class Optimist::Parser
The commandline parser. In typical usage, the methods in this class will be handled internally by Optimist::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 Optimist::with_standard_exception_handling
.
Attributes
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.
The values from the commandline that were not interpreted by parse
.
The complete configuration hashes for each option. (Mainly useful for testing.)
Public Class Methods
Initializes the parser, and instance-evaluates any block given.
# File lib/optimist.rb, line 86 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
The Option
subclasses are responsible for registering themselves using this function.
# File lib/optimist.rb, line 53 def self.register(lookup, klass) @registry[lookup.to_sym] = klass end
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
# File lib/optimist.rb, line 59 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
Public Instance Methods
Marks two (or more!) options as conflicting.
# File lib/optimist.rb, line 195 def conflicts(*syms) syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] } @constraints << [:conflicts, syms] end
Marks two (or more!) options as requiring each other. Only handles undirected (i.e., mutual) dependencies. Directed dependencies are better modeled with Optimist::die
.
# File lib/optimist.rb, line 189 def depends(*syms) syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] } @constraints << [:depends, syms] end
The per-parser version of Optimist::die
(see that for documentation).
# File lib/optimist.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
Print the help message to stream
.
# File lib/optimist.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.description_with_default stream.puts wrap(desc, :width => width - rightcol_start - 1, :prefix => rightcol_start) end end
Instead of displaying “Try –help for help.” on an error display the usage (via educate)
# File lib/optimist.rb, line 230 def educate_on_error @educate_on_error = true end
Marks two (or more!) options as required but mutually exclusive.
# File lib/optimist.rb, line 201 def either(*syms) syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] } @constraints << [:conflicts, syms] @constraints << [:either, syms] end
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 ofSINGLE_ARG_TYPES
, or a corresponding Ruby class (e.g.Integer
for:int
). For multiple-argument parameters, the value can be any member ofMULTI_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 thusOptimist::options
) will have anil
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 totrue
, then if it is specified on the the commandline the value will befalse
. :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, Optimist
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.
# File lib/optimist.rb, line 144 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] @long[o.long] = o.name @short[o.short] = o.name if o.short? @specs[o.name] = o @order << [:opt, o.name] end
Parses the commandline. Typically called by Optimist::options
, but you can call it directly if you need more control.
throws CommandlineError
, HelpNeeded
, and VersionNeeded
exceptions.
# File lib/optimist.rb, line 238 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] } case type when :depends next unless constraint_sym syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym].long} requires --#{@specs[sym].long}" unless given_args.include? sym } when :conflicts next unless constraint_sym syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym].long} conflicts with --#{@specs[sym].long}" if given_args.include?(sym) && (sym != constraint_sym) } when :either raise CommandlineError, "one of #{syms.map { |sym| "--#{@specs[sym].long}" }.join(', ') } is required" if (syms & given_args.keys).size != 1 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 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
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 Optimist
invocation would then be used to parse subcommand options, after shifting the subcommand off of ARGV.
# File lib/optimist.rb, line 216 def stop_on(*words) @stop_words = [*words].flatten end
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.
# File lib/optimist.rb, line 224 def stop_on_unknown @stop_on_unknown = true end
Adds a synopsis (command summary description) right below the usage line, or as the first line if usage isn't specified.
# File lib/optimist.rb, line 175 def synopsis(s = nil) s ? @synopsis = s : @synopsis end
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.
# File lib/optimist.rb, line 169 def usage(s = nil) s ? @usage = s : @usage end
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>”.
# File lib/optimist.rb, line 162 def version(s = nil) s ? @version = s : @version end
Private Instance Methods
instance_eval but with ability to handle block arguments thanks to _why: redhanded.hobix.com/inspect/aBlockCostume.html
# File lib/optimist.rb, line 576 def cloaker(&b) (class << self; self; end).class_eval do define_method :cloaker_, &b meth = instance_method :cloaker_ remove_method :cloaker_ meth end end
# File lib/optimist.rb, line 531 def collect_argument_parameters(args, start_at) params = [] pos = start_at while args[pos] && args[pos] !~ PARAM_RE && !@stop_words.member?(args[pos]) do params << args[pos] pos += 1 end params end
yield successive arg, parameter pairs
# File lib/optimist.rb, line 454 def each_arg(args) remains = [] i = 0 until i >= args.length return remains += args[i..-1] if @stop_words.member? args[i] case args[i] when /^--$/ # arg terminator return remains += args[(i + 1)..-1] when /^--(\S+?)=(.*)$/ # long argument with equals num_params_taken = yield "--#{$1}", [$2] if num_params_taken.nil? remains << args[i] if @stop_on_unknown return remains += args[i + 1..-1] end end i += 1 when /^--(\S+)$/ # long argument params = collect_argument_parameters(args, i + 1) num_params_taken = yield args[i], params if num_params_taken.nil? remains << args[i] if @stop_on_unknown return remains += args[i + 1..-1] end else i += num_params_taken end i += 1 when /^-(\S+)$/ # one or more short arguments short_remaining = "" shortargs = $1.split(//) shortargs.each_with_index do |a, j| if j == (shortargs.length - 1) params = collect_argument_parameters(args, i + 1) num_params_taken = yield "-#{a}", params unless num_params_taken short_remaining << a if @stop_on_unknown remains << "-#{short_remaining}" return remains += args[i + 1..-1] end else i += num_params_taken end else unless yield "-#{a}", [] short_remaining << a if @stop_on_unknown short_remaining += shortargs[j + 1..-1].join remains << "-#{short_remaining}" return remains += args[i + 1..-1] end end end end unless short_remaining.empty? remains << "-#{short_remaining}" end i += 1 else if @stop_on_unknown return remains += args[i..-1] else remains << args[i] i += 1 end end end remains end
# File lib/optimist.rb, line 413 def legacy_width # Support for older Rubies where io/console is not available `tput cols`.to_i rescue Errno::ENOENT 80 end
# File lib/optimist.rb, line 541 def resolve_default_short_options! @order.each do |type, name| opts = @specs[name] next if type != :opt || opts.short c = opts.long.split(//).find { |d| d !~ INVALID_SHORT_ARG_REGEX && !@short.member?(d) } if c # found a character to use opts.short = c @short[c] = name end end end
# File lib/optimist.rb, line 554 def wrap_line(str, opts = {}) prefix = opts[:prefix] || 0 width = opts[:width] || (self.width - 1) start = 0 ret = [] until start > str.length nextt = if start + width >= str.length str.length else x = str.rindex(/\s/, start + width) x = str.index(/\s/, start) if x && x < start x || str.length end ret << ((ret.empty? && !opts[:inner]) ? "" : " " * prefix) + str[start...nextt] start = nextt + 1 end ret end