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/Ruby 3

class OptionParser

Parent:: Object

`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:

$ ruby optparse-test.rb -r
optparse-test.rb:9:in `<main>': missing argument: -r (OptionParser::MissingArgument)
$ 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 below.

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:

$ ruby optparse-test.rb  -t nonsense
... invalid argument: -t nonsense (OptionParser::InvalidArgument)
$ ruby optparse-test.rb  -t 10-11-12
2010-11-12 00:00:00 -0500
$ 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!

Used:

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

Store options to a `Hash`

The into option of order, parse and so on methods stores command line options into a Hash.

require 'optparse'

params = {}
OptionParser.new do |opts|
  opts.on('-a')
  opts.on('-b NUM', Integer)
  opts.on('-v', '--verbose')
end.parse!(into: params)

p params

Used:

$ ruby optparse-test.rb -a
{:a=>true}
$ ruby optparse-test.rb -a -v
{:a=>true, :verbose=>true}
$ ruby optparse-test.rb -a -b 100
{:a=>true, :b=>100}

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.
OctalInteger: Ruby/C like octal/hexadecimal/binary integer format, to be converted to Integer.
Version

Attributes

Heading banner preceding summary.

default_argv[RW]

Strings to be parsed in default.

program_name[W]

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

release[W]

Release code

set_banner[W]

Heading banner preceding summary.

set_program_name[W]

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

set_summary_indent[RW]

Indentation for summary. Must be String (or have + String method).

set_summary_width[RW]

Width for option list portion of summary. Must be Numeric.

summary_indent[RW]

Indentation for summary. Must be String (or have + String method).

summary_width[RW]

Width for option list portion of summary. Must be Numeric.

version[W]

Version

Public Class Methods

accept(*args, &blk) Show source

# File lib/optparse.rb, line 1132
def self.accept(*args, &blk) top.accept(*args, &blk) end

See accept.

each_const(path, base = ::Object) Show source

# File 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

getopts(*args) Show source

# File lib/optparse.rb, line 1742
def self.getopts(*args)
  new.getopts(*args)
end

See getopts.

inc(arg, default = nil) Show source

# File lib/optparse.rb, line 1068
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| ... } Show source

# File lib/optparse.rb, line 1087
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) Show source

# File lib/optparse.rb, line 1145
def self.reject(*args, &blk) top.reject(*args, &blk) end

See reject.

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

# File 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

show_version(*pkgs) Show source

# File 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

terminate(arg = nil) Show source

# File lib/optparse.rb, line 1112
def self.terminate(arg = nil)
  throw :terminate, arg
end

top() Show source

# File lib/optparse.rb, line 1117
def self.top() DefaultList end

with(*args, &block) Show source

# File lib/optparse.rb, line 1059
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.

Public Instance Methods

abort(mesg = $!) Show source

# File lib/optparse.rb, line 1226
def abort(mesg = $!)
  super("#{program_name}: #{mesg}")
end

Calls superclass method Kernel#abort

accept(*args, &blk) Show source

# File lib/optparse.rb, line 1128
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)

additional_message(typ, opt) Show source

# File lib/optparse.rb, line 1793
def additional_message(typ, opt)
  return unless typ and opt and defined?(DidYouMean::SpellChecker)
  all_candidates = []
  visit(:get_candidates, typ) do |candidates|
    all_candidates.concat(candidates)
  end
  all_candidates.select! {|cand| cand.is_a?(String) }
  checker = DidYouMean::SpellChecker.new(dictionary: all_candidates)
  DidYouMean.formatter.message_for(all_candidates & checker.correct(opt))
end

Returns additional info.

# File lib/optparse.rb, line 1170
def banner
  unless @banner
    @banner = +"Usage: #{program_name} [options]"
    visit(:add_banner, @banner)
  end
  @banner
end

Heading banner preceding summary.

base() Show source

# File lib/optparse.rb, line 1240
def base
  @stack[1]
end

Subject of on_tail.

candidate(word) Show source

# File lib/optparse.rb, line 1804
def candidate(word)
  list = []
  case word
  when '-'
    long = short = true
  when /\A--/
    word, arg = word.split(/=/, 2)
    argpat = Completion.regexp(arg, false) if arg and !arg.empty?
    long = true
  when /\A-/
    short = true
  end
  pat = Completion.regexp(word, long)
  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

def_head_option(*opts, &block)

Alias for: define_head

def_option(*opts, &block)

Alias for: define

def_tail_option(*opts, &block)

Alias for: define_tail

define(*opts, &block) Show source

# File lib/optparse.rb, line 1501
def define(*opts, &block)
  top.append(*(sw = make_switch(opts, block)))
  sw[0]
end

Also aliased as: def_option

define_by_keywords(options, meth, **opts) Show source

# File lib/optparse/kwargs.rb, line 5
def define_by_keywords(options, meth, **opts)
  meth.parameters.each do |type, name|
    case type
    when :key, :keyreq
      op, cl = *(type == :key ? %w"[ ]" : ["", ""])
      define("--#{name}=#{op}#{name.upcase}#{cl}", *opts[name]) do |o|
        options[name] = o
      end
    end
  end
  options
end

define_head(*opts, &block) Show source

# File lib/optparse.rb, line 1516
def define_head(*opts, &block)
  top.prepend(*(sw = make_switch(opts, block)))
  sw[0]
end

Also aliased as: def_head_option

define_tail(*opts, &block) Show source

# File lib/optparse.rb, line 1530
def define_tail(*opts, &block)
  base.append(*(sw = make_switch(opts, block)))
  sw[0]
end

Also aliased as: def_tail_option

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

# File lib/optparse.rb, line 1874
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) Show source

# File lib/optparse.rb, line 1707
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() Show source

# File lib/optparse.rb, line 1282
def help; summarize("#{banner}".sub(/\n?\z/, "\n")) end

Returns option summary string.

Also aliased as: to_s

inc(*args) Show source

# File lib/optparse.rb, line 1076
def inc(*args)
  self.class.inc(*args)
end

load(filename = nil) Show source

# File lib/optparse.rb, line 1842
def load(filename = nil)
  unless filename
    basename = File.basename($0, '.*')
    return true if load(File.expand_path(basename, '~/.options')) rescue nil
    basename << ".options"
    return [
      # XDG
      ENV['XDG_CONFIG_HOME'],
      '~/.config',
      *ENV['XDG_CONFIG_DIRS']&.split(File::PATH_SEPARATOR),

      # Haiku
      '~/config/settings',
    ].any? {|dir|
      next if !dir or dir.empty?
      load(File.expand_path(basename, dir)) rescue nil
    }
  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, then the basename with '.options' suffix under XDG and Haiku standard places.

make_switch(opts, block = nil) Show source

# File lib/optparse.rb, line 1368
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}"
      (q = q.downcase).tr!('_', '-')
      long << "no-#{q}"
      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}"
      (o = q.downcase).tr!('_', '-')
      long << o
      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}"
      (o = q.downcase).tr!('_', '-')
      long << o
    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"

If you give multiple description strings, each string will be printed line by line.

Handler:

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

new() { |self| ... } Show source

# File lib/optparse.rb, line 1247
def new
  @stack.push(List.new)
  if block_given?
    yield self
  else
    self
  end
end

Pushes a new List.

on(*opts, &block) Show source

# File lib/optparse.rb, line 1510
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) Show source

# File lib/optparse.rb, line 1524
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) Show source

# File lib/optparse.rb, line 1538
def on_tail(*opts, &block)
  define_tail(*opts, &block)
  self
end

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

order(*argv, into: nil, &nonopt) Show source

# File lib/optparse.rb, line 1560
def order(*argv, into: nil, &nonopt)
  argv = argv[0].dup if argv.size == 1 and Array === argv[0]
  order!(argv, into: into, &nonopt)
end

Parses command line arguments argv in order. When a block is given, each non-option argument is yielded. When optional into keyword argument is provided, the parsed option values are stored there via []= method (so it can be Hash, or OpenStruct, or other similar object).

Returns the rest of argv left unparsed.

order!(argv = default_argv, into: nil, &nonopt) Show source

# File lib/optparse.rb, line 1569
def order!(argv = default_argv, into: nil, &nonopt)
  setter = ->(name, val) {into[name.to_sym] = val} if into
  parse_in_order(argv, setter, &nonopt)
end

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

parse(*argv, into: nil) Show source

# File lib/optparse.rb, line 1680
def parse(*argv, into: nil)
  argv = argv[0].dup if argv.size == 1 and Array === argv[0]
  parse!(argv, into: into)
end

Parses command line arguments argv in order when environment variable POSIXLY_CORRECT is set, and in permutation mode otherwise. When optional into keyword argument is provided, the parsed option values are stored there via []= method (so it can be Hash, or OpenStruct, or other similar object).

parse!(argv = default_argv, into: nil) Show source

# File lib/optparse.rb, line 1689
def parse!(argv = default_argv, into: nil)
  if ENV.include?('POSIXLY_CORRECT')
    order!(argv, into: into)
  else
    permute!(argv, into: into)
  end
end

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

permute(*argv, into: nil) Show source

# File lib/optparse.rb, line 1657
def permute(*argv, into: nil)
  argv = argv[0].dup if argv.size == 1 and Array === argv[0]
  permute!(argv, into: into)
end

Parses command line arguments argv in permutation mode and returns list of non-option arguments. When optional into keyword argument is provided, the parsed option values are stored there via []= method (so it can be Hash, or OpenStruct, or other similar object).

permute!(argv = default_argv, into: nil) Show source

# File lib/optparse.rb, line 1666
def permute!(argv = default_argv, into: nil)
  nonopts = []
  order!(argv, into: into, &nonopts.method(:<<))
  argv[0, 0] = nonopts
  argv
end

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

program_name() Show source

# File lib/optparse.rb, line 1182
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) Show source

# File lib/optparse.rb, line 1141
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() Show source

# File lib/optparse.rb, line 1207
def release
  (defined?(@release) && @release) || (defined?(::Release) && ::Release) || (defined?(::RELEASE) && ::RELEASE)
end

Release code

remove() Show source

# File lib/optparse.rb, line 1259
def remove
  @stack.pop
end

Removes the last List.

separator(string) Show source

# File lib/optparse.rb, line 1547
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) Show source

# File lib/optparse.rb, line 1272
def summarize(to = [], width = @summary_width, max = width - 1, indent = @summary_indent, &blk)
  nl = "\n"
  blk ||= proc {|l| to << (l.index(nl, -1) ? l : l + nl)}
  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) Show source

# File lib/optparse.rb, line 1109
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() Show source

# File lib/optparse.rb, line 1288
def to_a; summarize("#{banner}".split(/^/)) end

Returns option summary list.

to_s()

Alias for: help

top() Show source

# File lib/optparse.rb, line 1233
def top
  @stack[-1]
end

Subject of on / on_head, accept / reject

ver() Show source

# File lib/optparse.rb, line 1214
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() Show source

# File lib/optparse.rb, line 1200
def version
  (defined?(@version) && @version) || (defined?(::Version) && ::Version)
end

Version

warn(mesg = $!) Show source

# File lib/optparse.rb, line 1222
def warn(mesg = $!)
  super("#{program_name}: #{mesg}")
end

Calls superclass method Kernel#warn

Private Instance Methods

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

# File lib/optparse.rb, line 1778
def complete(typ, opt, icase = false, *pat)
  if pat.empty?
    search(typ, opt) {|sw| return [sw, opt]} # exact match or...
  end
  ambiguous = catch(:ambiguous) {
    visit(:complete, typ, opt, icase, *pat) {|o, *sw| return sw}
  }
  exc = ambiguous ? AmbiguousOption : InvalidOption
  raise exc.new(opt, additional: self.method(:additional_message).curry[typ])
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.

notwice(obj, prv, msg) Show source

# File lib/optparse.rb, line 1298
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.

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

# File lib/optparse.rb, line 1761
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.

visit(id, *args, &block) Show source

# File lib/optparse.rb, line 1750
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.

Ruby Core © 1993–2020 Yukihiro Matsumoto
Licensed under the Ruby License.
Ruby Standard Library © contributors
Licensed under their own licenses.

class OptionParser

OptionParser

Introduction

Features

Minimal example

Generating Help

Required Arguments

Type Coercion

Using Built-in Conversions

Creating Custom Conversions

Store options to a Hash

Complete example

Shell Completion

Further documentation

`OptionParser`

Store options to a `Hash`

Shell `Completion`