::|\//).inject(::Object) {|m, c| m.const_get(c)}
        v = case
            when pkg.const_defined?(:Version)
              pkg.const_get(n = :Version)
            when pkg.const_defined?(:VERSION)
              pkg.const_get(n = :VERSION)
            else
              n = nil
              "unknown"
            end
        show.call(pkg, n, v)
      rescue NameError
      end
    end
  end
  result
end

No documentation available

terminate(arg = nil)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1079
def self.terminate(arg = nil)
  throw :terminate, arg
end

No documentation available

top

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1084
def self.top() DefaultList end

No documentation available

with(*args, &block)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1026
def self.with(*args, &block)
  opts = new(*args)
  opts.instance_eval(&block)
  opts
end

Initializes a new instance and evaluates the optional block in context of the instance. Arguments args are passed to new, see there for description of parameters.

This method is deprecated, its behavior corresponds to the older new method.

Instance Methods

abort(mesg = $!)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1193
def abort(mesg = $!)
  super("#{program_name}: #{mesg}")
end

No documentation available

accept(*args, &blk)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1095
def accept(*args, &blk) top.accept(*args, &blk) end

Directs to accept specified class t. The argument string is passed to the block in which it should be converted to the desired class.

t: Argument class specifier, any object including Class.
pat: Pattern for argument, defaults to t if it responds to match.

accept(t, pat, &block)

banner

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1137
def banner
  unless @banner
    @banner = "Usage: #{program_name} [options]"
    visit(:add_banner, @banner)
  end
  @banner
end

Heading banner preceding summary.

base

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1207
def base
  @stack[1]
end

Subject of on_tail.

candidate(word)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1738
def candidate(word)
  list = []
  case word
  when /\A--/
    word, arg = word.split(/=/, 2)
    argpat = Completion.regexp(arg, false) if arg and !arg.empty?
    long = true
  when /\A-(!-)/
    short = true
  when /\A-/
    long = short = true
  end
  pat = Completion.regexp(word, true)
  visit(:each_option) do |opt|
    next unless Switch === opt
    opts = (long ? opt.long : []) + (short ? opt.short : [])
    opts = Completion.candidate(word, true, pat, &opts.method(:each)).map(&:first) if pat
    if /\A=/ =~ opt.arg
      opts.map! {|sw| sw + "="}
      if arg and CompletingHash === opt.pattern
        if opts = opt.pattern.candidate(arg, false, argpat)
          opts.map!(&:last)
        end
      end
    end
    list.concat(opts)
  end
  list
end

No documentation available

complete(typ, opt, icase = false, *pat)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1727
def complete(typ, opt, icase = false, *pat)
  if pat.empty?
    search(typ, opt) {|sw| return [sw, opt]} # exact match or...
  end
  raise AmbiguousOption, catch(:ambiguous) {
    visit(:complete, typ, opt, icase, *pat) {|o, *sw| return sw}
    raise InvalidOption, opt
  }
end

Completes shortened long style option switch and returns pair of canonical switch and switch descriptor OptionParser::Switch.

typ: Searching table.
opt: Searching key.
icase: Search case insensitive if true.
pat: Optional pattern for completion.

def_head_option(*opts, &block)

2.3 View on GitHub

An alias for

def_option(*opts, &block)

2.3 View on GitHub

An alias for

def_tail_option(*opts, &block)

2.3 View on GitHub

An alias for

define(*opts, &block)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1462
def define(*opts, &block)
  top.append(*(sw = make_switch(opts, block)))
  sw[0]
end

No documentation available

define_head(*opts, &block)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1477
def define_head(*opts, &block)
  top.prepend(*(sw = make_switch(opts, block)))
  sw[0]
end

No documentation available

define_tail(*opts, &block)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1491
def define_tail(*opts, &block)
  base.append(*(sw = make_switch(opts, block)))
  sw[0]
end

No documentation available

environment(env = File.basename($0, '.*'))

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1795
def environment(env = File.basename($0, '.*'))
  env = ENV[env] || ENV[env.upcase] or return
  require 'shellwords'
  parse(*Shellwords.shellwords(env))
end

Parses environment variable env or its uppercase with splitting like a shell.

env defaults to the basename of the program.

getopts(*args)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1656
def getopts(*args)
  argv = Array === args.first ? args.shift : default_argv
  single_options, *long_options = *args

  result = {}

  single_options.scan(/(.)(:)?/) do |opt, val|
    if val
      result[opt] = nil
      define("-#{opt} VAL")
    else
      result[opt] = false
      define("-#{opt}")
    end
  end if single_options

  long_options.each do |arg|
    arg, desc = arg.split(';', 2)
    opt, val = arg.split(':', 2)
    if val
      result[opt] = val.empty? ? nil : val
      define("--#{opt}=#{result[opt] || "VAL"}", *[desc].compact)
    else
      result[opt] = false
      define("--#{opt}", *[desc].compact)
    end
  end

  parse_in_order(argv, result.method(:[]=))
  result
end

Wrapper method for getopts.rb.

params = ARGV.getopts("ab:", "foo", "bar:", "zot:Z;zot option)
# params[:a] = true   # -a
# params[:b] = "1"    # -b1
# params[:foo] = "1"  # --foo
# params[:bar] = "x"  # --bar x
# params[:zot] = "z"  # --zot Z

help

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1248
def help; summarize("#{banner}".sub(/\n?\z/, "\n")) end

Returns option summary string.

inc(*args)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1043
def inc(*args)
  self.class.inc(*args)
end

No documentation available

load(filename = nil)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1775
def load(filename = nil)
  begin
    filename ||= File.expand_path(File.basename($0, '.*'), '~/.options')
  rescue
    return false
  end
  begin
    parse(*IO.readlines(filename).each {|s| s.chomp!})
    true
  rescue Errno::ENOENT, Errno::ENOTDIR
    false
  end
end

Loads options from file names as filename. Does nothing when the file is not present. Returns whether successfully loaded.

filename defaults to basename of the program without suffix in a directory ~/.options.

make_switch(opts, block = nil)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1332
def make_switch(opts, block = nil)
  short, long, nolong, style, pattern, conv, not_pattern, not_conv, not_style = [], [], []
  ldesc, sdesc, desc, arg = [], [], []
  default_style = Switch::NoArgument
  default_pattern = nil
  klass = nil
  q, a = nil
  has_arg = false

  opts.each do |o|
    # argument class
    next if search(:atype, o) do |pat, c|
      klass = notwice(o, klass, 'type')
      if not_style and not_style != Switch::NoArgument
        not_pattern, not_conv = pat, c
      else
        default_pattern, conv = pat, c
      end
    end

    # directly specified pattern(any object possible to match)
    if (!(String === o || Symbol === o)) and o.respond_to?(:match)
      pattern = notwice(o, pattern, 'pattern')
      if pattern.respond_to?(:convert)
        conv = pattern.method(:convert).to_proc
      else
        conv = SPLAT_PROC
      end
      next
    end

    # anything others
    case o
    when Proc, Method
      block = notwice(o, block, 'block')
    when Array, Hash
      case pattern
      when CompletingHash
      when nil
        pattern = CompletingHash.new
        conv = pattern.method(:convert).to_proc if pattern.respond_to?(:convert)
      else
        raise ArgumentError, "argument pattern given twice"
      end
      o.each {|pat, *v| pattern[pat] = v.fetch(0) {pat}}
    when Module
      raise ArgumentError, "unsupported argument type: #{o}", ParseError.filter_backtrace(caller(4))
    when *ArgumentStyle.keys
      style = notwice(ArgumentStyle[o], style, 'style')
    when /^--no-([^\[\]=\s]*)(.+)?/
      q, a = $1, $2
      o = notwice(a ? Object : TrueClass, klass, 'type')
      not_pattern, not_conv = search(:atype, o) unless not_style
      not_style = (not_style || default_style).guess(arg = a) if a
      default_style = Switch::NoArgument
      default_pattern, conv = search(:atype, FalseClass) unless default_pattern
      ldesc << "--no-#{q}"
      long << 'no-' + (q = q.downcase)
      nolong << q
    when /^--\[no-\]([^\[\]=\s]*)(.+)?/
      q, a = $1, $2
      o = notwice(a ? Object : TrueClass, klass, 'type')
      if a
        default_style = default_style.guess(arg = a)
        default_pattern, conv = search(:atype, o) unless default_pattern
      end
      ldesc << "--[no-]#{q}"
      long << (o = q.downcase)
      not_pattern, not_conv = search(:atype, FalseClass) unless not_style
      not_style = Switch::NoArgument
      nolong << 'no-' + o
    when /^--([^\[\]=\s]*)(.+)?/
      q, a = $1, $2
      if a
        o = notwice(NilClass, klass, 'type')
        default_style = default_style.guess(arg = a)
        default_pattern, conv = search(:atype, o) unless default_pattern
      end
      ldesc << "--#{q}"
      long << (o = q.downcase)
    when /^-(\[\^?\]?(?:[^\\\]]|\\.)*\])(.+)?/
      q, a = $1, $2
      o = notwice(Object, klass, 'type')
      if a
        default_style = default_style.guess(arg = a)
        default_pattern, conv = search(:atype, o) unless default_pattern
      else
        has_arg = true
      end
      sdesc << "-#{q}"
      short << Regexp.new(q)
    when /^-(.)(.+)?/
      q, a = $1, $2
      if a
        o = notwice(NilClass, klass, 'type')
        default_style = default_style.guess(arg = a)
        default_pattern, conv = search(:atype, o) unless default_pattern
      end
      sdesc << "-#{q}"
      short << q
    when /^=/
      style = notwice(default_style.guess(arg = o), style, 'style')
      default_pattern, conv = search(:atype, Object) unless default_pattern
    else
      desc.push(o)
    end
  end

  default_pattern, conv = search(:atype, default_style.pattern) unless default_pattern
  if !(short.empty? and long.empty?)
    if has_arg and default_style == Switch::NoArgument
      default_style = Switch::RequiredArgument
    end
    s = (style || default_style).new(pattern || default_pattern,
                                     conv, sdesc, ldesc, arg, desc, block)
  elsif !block
    if style or pattern
      raise ArgumentError, "no switch given", ParseError.filter_backtrace(caller)
    end
    s = desc
  else
    short << pattern
    s = (style || default_style).new(pattern,
                                     conv, nil, nil, arg, desc, block)
  end
  return s, short, long,
    (not_style.new(not_pattern, not_conv, sdesc, ldesc, nil, desc, block) if not_style),
    nolong
end

Creates an OptionParser::Switch from the parameters. The parsed argument value is passed to the given block, where it can be processed.

See at the beginning of OptionParser for some full examples.

opts can include the following elements:

Argument style:

One of the following:

:NONE, :REQUIRED, :OPTIONAL

Argument pattern:

Acceptable option argument format, must be pre-defined with OptionParser.accept or OptionParser#accept, or Regexp. This can appear once or assigned as String if not present, otherwise causes an ArgumentError. Examples:

Float, Time, Array

Possible argument values:

Hash or Array.

[:text, :binary, :auto]
%w[iso-2022-jp shift_jis euc-jp utf8 binary]
{ "jis" => "iso-2022-jp", "sjis" => "shift_jis" }

Long style switch:

Specifies a long style switch which takes a mandatory, optional or no argument. It’s a string of the following form:

"--switch=MANDATORY" or "--switch MANDATORY"
"--switch[=OPTIONAL]"
"--switch"

Short style switch:

Specifies short style switch which takes a mandatory, optional or no argument. It’s a string of the following form:

"-xMANDATORY"
"-x[OPTIONAL]"
"-x"

There is also a special form which matches character range (not full set of regular expression):

"-[a-z]MANDATORY"
"-[a-z][OPTIONAL]"
"-[a-z]"

Argument style and description:

Instead of specifying mandatory or optional arguments directly in the switch parameter, this separate parameter can be used.

"=MANDATORY"
"=[OPTIONAL]"

Description:

Description string for the option.

"Run verbosely"

Handler:

Handler for the parsed argument value. Either give a block or pass a Proc or Method as an argument.

new() { |self| ... }

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1214
def new
  @stack.push(List.new)
  if block_given?
    yield self
  else
    self
  end
end

Pushes a new List.

notwice(obj, prv, msg)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1264
def notwice(obj, prv, msg)
  unless !prv or prv == obj
    raise(ArgumentError, "argument #{msg} given twice: #{obj}",
          ParseError.filter_backtrace(caller(2)))
  end
  obj
end

Checks if an argument is given twice, in which case an ArgumentError is raised. Called from OptionParser#switch only.

obj: New argument.
prv: Previously specified argument.
msg: Exception message.

on(*opts, &block)

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1471
def on(*opts, &block)
  define(*opts, &block)
  self
end

Add option switch and handler. See make_switch for an explanation of parameters.

on_head(*opts, &block)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1485
def on_head(*opts, &block)
  define_head(*opts, &block)
  self
end

Add option switch like with on, but at head of summary.

on_tail(*opts, &block)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1499
def on_tail(*opts, &block)
  define_tail(*opts, &block)
  self
end

Add option switch like with on, but at tail of summary.

order(*argv, &block)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1518
def order(*argv, &block)
  argv = argv[0].dup if argv.size == 1 and Array === argv[0]
  order!(argv, &block)
end

Parses command line arguments argv in order. When a block is given, each non-option argument is yielded.

Returns the rest of argv left unparsed.

order!(argv = default_argv, &nonopt)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1527
def order!(argv = default_argv, &nonopt)
  parse_in_order(argv, &nonopt)
end

Same as order, but removes switches destructively. Non-option arguments remain in argv.

parse(*argv)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1629
def parse(*argv)
  argv = argv[0].dup if argv.size == 1 and Array === argv[0]
  parse!(argv)
end

Parses command line arguments argv in order when environment variable POSIXLY_CORRECT is set, and in permutation mode otherwise.

parse!(argv = default_argv)

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1638
def parse!(argv = default_argv)
  if ENV.include?('POSIXLY_CORRECT')
    order!(argv)
  else
    permute!(argv)
  end
end

Same as parse, but removes switches destructively. Non-option arguments remain in argv.

permute(*argv)

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1609
def permute(*argv)
  argv = argv[0].dup if argv.size == 1 and Array === argv[0]
  permute!(argv)
end

Parses command line arguments argv in permutation mode and returns list of non-option arguments.

permute!(argv = default_argv)

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1618
def permute!(argv = default_argv)
  nonopts = []
  order!(argv, &nonopts.method(:<<))
  argv[0, 0] = nonopts
  argv
end

Same as permute, but removes switches destructively. Non-option arguments remain in argv.

program_name

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            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1149
def program_name
  @program_name || File.basename($0, '.*')
end

Program name to be emitted in error message and default banner, defaults to $0.

reject(*args, &blk)

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1108
def reject(*args, &blk) top.reject(*args, &blk) end

Directs to reject specified class argument.

t: Argument class specifier, any object including Class.

reject(t)

release

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1174
def release
  @release || (defined?(::Release) && ::Release) || (defined?(::RELEASE) && ::RELEASE)
end

Release code

remove

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1226
def remove
  @stack.pop
end

Removes the last List.

search(id, key) { |k| ... }

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1710
def search(id, key)
  block_given = block_given?
  visit(:search, id, key) do |k|
    return block_given ? yield(k) : k
  end
end

Searches key in @stack for id hash and returns or yields the result.

separator(string)

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1508
def separator(string)
  top.append(string, nil, nil)
end

Add separator in summary.

summarize(to = [], width = @summary_width, max = width - 1, indent = @summary_indent, &blk)

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1239
def summarize(to = [], width = @summary_width, max = width - 1, indent = @summary_indent, &blk)
  blk ||= proc {|l| to << (l.index($/, -1) ? l : l + $/)}
  visit(:summarize, {}, {}, width, max, indent, &blk)
  to
end

Puts option summary into to and returns to. Yields each line if a block is given.

to: Output destination, which must have method <<. Defaults to [].
width: Width of left side, defaults to @summary_width.
max: Maximum length allowed for left side, defaults to width - 1.
indent: Indentation, defaults to @summary_indent.

terminate(arg = nil)

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1076
def terminate(arg = nil)
  self.class.terminate(arg)
end

Terminates option parsing. Optional parameter arg is a string pushed back to be the first non-option argument.

to_a

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1254
def to_a; summarize("#{banner}".split(/^/)) end

Returns option summary list.

to_s

2.3 View on GitHub

An alias for

top

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1200
def top
  @stack[-1]
end

Subject of on / on_head, accept / reject

ver

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1181
def ver
  if v = version
    str = "#{program_name} #{[v].join('.')}"
    str << " (#{v})" if v = release
    str
  end
end

Returns version string from program_name, version and release.

version

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1167
def version
  @version || (defined?(::Version) && ::Version)
end

Version

visit(id, *args, &block)

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1699
def visit(id, *args, &block)
  @stack.reverse_each do |el|
    el.send(id, *args, &block)
  end
  nil
end

Traverses @stack, sending each element method id with args and block.

warn(mesg = $!)

2.3 View on GitHub

          
            # File tmp/rubies/ruby-2.3.8/lib/optparse.rb, line 1189
def warn(mesg = $!)
  super("#{program_name}: #{mesg}")
end

No documentation available

Introduction

Features

Minimal example

Generating Help

Required Arguments

Type Coercion

Using Built-in Conversions

Creating Custom Conversions

Complete example

Shell Completion

Further documentation

accept(*args, &blk)

each_const(path, base = ::Object)

getopts(*args)

inc(arg, default = nil)

new(banner = nil, width = 32, indent = ' ' * 4) { |self| ... }

reject(*args, &blk)

search_const(klass, name) { |klass, cname, const| ... }

show_version(*pkgs)

terminate(arg = nil)

top

with(*args, &block)

abort(mesg = $!)

accept(*args, &blk)

banner

base

candidate(word)

complete(typ, opt, icase = false, *pat)

def_head_option(*opts, &block)

def_option(*opts, &block)

def_tail_option(*opts, &block)

define(*opts, &block)

define_head(*opts, &block)

define_tail(*opts, &block)

environment(env = File.basename($0, '.*'))

getopts(*args)

help

inc(*args)

load(filename = nil)

make_switch(opts, block = nil)

new() { |self| ... }

notwice(obj, prv, msg)

on(*opts, &block)

on_head(*opts, &block)

on_tail(*opts, &block)

order(*argv, &block)

order!(argv = default_argv, &nonopt)

parse(*argv)

parse!(argv = default_argv)

permute(*argv)

permute!(argv = default_argv)

program_name

reject(*args, &blk)

release

remove

search(id, key) { |k| ... }

separator(string)

summarize(to = [], width = @summary_width, max = width - 1, indent = @summary_indent, &blk)

terminate(arg = nil)

to_a

to_s

top

ver

version

visit(id, *args, &block)

warn(mesg = $!)

`Shell` Completion