FileTest implements file test operations similar to those used in File::Stat. It exists as a standalone module, and its methods are also insinuated into the File class. (Note that this is not done by inclusion: the interpreter cheats).
Calculates the set of unambiguous abbreviations for a given set of strings.
require 'abbrev' require 'pp' pp Abbrev.abbrev(['ruby']) #=> {"ruby"=>"ruby", "rub"=>"ruby", "ru"=>"ruby", "r"=>"ruby"} pp Abbrev.abbrev(%w{ ruby rules })
Generates:
{ "ruby" => "ruby",
"rub" => "ruby",
"rules" => "rules",
"rule" => "rules",
"rul" => "rules" }
It also provides an array core extension, Array#abbrev.
pp %w{ summer winter }.abbrev
Generates:
{ "summer" => "summer",
"summe" => "summer",
"summ" => "summer",
"sum" => "summer",
"su" => "summer",
"s" => "summer",
"winter" => "winter",
"winte" => "winter",
"wint" => "winter",
"win" => "winter",
"wi" => "winter",
"w" => "winter" }
The Forwardable module provides delegation of specified methods to a designated object, using the methods def_delegator and def_delegators.
For example, say you have a class RecordCollection which contains an array @records. You could provide the lookup method record_number(), which simply calls [] on the @records array, like this:
require 'forwardable' class RecordCollection attr_accessor :records extend Forwardable def_delegator :@records, :[], :record_number end
We can use the lookup method like so:
r = RecordCollection.new r.records = [4,5,6] r.record_number(0) # => 4
Further, if you wish to provide the methods size, <<, and map, all of which delegate to @records, this is how you can do it:
class RecordCollection # re-open RecordCollection class def_delegators :@records, :size, :<<, :map end r = RecordCollection.new r.records = [1,2,3] r.record_number(0) # => 1 r.size # => 3 r << 4 # => [1, 2, 3, 4] r.map { |x| x * 2 } # => [2, 4, 6, 8]
You can even extend regular objects with Forwardable.
my_hash = Hash.new my_hash.extend Forwardable # prepare object for delegation my_hash.def_delegator "STDOUT", "puts" # add delegation for STDOUT.puts() my_hash.puts "Howdy!"
We want to rely on what has come before obviously, but with delegation we can take just the methods we need and even rename them as appropriate. In many cases this is preferable to inheritance, which gives us the entire old interface, even if much of it isn’t needed.
class Queue extend Forwardable def initialize @q = [ ] # prepare delegate object end # setup preferred interface, enq() and deq()... def_delegator :@q, :push, :enq def_delegator :@q, :shift, :deq # support some general Array methods that fit Queues well def_delegators :@q, :clear, :first, :push, :shift, :size end q = Queue.new q.enq 1, 2, 3, 4, 5 q.push 6 q.shift # => 1 while q.size > 0 puts q.deq end q.enq "Ruby", "Perl", "Python" puts q.first q.clear puts q.first
This should output:
2 3 4 5 6 Ruby nil
Be advised, RDoc will not detect delegated methods.
forwardable.rb provides single-method delegation via the def_delegator and def_delegators methods. For full-class delegation via DelegateClass, see delegate.rb.
SingleForwardable can be used to setup delegation at the object level as well.
printer = String.new printer.extend SingleForwardable # prepare object for delegation printer.def_delegator "STDOUT", "puts" # add delegation for STDOUT.puts() printer.puts "Howdy!"
Also, SingleForwardable can be used to set up delegation for a Class or Module.
class Implementation def self.service puts "serviced!" end end module Facade extend SingleForwardable def_delegator :Implementation, :service end Facade.service #=> serviced!
If you want to use both Forwardable and SingleForwardable, you can use methods def_instance_delegator and def_single_delegator, etc.
a = Node.new a << “B” # => <a>B</a> a.b # => <a>B<b/></a> a.b # => <a>B<b/><b/><a> a.b[“x”] = “y” # => <a>B<b/><b x=“y”/></a> a.b.c # => <a>B<c/><b x=“y”/></a> a.b.c << “D” # => <a>B<c>D</c><b x=“y”/></a>
REXML is an XML toolkit for Ruby, in Ruby.
REXML is a pure Ruby, XML 1.0 conforming, non-validating toolkit with an intuitive API. REXML passes 100% of the non-validating Oasis tests, and provides tree, stream, SAX2, pull, and lightweight APIs. REXML also includes a full XPath 1.0 implementation. Since Ruby 1.8, REXML is included in the standard Ruby distribution.
This API documentation can be downloaded from the REXML home page, or can be accessed online
A tutorial is available in the REXML distribution in docs/tutorial.html, or can be accessed online
This library is an interface to secure random number generators which are suitable for generating session keys in HTTP cookies, etc.
You can use this library in your application by requiring it:
require 'securerandom'
It supports the following secure random number generators:
openssl
/dev/urandom
Win32
Generate random hexadecimal strings:
require 'securerandom' p SecureRandom.hex(10) #=> "52750b30ffbc7de3b362" p SecureRandom.hex(10) #=> "92b15d6c8dc4beb5f559" p SecureRandom.hex(13) #=> "39b290146bea6ce975c37cfc23"
Generate random base64 strings:
p SecureRandom.base64(10) #=> "EcmTPZwWRAozdA==" p SecureRandom.base64(10) #=> "KO1nIU+p9DKxGg==" p SecureRandom.base64(12) #=> "7kJSM/MzBJI+75j8"
Generate random binary strings:
p SecureRandom.random_bytes(10) #=> "\016\t{\370g\310pbr\301" p SecureRandom.random_bytes(10) #=> "\323U\030TO\234\357\020\a\337"
Generate UUIDs:
p SecureRandom.uuid #=> "2d931510-d99f-494a-8c67-87feb05e1594" p SecureRandom.uuid #=> "bad85eb9-0713-4da7-8d36-07a8e4b00eab"
This module manipulates strings according to the word parsing rules of the UNIX Bourne shell.
The shellwords() function was originally a port of shellwords.pl, but modified to conform to the Shell & Utilities volume of the IEEE Std 1003.1-2008, 2016 Edition [1].
You can use Shellwords to parse a string into a Bourne shell friendly Array.
require 'shellwords' argv = Shellwords.split('three blind "mice"') argv #=> ["three", "blind", "mice"]
Once you’ve required Shellwords, you can use the split alias String#shellsplit.
argv = "see how they run".shellsplit argv #=> ["see", "how", "they", "run"]
Be careful you don’t leave a quote unmatched.
argv = "they all ran after the farmer's wife".shellsplit #=> ArgumentError: Unmatched double quote: ...
In this case, you might want to use Shellwords.escape, or its alias String#shellescape.
This method will escape the String for you to safely use with a Bourne shell.
argv = Shellwords.escape("special's.txt") argv #=> "special\\'s.txt" system("cat " + argv)
Shellwords also comes with a core extension for Array, Array#shelljoin.
argv = %w{ls -lta lib} system(argv.shelljoin)
You can use this method to create an escaped string out of an array of tokens separated by a space. In this example we used the literal shortcut for Array.new.
Wakou Aoyama
Akinori MUSHA <knu@iDaemons.org>
Akinori MUSHA <knu@iDaemons.org> (current maintainer)
1: IEEE Std 1003.1-2008, 2016 Edition, the Shell & Utilities volume
The Singleton module implements the Singleton pattern.
To use Singleton, include the module in your class.
class Klass include Singleton # ... end
This ensures that only one instance of Klass can be created.
a,b = Klass.instance, Klass.instance a == b # => true Klass.new # => NoMethodError - new is private ...
The instance is created at upon the first call of Klass.instance().
class OtherKlass include Singleton # ... end ObjectSpace.each_object(OtherKlass){} # => 0 OtherKlass.instance ObjectSpace.each_object(OtherKlass){} # => 1
This behavior is preserved under inheritance and cloning.
This above is achieved by:
Making Klass.new and Klass.allocate private.
Overriding Klass.inherited(sub_klass) and Klass.clone() to ensure that the Singleton properties are kept when inherited and cloned.
Providing the Klass.instance() method that returns the same object each time it is called.
Overriding Klass._load(str) to call Klass.instance().
Overriding Klass#clone and Klass#dup to raise TypeErrors to prevent cloning or duping.
Singleton and Marshal By default Singleton’s _dump(depth) returns the empty string. Marshalling by default will strip state information, e.g. instance variables and taint state, from the instance. Classes using Singleton can provide custom _load(str) and _dump(depth) methods to retain some of the previous state of the instance.
require 'singleton' class Example include Singleton attr_accessor :keep, :strip def _dump(depth) # this strips the @strip information from the instance Marshal.dump(@keep, depth) end def self._load(str) instance.keep = Marshal.load(str) instance end end a = Example.instance a.keep = "keep this" a.strip = "get rid of this" a.taint stored_state = Marshal.dump(a) a.keep = nil a.strip = nil b = Marshal.load(stored_state) p a == b # => true p a.keep # => "keep this" p a.strip # => nil
TSort implements topological sorting using Tarjan’s algorithm for strongly connected components.
TSort is designed to be able to be used with any object which can be interpreted as a directed graph.
TSort requires two methods to interpret an object as a graph, tsort_each_node and tsort_each_child.
tsort_each_node is used to iterate for all nodes over a graph.
tsort_each_child is used to iterate for child nodes of a given node.
The equality of nodes are defined by eql? and hash since TSort uses Hash internally.
The following example demonstrates how to mix the TSort module into an existing class (in this case, Hash). Here, we’re treating each key in the hash as a node in the graph, and so we simply alias the required tsort_each_node method to Hash’s each_key method. For each key in the hash, the associated value is an array of the node’s child nodes. This choice in turn leads to our implementation of the required tsort_each_child method, which fetches the array of child nodes and then iterates over that array using the user-supplied block.
require 'tsort' class Hash include TSort alias tsort_each_node each_key def tsort_each_child(node, &block) fetch(node).each(&block) end end {1=>[2, 3], 2=>[3], 3=>[], 4=>[]}.tsort #=> [3, 2, 1, 4] {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}.strongly_connected_components #=> [[4], [2, 3], [1]]
A very simple ‘make’ like tool can be implemented as follows:
require 'tsort' class Make def initialize @dep = {} @dep.default = [] end def rule(outputs, inputs=[], &block) triple = [outputs, inputs, block] outputs.each {|f| @dep[f] = [triple]} @dep[triple] = inputs end def build(target) each_strongly_connected_component_from(target) {|ns| if ns.length != 1 fs = ns.delete_if {|n| Array === n} raise TSort::Cyclic.new("cyclic dependencies: #{fs.join ', '}") end n = ns.first if Array === n outputs, inputs, block = n inputs_time = inputs.map {|f| File.mtime f}.max begin outputs_time = outputs.map {|f| File.mtime f}.min rescue Errno::ENOENT outputs_time = nil end if outputs_time == nil || inputs_time != nil && outputs_time <= inputs_time sleep 1 if inputs_time != nil && inputs_time.to_i == Time.now.to_i block.call end end } end def tsort_each_child(node, &block) @dep[node].each(&block) end include TSort end def command(arg) print arg, "\n" system arg end m = Make.new m.rule(%w[t1]) { command 'date > t1' } m.rule(%w[t2]) { command 'date > t2' } m.rule(%w[t3]) { command 'date > t3' } m.rule(%w[t4], %w[t1 t3]) { command 'cat t1 t3 > t4' } m.rule(%w[t5], %w[t4 t2]) { command 'cat t4 t2 > t5' } m.build('t5')
‘tsort.rb’ is wrong name because this library uses Tarjan’s algorithm for strongly connected components. Although ‘strongly_connected_components.rb’ is correct but too long.
Tarjan, “Depth First Search and Linear Graph Algorithms”,
SIAM Journal on Computing, Vol. 1, No. 2, pp. 146-160, June 1972.
define UnicodeNormalize module here so that we don’t have to look it up
In-memory session storage class.
Implements session storage as a global in-memory hash. Session data will only persist for as long as the Ruby interpreter instance does.
A StoreContext is used while validating a single certificate and holds the status involved.
The X509 certificate store holds trusted CA certificates used to verify peer certificates.
The easiest way to create a useful certificate store is:
cert_store = OpenSSL::X509::Store.new cert_store.set_default_paths
This will use your system’s built-in certificates.
If your system does not have a default set of certificates you can obtain a set extracted from Mozilla CA certificate store by cURL maintainers here: curl.haxx.se/docs/caextract.html (You may wish to use the firefox-db2pem.sh script to extract the certificates from a local install to avoid man-in-the-middle attacks.)
After downloading or generating a cacert.pem from the above link you can create a certificate store from the pem file like this:
cert_store = OpenSSL::X509::Store.new cert_store.add_file 'cacert.pem'
The certificate store can be used with an SSLSocket like this:
ssl_context = OpenSSL::SSL::SSLContext.new ssl_context.verify_mode = OpenSSL::SSL::VERIFY_PEER ssl_context.cert_store = cert_store tcp_socket = TCPSocket.open 'example.com', 443 ssl_socket = OpenSSL::SSL::SSLSocket.new tcp_socket, ssl_context
File-based session storage class.
Implements session storage as a flat file of ‘key=value’ values. This storage type only works directly with String values; the user is responsible for converting other types to Strings when storing and from Strings when retrieving.
Dummy session storage class.
Implements session storage place holder. No actual storage will be done.
Authenticator for the “DIGEST-MD5” authentication type. See authenticate().
Error raised upon a “NO” response from the server, indicating that the client command could not be completed successfully.
Raised when a bad requirement is encountered
The RequirementList is used to hold the requirements being considered while resolving a set of gems.
The RequirementList acts like a queue where the oldest items are removed first.