front end
each switches
options list
errors on parsing
+--------------+
| OptionParser |<>-----+
+--------------+       |                      +--------+
                       |                    ,-| Switch |
     on_head -------->+---------------+    /  +--------+
     accept/reject -->| List          |<|>-
                      |               |<|>-  +----------+
     on ------------->+---------------+    `-| argument |
                        :           :        |  class   |
                      +---------------+      |==========|
     on_tail -------->|               |      |pattern   |
                      +---------------+      |----------|
OptionParser.accept ->| DefaultList   |      |converter |
             reject   |(shared between|      +----------+
                      | all instances)|
                      +---------------+
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.
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.
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
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 CODES = %w[iso-2022-jp shift_jis euc-jp utf8 binary] CODE_ALIASES = { "jis" => "iso-2022-jp", "sjis" => "shift_jis" } # # Return a structure describing the options. # def self.parse(args) # The options specified on the command line will be collected in *options*. # We set default values here. options = OpenStruct.new options.library = [] options.inplace = false options.encoding = "utf8" options.transfer_type = :auto options.verbose = false opts = OptionParser.new do |opts| opts.banner = "Usage: example.rb [options]" opts.separator "" opts.separator "Specific options:" # Mandatory argument. opts.on("-r", "--require LIBRARY", "Require the LIBRARY before executing your script") do |lib| options.library << lib end # Optional argument; multi-line description. opts.on("-i", "--inplace [EXTENSION]", "Edit ARGV files in place", " (make backup if EXTENSION supplied)") do |ext| options.inplace = true options.extension = ext || '' options.extension.sub!(/\A\.?(?=.)/, ".") # Ensure extension begins with dot. end # Cast 'delay' argument to a Float. opts.on("--delay N", Float, "Delay N seconds before executing") do |n| options.delay = n end # Cast 'time' argument to a Time object. opts.on("-t", "--time [TIME]", Time, "Begin execution at given time") do |time| options.time = time end # Cast to octal integer. opts.on("-F", "--irs [OCTAL]", OptionParser::OctalInteger, "Specify record separator (default \\0)") do |rs| options.record_separator = rs end # List of arguments. opts.on("--list x,y,z", Array, "Example 'list' of arguments") do |list| options.list = list end # 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(',') opts.on("--code CODE", CODES, CODE_ALIASES, "Select encoding", " (#{code_list})") do |encoding| options.encoding = encoding end # Optional argument with keyword completion. opts.on("--type [TYPE]", [:text, :binary, :auto], "Select transfer type (text, binary, auto)") do |t| options.transfer_type = t end # Boolean switch. opts.on("-v", "--[no-]verbose", "Run verbosely") do |v| options.verbose = v end opts.separator "" opts.separator "Common options:" # No argument, shows at tail. This will print an options summary. # Try it and see! opts.on_tail("-h", "--help", "Show this message") do puts opts exit end # Another typical switch to print the version. opts.on_tail("--version", "Show version") do puts OptionParser::Version.join('.') exit end end opts.parse!(args) options end # parse() end # class OptparseExample options = OptparseExample.parse(ARGV) pp options
The above examples should be enough to learn how to use this class. If you have any questions, email me (gsinclair@soyabean.com.au) and I will update this document.
Decimal integer format, to be converted to Integer.
Decimal integer/float number format, to be converted to Integer for integer format, Float for float format.
Ruby/C like octal/hexadecimal/binary integer format, to be converted to Integer.
See accept.
 
               # File optparse.rb, line 830
def self.accept(*args, &blk) top.accept(*args, &blk) end
             
             
               # File optparse/version.rb, line 49
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
      c = klass.const_get(c)
    end
  end
end
             
            See getopts.
 
               # File optparse.rb, line 1411
def self.getopts(*args)
  new.getopts(*args)
end
             
            Returns an incremented value of default according to
arg.
 
               # File optparse.rb, line 766
def self.inc(arg, default = nil)
  case arg
  when Integer
    arg.nonzero?
  when nil
    default.to_i + 1
  end
end
             
            Initializes the instance and yields itself if called with a block.
banner
Banner message.
width
Summary width.
indent
Summary indent.
 
               # File optparse.rb, line 785
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
             
            See reject.
 
               # File optparse.rb, line 843
def self.reject(*args, &blk) top.reject(*args, &blk) end
             
             
               # File optparse/version.rb, line 59
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
             
             
               # File optparse/version.rb, line 4
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
             
             
               # File optparse.rb, line 810
def self.terminate(arg = nil)
  throw :terminate, arg
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.
 
               # File optparse.rb, line 757
def self.with(*args, &block)
  opts = new(*args)
  opts.instance_eval(&block)
  opts
end
             
             
               # File optparse.rb, line 924
def abort(mesg = $!)
  super("#{program_name}: #{mesg}")
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)
 
               # File optparse.rb, line 826
def accept(*args, &blk) top.accept(*args, &blk) end
             
            Subject of on_tail.
 
               # File optparse.rb, line 938
def base
  @stack[1]
end
             
             
               # File optparse.rb, line 1187
def define(*opts, &block)
  top.append(*(sw = make_switch(opts, block)))
  sw[0]
end
             
             
               # File optparse.rb, line 1202
def define_head(*opts, &block)
  top.prepend(*(sw = make_switch(opts, block)))
  sw[0]
end
             
             
               # File optparse.rb, line 1216
def define_tail(*opts, &block)
  base.append(*(sw = make_switch(opts, block)))
  sw[0]
end
             
            Parses environment variable env or its uppercase with
splitting like a shell.
env defaults to the basename of the program.
 
               # File optparse.rb, line 1485
def environment(env = File.basename($0, '.*'))
  env = ENV[env] || ENV[env.upcase] or return
  require 'shellwords'
  parse(*Shellwords.shellwords(env))
end
             
            Wrapper method for getopts.rb.
params = ARGV.getopts("ab:", "foo", "bar:") # params[:a] = true # -a # params[:b] = "1" # -b1 # params[:foo] = "1" # --foo # params[:bar] = "x" # --bar x
 
               # File optparse.rb, line 1377
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|
    opt, val = arg.split(':', 2)
    if val
      result[opt] = val.empty? ? nil : val
      define("--#{opt} VAL")
    else
      result[opt] = false
      define("--#{opt}")
    end
  end
  parse_in_order(argv, result.method(:[]=))
  result
end
             
            Returns option summary string.
 
               # File optparse.rb, line 979
def help; summarize(banner.to_s.sub(/\n?\z/, "\n")) end
             
             
               # File optparse.rb, line 774
def inc(*args)
  self.class.inc(*args)
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.
 
               # File optparse.rb, line 1465
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
             
            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:
One of the following:
:NONE, :REQUIRED, :OPTIONAL
Acceptable option argument format, must be pre-defined with #accept or #accept, or Regexp. This can appear once or assigned as String if not present, otherwise causes an ArgumentError. Examples:
Float, Time, Array
Hash or Array.
[:text, :binary, :auto] %w[iso-2022-jp shift_jis euc-jp utf8 binary] { "jis" => "iso-2022-jp", "sjis" => "shift_jis" }
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"
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]"
Instead of specifying mandatory or optional arguments directly in the switch parameter, this separate parameter can be used.
"=MANDATORY" "=[OPTIONAL]"
Description string for the option.
"Run verbosely"
Handler for the parsed argument value. Either give a block or pass a Proc or Method as an argument.
 
               # File optparse.rb, line 1063
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
  n, q, a = nil
  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
      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?)
    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
             
            Pushes a new List.
 
               # File optparse.rb, line 945
def new
  @stack.push(List.new)
  if block_given?
    yield self
  else
    self
  end
end
             
            Add option switch and handler. See make_switch for an explanation of parameters.
 
               # File optparse.rb, line 1196
def on(*opts, &block)
  define(*opts, &block)
  self
end
             
            Add option switch like with on, but at head of summary.
 
               # File optparse.rb, line 1210
def on_head(*opts, &block)
  define_head(*opts, &block)
  self
end
             
            Add option switch like with on, but at tail of summary.
 
               # File optparse.rb, line 1224
def on_tail(*opts, &block)
  define_tail(*opts, &block)
  self
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.
 
               # File optparse.rb, line 1243
def order(*argv, &block)
  argv = argv[0].dup if argv.size == 1 and Array === argv[0]
  order!(argv, &block)
end
             
            Same as order, but removes switches destructively.
 
               # File optparse.rb, line 1251
def order!(argv = default_argv, &nonopt)
  parse_in_order(argv, &nonopt)
end
             
            Parses command line arguments argv in order when environment
variable POSIXLY_CORRECT is set, and in permutation mode otherwise.
 
               # File optparse.rb, line 1352
def parse(*argv)
  argv = argv[0].dup if argv.size == 1 and Array === argv[0]
  parse!(argv)
end
             
            Same as parse, but removes switches destructively.
 
               # File optparse.rb, line 1360
def parse!(argv = default_argv)
  if ENV.include?('POSIXLY_CORRECT')
    order!(argv)
  else
    permute!(argv)
  end
end
             
            Parses command line arguments argv in permutation mode and
returns list of non-option arguments.
 
               # File optparse.rb, line 1333
def permute(*argv)
  argv = argv[0].dup if argv.size == 1 and Array === argv[0]
  permute!(argv)
end
             
            Same as permute, but removes switches destructively.
 
               # File optparse.rb, line 1341
def permute!(argv = default_argv)
  nonopts = []
  order!(argv, &nonopts.method(:<<))
  argv[0, 0] = nonopts
  argv
end
             
            Program name to be emitted in error message and default banner, defaults to $0.
 
               # File optparse.rb, line 880
def program_name
  @program_name || File.basename($0, '.*')
end
             
            Directs to reject specified class argument.
t
Argument class specifier, any object including Class.
reject(t)
 
               # File optparse.rb, line 839
def reject(*args, &blk) top.reject(*args, &blk) end
             
            Release code
 
               # File optparse.rb, line 905
def release
  @release || (defined?(::Release) && ::Release) || (defined?(::RELEASE) && ::RELEASE)
end
             
            Removes the last List.
 
               # File optparse.rb, line 957
def remove
  @stack.pop
end
             
            Add separator in summary.
 
               # File optparse.rb, line 1233
def separator(string)
  top.append(string, nil, nil)
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.
 
               # File optparse.rb, line 970
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
             
            Terminates option parsing. Optional parameter arg is a string
pushed back to be the first non-option argument.
 
               # File optparse.rb, line 807
def terminate(arg = nil)
  self.class.terminate(arg)
end
             
            Returns option summary list.
 
               # File optparse.rb, line 985
def to_a; summarize(banner.to_a.dup) end
             
            Returns version string from #program_name, version and release.
 
               # File optparse.rb, line 912
def ver
  if v = version
    str = "#{program_name} #{[v].join('.')}"
    str << " (#{v})" if v = release
    str
  end
end