OptionParser
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. See make_switch
for full documentation.
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
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
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:
bash-3.2$ ruby optparse-test.rb -r optparse-test.rb:9:in `<main>': missing argument: -r (OptionParser::MissingArgument) bash-3.2$ ruby optparse-test.rb -r my-library You required my-library!
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 soon.
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:
bash-3.2$ ruby optparse-test.rb -t nonsense ... invalid argument: -t nonsense (OptionParser::InvalidArgument) from ... time.rb:5:in `block in <top (required)>' from optparse-test.rb:31:in `<main>' bash-3.2$ ruby optparse-test.rb -t 10-11-12 2010-11-12 00:00:00 -0500 bash-3.2$ ruby optparse-test.rb -t 9:30 2014-08-13 09:30:00 -0400
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!
output:
bash-3.2$ ruby optparse-test.rb --user 1 #<struct User id=1, name="Sam"> bash-3.2$ ruby optparse-test.rb --user 2 #<struct User id=2, name="Gandalf"> bash-3.2$ ruby optparse-test.rb --user 3 optparse-test.rb:15:in `block in find_user': No User Found for id 3 (RuntimeError)
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.
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.
OptionParser
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. See make_switch
for full documentation.
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
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
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:
bash-3.2$ ruby optparse-test.rb -r optparse-test.rb:9:in `<main>': missing argument: -r (OptionParser::MissingArgument) bash-3.2$ ruby optparse-test.rb -r my-library You required my-library!
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 soon.
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:
bash-3.2$ ruby optparse-test.rb -t nonsense ... invalid argument: -t nonsense (OptionParser::InvalidArgument) from ... time.rb:5:in `block in <top (required)>' from optparse-test.rb:31:in `<main>' bash-3.2$ ruby optparse-test.rb -t 10-11-12 2010-11-12 00:00:00 -0500 bash-3.2$ ruby optparse-test.rb -t 9:30 2014-08-13 09:30:00 -0400
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!
output:
bash-3.2$ ruby optparse-test.rb --user 1 #<struct User id=1, name="Sam"> bash-3.2$ ruby optparse-test.rb --user 2 #<struct User id=2, name="Gandalf"> bash-3.2$ ruby optparse-test.rb --user 3 optparse-test.rb:15:in `block in find_user': No User Found for id 3 (RuntimeError)
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.
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.
Raised when attempting to divide an integer by 0.
42 / 0 #=> ZeroDivisionError: divided by 0
Note that only division by an exact 0 will raise the exception:
42 / 0.0 #=> Float::INFINITY 42 / -0.0 #=> -Float::INFINITY 0 / 0.0 #=> NaN
The Comparable
mixin is used by classes whose objects may be ordered. The class must define the <=>
operator, which compares the receiver against another object, returning -1, 0, or +1 depending on whether the receiver is less than, equal to, or greater than the other object. If the other object is not comparable then the <=>
operator should return nil. Comparable
uses <=>
to implement the conventional comparison operators (<
, <=
, ==
, >=
, and >
) and the method between?
.
class SizeMatters include Comparable attr :str def <=>(other) str.size <=> other.str.size end def initialize(str) @str = str end def inspect @str end end s1 = SizeMatters.new("Z") s2 = SizeMatters.new("YY") s3 = SizeMatters.new("XXX") s4 = SizeMatters.new("WWWW") s5 = SizeMatters.new("VVVVV") s1 < s2 #=> true s4.between?(s1, s3) #=> false s4.between?(s3, s5) #=> true [ s3, s2, s5, s4, s1 ].sort #=> [Z, YY, XXX, WWWW, VVVVV]
Copyright © 2000-2007 Minero Aoki
This program is free software. You can distribute/modify this program under the same terms of ruby.
FileUtils
Namespace for several file utility methods for copying, moving, removing, etc.
Module
Functions require 'fileutils' FileUtils.cd(dir, options) FileUtils.cd(dir, options) {|dir| .... } FileUtils.pwd() FileUtils.mkdir(dir, options) FileUtils.mkdir(list, options) FileUtils.mkdir_p(dir, options) FileUtils.mkdir_p(list, options) FileUtils.rmdir(dir, options) FileUtils.rmdir(list, options) FileUtils.ln(old, new, options) FileUtils.ln(list, destdir, options) FileUtils.ln_s(old, new, options) FileUtils.ln_s(list, destdir, options) FileUtils.ln_sf(src, dest, options) FileUtils.cp(src, dest, options) FileUtils.cp(list, dir, options) FileUtils.cp_r(src, dest, options) FileUtils.cp_r(list, dir, options) FileUtils.mv(src, dest, options) FileUtils.mv(list, dir, options) FileUtils.rm(list, options) FileUtils.rm_r(list, options) FileUtils.rm_rf(list, options) FileUtils.install(src, dest, mode = <src's>, options) FileUtils.chmod(mode, list, options) FileUtils.chmod_R(mode, list, options) FileUtils.chown(user, group, list, options) FileUtils.chown_R(user, group, list, options) FileUtils.touch(list, options)
The options
parameter is a hash of options, taken from the list :force
, :noop
, :preserve
, and :verbose
. :noop
means that no changes are made. The other two are obvious. Each method documents the options that it honours.
All methods that have the concept of a “source” file or directory can take either one file or a list of files in that argument. See the method documentation for examples.
There are some ‘low level’ methods, which do not accept any option:
FileUtils.copy_entry(src, dest, preserve = false, dereference = false) FileUtils.copy_file(src, dest, preserve = false, dereference = true) FileUtils.copy_stream(srcstream, deststream) FileUtils.remove_entry(path, force = false) FileUtils.remove_entry_secure(path, force = false) FileUtils.remove_file(path, force = false) FileUtils.compare_file(path_a, path_b) FileUtils.compare_stream(stream_a, stream_b) FileUtils.uptodate?(file, cmp_list)
FileUtils::Verbose
This module has all methods of FileUtils
module, but it outputs messages before acting. This equates to passing the :verbose
flag to methods in FileUtils
.
FileUtils::NoWrite
This module has all methods of FileUtils
module, but never changes files/directories. This equates to passing the :noop
flag to methods in FileUtils
.
FileUtils::DryRun
This module has all methods of FileUtils
module, but never changes files/directories. This equates to passing the :noop
and :verbose
flags to methods in FileUtils
.
In concurrent programming, a monitor is an object or module intended to be used safely by more than one thread. The defining characteristic of a monitor is that its methods are executed with mutual exclusion. That is, at each point in time, at most one thread may be executing any of its methods. This mutual exclusion greatly simplifies reasoning about the implementation of monitors compared to reasoning about parallel code that updates a data structure.
You can read more about the general principles on the Wikipedia page for Monitors
require 'monitor.rb' buf = [] buf.extend(MonitorMixin) empty_cond = buf.new_cond # consumer Thread.start do loop do buf.synchronize do empty_cond.wait_while { buf.empty? } print buf.shift end end end # producer while line = ARGF.gets buf.synchronize do buf.push(line) empty_cond.signal end end
The consumer thread waits for the producer thread to push a line to buf while buf.empty?
. The producer thread (main thread) reads a line from ARGF and pushes it into buf then calls empty_cond.signal
to notify the consumer thread of new data.
Class
include require 'monitor' class SynchronizedArray < Array include MonitorMixin def initialize(*args) super(*args) end alias :old_shift :shift alias :old_unshift :unshift def shift(n=1) self.synchronize do self.old_shift(n) end end def unshift(item) self.synchronize do self.old_unshift(item) end end # other methods ... end
SynchronizedArray
implements an Array with synchronized access to items. This Class
is implemented as subclass of Array which includes the MonitorMixin
module.
Timeout
long-running blocks
require 'timeout' status = Timeout::timeout(5) { # Something that should be interrupted if it takes more than 5 seconds... }
Timeout
provides a way to auto-terminate a potentially long-running operation if it hasn’t finished in a fixed amount of time.
Previous versions didn’t use a module for namespacing, however timeout
is provided for backwards compatibility. You should prefer Timeout#timeout
instead.
© 2000 Network Applied Communication Laboratory, Inc.
© 2000 Information-technology Promotion Agency, Japan
508 Loop Detected - RFC 5842; experimental 509 Bandwidth Limit Exceeded - Apache bw/limited extension 510 Not Extended - RFC 2774; experimental
Raised when attempting to uninstall a gem that isn’t in GEM_HOME.
Mixin methods for –version and –platform Gem::Command
options.
A C union wrapper
Eigenvalues and eigenvectors of a real matrix.
Computes the eigenvalues and eigenvectors of a matrix A.
If A is diagonalizable, this provides matrices V and D such that A = V*D*V.inv, where D is the diagonal matrix with entries equal to the eigenvalues and V is formed by the eigenvectors.
If A is symmetric, then V is orthogonal and thus A = V*D*V.t
For an m-by-n matrix A with m >= n, the LU decomposition is an m-by-n unit lower triangular matrix L, an n-by-n upper triangular matrix U, and a m-by-m permutation matrix P so that L*U = P*A. If m < n, then L is m-by-m and U is m-by-n.
The LUP decomposition with pivoting always exists, even if the matrix is singular, so the constructor will never fail. The primary use of the LU decomposition is in the solution of square systems of simultaneous linear equations. This will fail if singular? returns true.
This is an abstract class. You never use this directly; it serves as a parent class for the specific declarations.
Raised to indicate that a system exit should occur with the specified exit_code