Class: Trollop::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/rbcli/util/trollop.rb

Overview

The commandline parser. In typical usage, the methods in this class will be handled internally by Trollop::options. In this case, only the #opt, #banner and #version, #depends, and #conflicts methods will typically be called.

If you want to instantiate this class yourself (for more complicated argument-parsing logic), call #parse to actually produce the output hash, and consider calling it from within Trollop::with_standard_exception_handling.

Constant Summary collapse

INVALID_SHORT_ARG_REGEX =

:nodoc:

/[\d-]/

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*a, &b) ⇒ Parser

Initializes the parser, and instance-evaluates any block given.



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# File 'lib/rbcli/util/trollop.rb', line 90

def initialize(*a, &b)
	@version = nil
	@leftovers = []
	@specs = {}
	@long = {}
	@short = {}
	@order = []
	@constraints = []
	@stop_words = []
	@stop_on_unknown = false
	@educate_on_error = false
	@synopsis = nil
	@usage = nil

	# instance_eval(&b) if b # can't take arguments
	cloaker(&b).bind(self).call(*a) if b
end

Instance Attribute Details

#ignore_invalid_options ⇒ Object

A flag that determines whether or not to raise an error if the parser is passed one or more

options that were not registered ahead of time.  If 'true', then the parser will simply
ignore options that it does not recognize.



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# File 'lib/rbcli/util/trollop.rb', line 87

def ignore_invalid_options
  @ignore_invalid_options
end

#leftovers ⇒ Object (readonly)

The values from the commandline that were not interpreted by #parse.



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# File 'lib/rbcli/util/trollop.rb', line 78

def leftovers
  @leftovers
end

#specs ⇒ Object (readonly)

The complete configuration hashes for each option. (Mainly useful for testing.)



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# File 'lib/rbcli/util/trollop.rb', line 82

def specs
  @specs
end

Class Method Details

.register(lookup, klass) ⇒ Object

The Option subclasses are responsible for registering themselves using this function.



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# File 'lib/rbcli/util/trollop.rb', line 57

def self.register(lookup, klass)
	@registry[lookup.to_sym] = klass
end

.registry_getopttype(type) ⇒ Object

Gets the class from the registry. Can be given either a class-name, e.g. Integer, a string, e.g “integer”, or a symbol, e.g :integer

Raises:

  • (ArgumentError) 


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# File 'lib/rbcli/util/trollop.rb', line 63

def self.registry_getopttype(type)
	return nil unless type
	if type.respond_to?(:name)
		type = type.name
		lookup = type.downcase.to_sym
	else
		lookup = type.to_sym
	end
	raise ArgumentError, "Unsupported argument type '#{type}', registry lookup '#{lookup}'" unless @registry.has_key?(lookup)
	return @registry[lookup].new
end

Instance Method Details

Adds text to the help display. Can be interspersed with calls to #opt to build a multi-section help page.



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# File 'lib/rbcli/util/trollop.rb', line 187

def banner(s)
	@order << [:text, s]
end

#conflicts(*syms) ⇒ Object

Marks two (or more!) options as conflicting.



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# File 'lib/rbcli/util/trollop.rb', line 201

def conflicts(*syms)
	syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] }
	@constraints << [:conflicts, syms]
end

#depends(*syms) ⇒ Object

Marks two (or more!) options as requiring each other. Only handles undirected (i.e., mutual) dependencies. Directed dependencies are better modeled with Trollop::die.



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# File 'lib/rbcli/util/trollop.rb', line 195

def depends(*syms)
	syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] }
	@constraints << [:depends, syms]
end

#die(arg, msg = nil, error_code = nil) ⇒ Object

The per-parser version of Trollop::die (see that for documentation).



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# File 'lib/rbcli/util/trollop.rb', line 435

def die(arg, msg = nil, error_code = nil)
	msg, error_code = nil, msg if msg.kind_of?(Integer)
	if msg
		$stderr.puts "Error: argument --#{@specs[arg].long} #{msg}."
	else
		$stderr.puts "Error: #{arg}."
	end
	if @educate_on_error
		$stderr.puts
		educate $stderr
	else
		$stderr.puts "Try --help for help."
	end
	exit(error_code || -1)
end

#educate(stream = $stdout) ⇒ Object

Print the help message to stream.



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# File 'lib/rbcli/util/trollop.rb', line 366

def educate(stream = $stdout)
	width # hack: calculate it now; otherwise we have to be careful not to
	# call this unless the cursor's at the beginning of a line.

	left = {}
	@specs.each { |name, spec| left[name] = spec.educate }

	leftcol_width = left.values.map(&:length).max || 0
	rightcol_start = leftcol_width + 6 # spaces

	unless @order.size > 0 && @order.first.first == :text
		command_name = File.basename($0).gsub(/\.[^.]+$/, '')
		stream.puts "Usage: #{command_name} #{@usage}\n" if @usage
		stream.puts "#{@synopsis}\n" if @synopsis
		stream.puts if @usage || @synopsis
		stream.puts "#{@version}\n" if @version
		stream.puts "Options:"
	end

	@order.each do |what, opt|
		if what == :text
			stream.puts wrap(opt)
			next
		end

		spec = @specs[opt]
		stream.printf "  %-#{leftcol_width}s    ", left[opt]
		desc = spec.full_description

		stream.puts wrap(desc, :width => width - rightcol_start - 1, :prefix => rightcol_start)
	end
end

#educate_on_error ⇒ Object

Instead of displaying “Try –help for help.” on an error display the usage (via educate)



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# File 'lib/rbcli/util/trollop.rb', line 229

def educate_on_error
	@educate_on_error = true
end

#opt(name, desc = "", opts = {}, &b) ⇒ Object

Define an option. name is the option name, a unique identifier for the option that you will use internally, which should be a symbol or a string. desc is a string description which will be displayed in help messages.

Takes the following optional arguments:

:long

Specify the long form of the argument, i.e. the form with two dashes. If unspecified, will be automatically derived based on the argument name by turning the name option into a string, and replacing any _’s by -‘s.

:short

Specify the short form of the argument, i.e. the form with one dash. If unspecified, will be automatically derived from name. Use :none: to not have a short value.

:type

Require that the argument take a parameter or parameters of type type. For a single parameter, the value can be a member of SINGLE_ARG_TYPES, or a corresponding Ruby class (e.g. Integer for :int). For multiple-argument parameters, the value can be any member of MULTI_ARG_TYPES constant. If unset, the default argument type is :flag, meaning that the argument does not take a parameter. The specification of :type is not necessary if a :default is given.

:default

Set the default value for an argument. Without a default value, the hash returned by #parse (and thus Trollop::options) will have a nil value for this key unless the argument is given on the commandline. The argument type is derived automatically from the class of the default value given, so specifying a :type is not necessary if a :default is given. (But see below for an important caveat when :multi: is specified too.) If the argument is a flag, and the default is set to true, then if it is specified on the the commandline the value will be false.

:required

If set to true, the argument must be provided on the commandline.

:multi

If set to true, allows multiple occurrences of the option on the commandline. Otherwise, only a single instance of the option is allowed. (Note that this is different from taking multiple parameters. See below.)

Note that there are two types of argument multiplicity: an argument can take multiple values, e.g. “–arg 1 2 3”. An argument can also be allowed to occur multiple times, e.g. “–arg 1 –arg 2”.

Arguments that take multiple values should have a :type parameter drawn from MULTI_ARG_TYPES (e.g. :strings), or a :default: value of an array of the correct type (e.g. [String]). The value of this argument will be an array of the parameters on the commandline.

Arguments that can occur multiple times should be marked with :multi => true. The value of this argument will also be an array. In contrast with regular non-multi options, if not specified on the commandline, the default value will be [], not nil.

These two attributes can be combined (e.g. :type => :strings, :multi => true), in which case the value of the argument will be an array of arrays.

There’s one ambiguous case to be aware of: when :multi: is true and a :default is set to an array (of something), it’s ambiguous whether this is a multi-value argument as well as a multi-occurrence argument. In thise case, Trollop assumes that it’s not a multi-value argument. If you want a multi-value, multi-occurrence argument with a default value, you must specify :type as well.

Raises:

  • (ArgumentError) 


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# File 'lib/rbcli/util/trollop.rb', line 148

def opt(name, desc = "", opts = {}, &b)
	opts[:callback] ||= b if block_given?
	opts[:desc] ||= desc

	o = Option.create(name, desc, opts)

	raise ArgumentError, "you already have an argument named '#{name}'" if @specs.member? o.name
	raise ArgumentError, "long option name #{o.long.inspect} is already taken; please specify a (different) :long" if @long[o.long]
	raise ArgumentError, "short option name #{o.short.inspect} is already taken; please specify a (different) :short" if @short[o.short]
	raise ArgumentError, "permitted values for option #{o.long.inspect} must be either nil or an array;" unless o.permitted.nil? or o.permitted.is_a? Array

	@long[o.long] = o.name
	@short[o.short] = o.name if o.short?
	@specs[o.name] = o
	@order << [:opt, o.name]
end

#parse(cmdline = ARGV) ⇒ Object

Parses the commandline. Typically called by Trollop::options, but you can call it directly if you need more control.

throws CommandlineError, HelpNeeded, and VersionNeeded exceptions.

Raises:



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# File 'lib/rbcli/util/trollop.rb', line 237

def parse(cmdline = ARGV)
	vals = {}
	required = {}

	opt :version, "Print version and exit" if @version && ! (@specs[:version] || @long["version"])
	opt :help, "Show this message" unless @specs[:help] || @long["help"]

	@specs.each do |sym, opts|
		required[sym] = true if opts.required?
		vals[sym] = opts.default
		vals[sym] = [] if opts.multi && !opts.default # multi arguments default to [], not nil
	end

	resolve_default_short_options!

	## resolve symbols
	given_args = {}
	@leftovers = each_arg cmdline do |arg, params|
		## handle --no- forms
		arg, negative_given = if arg =~ /^--no-([^-]\S*)$/
														["--#{$1}", true]
													else
														[arg, false]
													end

		sym = case arg
					when /^-([^-])$/      then @short[$1]
					when /^--([^-]\S*)$/  then @long[$1] || @long["no-#{$1}"]
					else                       raise CommandlineError, "invalid argument syntax: '#{arg}'"
					end

		sym = nil if arg =~ /--no-/ # explicitly invalidate --no-no- arguments

		next nil if ignore_invalid_options && !sym
		raise CommandlineError, "unknown argument '#{arg}'" unless sym

		if given_args.include?(sym) && !@specs[sym].multi?
			raise CommandlineError, "option '#{arg}' specified multiple times"
		end

		given_args[sym] ||= {}
		given_args[sym][:arg] = arg
		given_args[sym][:negative_given] = negative_given
		given_args[sym][:params] ||= []

		# The block returns the number of parameters taken.
		num_params_taken = 0

		unless params.empty?
			if @specs[sym].single_arg?
				given_args[sym][:params] << params[0, 1]  # take the first parameter
				num_params_taken = 1
			elsif @specs[sym].multi_arg?
				given_args[sym][:params] << params        # take all the parameters
				num_params_taken = params.size
			end
		end

		num_params_taken
	end

	## check for version and help args
	raise VersionNeeded if given_args.include? :version
	raise HelpNeeded if given_args.include? :help

	## check constraint satisfaction
	@constraints.each do |type, syms|
		constraint_sym = syms.find { |sym| given_args[sym] }
		next unless constraint_sym

		case type
		when :depends
			syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym].long} requires --#{@specs[sym].long}" unless given_args.include? sym }
		when :conflicts
			syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym].long} conflicts with --#{@specs[sym].long}" if given_args.include?(sym) && (sym != constraint_sym) }
		end
	end

	required.each do |sym, val|
		raise CommandlineError, "option --#{@specs[sym].long} must be specified" unless given_args.include? sym
	end

	## parse parameters
	given_args.each do |sym, given_data|
		arg, params, negative_given = given_data.values_at :arg, :params, :negative_given

		opts = @specs[sym]
		if params.empty? && !opts.flag?
			raise CommandlineError, "option '#{arg}' needs a parameter" unless opts.default
			params << (opts.array_default? ? opts.default.clone : [opts.default])
		end

		params[0].each do |p|
			raise CommandlineError, "option '#{arg}' only accepts one of: #{opts.permitted.join(', ')}" unless opts.permitted.include? p
		end unless opts.permitted.nil?

		vals["#{sym}_given".intern] = true # mark argument as specified on the commandline

		vals[sym] = opts.parse(params, negative_given)

		if opts.single_arg?
			if opts.multi?        # multiple options, each with a single parameter
				vals[sym] = vals[sym].map { |p| p[0] }
			else                  # single parameter
				vals[sym] = vals[sym][0][0]
			end
		elsif opts.multi_arg? && !opts.multi?
			vals[sym] = vals[sym][0]  # single option, with multiple parameters
		end
		# else: multiple options, with multiple parameters

		opts.callback.call(vals[sym]) if opts.callback
	end

	## modify input in place with only those
	## arguments we didn't process
	cmdline.clear
	@leftovers.each { |l| cmdline << l }

	## allow openstruct-style accessors
	class << vals
		def method_missing(m, *_args)
			self[m] || self[m.to_s]
		end
	end
	vals
end

#stop_on(*words) ⇒ Object

Defines a set of words which cause parsing to terminate when encountered, such that any options to the left of the word are parsed as usual, and options to the right of the word are left intact.

A typical use case would be for subcommand support, where these would be set to the list of subcommands. A subsequent Trollop invocation would then be used to parse subcommand options, after shifting the subcommand off of ARGV.



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# File 'lib/rbcli/util/trollop.rb', line 215

def stop_on(*words)
	@stop_words = [*words].flatten
end

#stop_on_unknown ⇒ Object

Similar to #stop_on, but stops on any unknown word when encountered (unless it is a parameter for an argument). This is useful for cases where you don’t know the set of subcommands ahead of time, i.e., without first parsing the global options.



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# File 'lib/rbcli/util/trollop.rb', line 223

def stop_on_unknown
	@stop_on_unknown = true
end

#synopsis(s = nil) ⇒ Object

Adds a synopsis (command summary description) right below the usage line, or as the first line if usage isn’t specified.



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# File 'lib/rbcli/util/trollop.rb', line 181

def synopsis(s = nil)
	s ? @synopsis = s : @synopsis
end

#usage(s = nil) ⇒ Object

Sets the usage string. If set the message will be printed as the first line in the help (educate) output and ending in two new lines.



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# File 'lib/rbcli/util/trollop.rb', line 175

def usage(s = nil)
	s ? @usage = s : @usage
end

#version(s = nil) ⇒ Object

Sets the version string. If set, the user can request the version on the commandline. Should probably be of the form “<program name> <version number>”.



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# File 'lib/rbcli/util/trollop.rb', line 168

def version(s = nil)
	s ? @version = s : @version
end

#width ⇒ Object

:nodoc:



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# File 'lib/rbcli/util/trollop.rb', line 399

def width #:nodoc:
	@width ||= if $stdout.tty?
							 begin
								 require 'io/console'
								 w = IO.console.winsize.last
								 w.to_i > 0 ? w : 80
							 rescue LoadError, NoMethodError, Errno::ENOTTY, Errno::EBADF, Errno::EINVAL
								 legacy_width
							 end
						 else
							 80
						 end
end

#wrap(str, opts = {}) ⇒ Object

:nodoc:



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# File 'lib/rbcli/util/trollop.rb', line 421

def wrap(str, opts = {}) # :nodoc:
	if str == ""
		[""]
	else
		inner = false
		str.split("\n").map do |s|
			line = wrap_line s, opts.merge(:inner => inner)
			inner = true
			line
		end.flatten
	end
end