class 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#
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 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 opt_parser = 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 ::Version.join('.') exit end end opt_parser.parse!(args) options end # parse() end # class OptparseExample options = OptparseExample.parse(ARGV) pp 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
Attributes
Strings to be parsed in default.
Program name to be emitted in error message and default banner, defaults to $0.
Release code
Program name to be emitted in error message and default banner, defaults to $0.
Indentation for summary. Must be String (or have + String method).
Width for option list portion of summary. Must be Numeric.
Indentation for summary. Must be String (or have + String method).
Width for option list portion of summary. Must be Numeric.
Version
Public Class Methods
See accept.
# File lib/optparse.rb, line 954 def self.accept(*args, &blk) top.accept(*args, &blk) end
# File lib/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 klass.const_get(c) end end end
See getopts.
# File lib/optparse.rb, line 1546 def self.getopts(*args) new.getopts(*args) end
Returns an incremented value of default
according to
arg
.
# File lib/optparse.rb, line 890 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 lib/optparse.rb, line 909 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 lib/optparse.rb, line 967 def self.reject(*args, &blk) top.reject(*args, &blk) end
# File lib/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 lib/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 lib/optparse.rb, line 934 def self.terminate(arg = nil) throw :terminate, arg end
# File lib/optparse.rb, line 939 def self.top() DefaultList 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 lib/optparse.rb, line 881 def self.with(*args, &block) opts = new(*args) opts.instance_eval(&block) opts end
Public Instance Methods
# File lib/optparse.rb, line 1048 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 lib/optparse.rb, line 950 def accept(*args, &blk) top.accept(*args, &blk) end
Subject of on_tail.
# File lib/optparse.rb, line 1062 def base @stack[1] end
# File lib/optparse.rb, line 1593 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
# File lib/optparse.rb, line 1317 def define(*opts, &block) top.append(*(sw = make_switch(opts, block))) sw[0] end
# File lib/optparse.rb, line 1332 def define_head(*opts, &block) top.prepend(*(sw = make_switch(opts, block))) sw[0] end
# File lib/optparse.rb, line 1346 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 lib/optparse.rb, line 1650 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:", "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
# File lib/optparse.rb, line 1511 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
Returns option summary string.
# File lib/optparse.rb, line 1103 def help; summarize("#{banner}".sub(/\n?\z/, "\n")) end
# File lib/optparse.rb, line 898 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 lib/optparse.rb, line 1630 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:
- Argument style:
-
One of the following:
:NONE, :REQUIRED, :OPTIONAL
- Argument pattern:
-
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
- 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.
# File lib/optparse.rb, line 1187 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
Pushes a new List.
# File lib/optparse.rb, line 1069 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 lib/optparse.rb, line 1326 def on(*opts, &block) define(*opts, &block) self end
Add option switch like with on, but at head of summary.
# File lib/optparse.rb, line 1340 def on_head(*opts, &block) define_head(*opts, &block) self end
Add option switch like with on, but at tail of summary.
# File lib/optparse.rb, line 1354 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 lib/optparse.rb, line 1373 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. Non-option arguments remain in argv
.
# File lib/optparse.rb, line 1382 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 lib/optparse.rb, line 1484 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. Non-option arguments remain in argv
.
# File lib/optparse.rb, line 1493 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 lib/optparse.rb, line 1464 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. Non-option arguments remain in
argv
.
# File lib/optparse.rb, line 1473 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 lib/optparse.rb, line 1004 def program_name @program_name || File.basename($0, '.*') end
Directs to reject specified class argument.
t
-
Argument class specifier, any object including Class.
reject(t)
# File lib/optparse.rb, line 963 def reject(*args, &blk) top.reject(*args, &blk) end
Release code
# File lib/optparse.rb, line 1029 def release @release || (defined?(::Release) && ::Release) || (defined?(::RELEASE) && ::RELEASE) end
Removes the last List.
# File lib/optparse.rb, line 1081 def remove @stack.pop end
Add separator in summary.
# File lib/optparse.rb, line 1363 def separator(string) top.append(string, nil, nil) end
Puts option summary into to
and returns to
.
Yields each line if a block is given.
to
-
Output destination, which must have method <<. Defaults to [].
width
-
Width of left side, defaults to @summary_width.
max
-
Maximum length allowed for left side, defaults to
width
- 1. indent
-
Indentation, defaults to @summary_indent.
# File lib/optparse.rb, line 1094 def summarize(to = [], width = @summary_width, max = width - 1, indent = @summary_indent, &blk) blk ||= proc {|l| to << (l.index($/, -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 lib/optparse.rb, line 931 def terminate(arg = nil) self.class.terminate(arg) end
Returns option summary list.
# File lib/optparse.rb, line 1109 def to_a; summarize("#{banner}".split(/^/)) end
Returns version string from #program_name, version and release.
# File lib/optparse.rb, line 1036 def ver if v = version str = "#{program_name} #{[v].join('.')}" str << " (#{v})" if v = release str end end
Version
# File lib/optparse.rb, line 1022 def version @version || (defined?(::Version) && ::Version) end
# File lib/optparse.rb, line 1044 def warn(mesg = $!) super("#{program_name}: #{mesg}") end
Private Instance Methods
Completes shortened long style option switch and returns pair of canonical switch and switch descriptor OptionParser::Switch.
id
-
Searching table.
opt
-
Searching key.
icase
-
Search case insensitive if true.
pat
-
Optional pattern for completion.
# File lib/optparse.rb, line 1582 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
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.
# File lib/optparse.rb, line 1119 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
Searches key
in @stack for id
hash and returns or
yields the result.
# File lib/optparse.rb, line 1565 def search(id, key) block_given = block_given? visit(:search, id, key) do |k| return block_given ? yield(k) : k end end
Traverses @stack, sending each element method id
with
args
and block
.
# File lib/optparse.rb, line 1554 def visit(id, *args, &block) @stack.reverse_each do |el| el.send(id, *args, &block) end nil end