Results for: "OptionParser"

Coverage provides coverage measurement feature for Ruby. This feature is experimental, so these APIs may be changed in future.

Caveat: Currently, only process-global coverage measurement is supported. You cannot measure per-thread covearge.

Usage

  1. require “coverage”

  2. do Coverage.start

  3. require or load Ruby source file

  4. Coverage.result will return a hash that contains filename as key and coverage array as value. A coverage array gives, for each line, the number of line execution by the interpreter. A nil value means coverage is disabled for this line (lines like else and end).

Examples

[foo.rb]
s = 0
10.times do |x|
  s += x
end

if s == 45
  p :ok
else
  p :ng
end
[EOF]

require "coverage"
Coverage.start
require "foo.rb"
p Coverage.result  #=> {"foo.rb"=>[1, 1, 10, nil, nil, 1, 1, nil, 0, nil]}

Lines Coverage

If a coverage mode is not explicitly specified when starting coverage, lines coverage is what will run. It reports the number of line executions for each line.

require "coverage"
Coverage.start(lines: true)
require "foo.rb"
p Coverage.result #=> {"foo.rb"=>{:lines=>[1, 1, 10, nil, nil, 1, 1, nil, 0, nil]}}

The value of the lines coverage result is an array containing how many times each line was executed. Order in this array is important. For example, the first item in this array, at index 0, reports how many times line 1 of this file was executed while coverage was run (which, in this example, is one time).

A nil value means coverage is disabled for this line (lines like else and end).

Oneshot Lines Coverage

Oneshot lines coverage tracks and reports on the executed lines while coverage is running. It will not report how many times a line was executed, only that it was executed.

require "coverage"
Coverage.start(oneshot_lines: true)
require "foo.rb"
p Coverage.result #=> {"foo.rb"=>{:oneshot_lines=>[1, 2, 3, 6, 7]}}

The value of the oneshot lines coverage result is an array containing the line numbers that were executed.

Branches Coverage

Branches coverage reports how many times each branch within each conditional was executed.

require "coverage"
Coverage.start(branches: true)
require "foo.rb"
p Coverage.result #=> {"foo.rb"=>{:branches=>{[:if, 0, 6, 0, 10, 3]=>{[:then, 1, 7, 2, 7, 7]=>1, [:else, 2, 9, 2, 9, 7]=>0}}}}

Each entry within the branches hash is a conditional, the value of which is another hash where each entry is a branch in that conditional. The values are the number of times the method was executed, and the keys are identifying information about the branch.

The information that makes up each key identifying branches or conditionals is the following, from left to right:

  1. A label for the type of branch or conditional.

  2. A unique identifier.

  3. The starting line number it appears on in the file.

  4. The starting column number it appears on in the file.

  5. The ending line number it appears on in the file.

  6. The ending column number it appears on in the file.

Methods Coverage

Methods coverage reports how many times each method was executed.

[foo_method.rb]
class Greeter
  def greet
    "welcome!"
  end
end

def hello
  "Hi"
end

hello()
Greeter.new.greet()
[EOF]

require "coverage"
Coverage.start(methods: true)
require "foo_method.rb"
p Coverage.result #=> {"foo_method.rb"=>{:methods=>{[Object, :hello, 7, 0, 9, 3]=>1, [Greeter, :greet, 2, 2, 4, 5]=>1}}}

Each entry within the methods hash represents a method. The values in this hash are the number of times the method was executed, and the keys are identifying information about the method.

The information that makes up each key identifying a method is the following, from left to right:

  1. The class.

  2. The method name.

  3. The starting line number the method appears on in the file.

  4. The starting column number the method appears on in the file.

  5. The ending line number the method appears on in the file.

  6. The ending column number the method appears on in the file.

All Coverage Modes

You can also run all modes of coverage simultaneously with this shortcut. Note that running all coverage modes does not run both lines and oneshot lines. Those modes cannot be run simultaneously. Lines coverage is run in this case, because you can still use it to determine whether or not a line was executed.

require "coverage"
Coverage.start(:all)
require "foo.rb"
p Coverage.result #=> {"foo.rb"=>{:lines=>[1, 1, 10, nil, nil, 1, 1, nil, 0, nil], :branches=>{[:if, 0, 6, 0, 10, 3]=>{[:then, 1, 7, 2, 7, 7]=>1, [:else, 2, 9, 2, 9, 7]=>0}}, :methods=>{}}}

JavaScript Object Notation (JSON)

JSON is a lightweight data-interchange format.

A JSON value is one of the following:

A JSON array or object may contain nested arrays, objects, and scalars to any depth:

{"foo": {"bar": 1, "baz": 2}, "bat": [0, 1, 2]}
[{"foo": 0, "bar": 1}, ["baz", 2]]

Using Module JSON

To make module JSON available in your code, begin with:

require 'json'

All examples here assume that this has been done.

Parsing JSON

You can parse a String containing JSON data using either of two methods:

where

The difference between the two methods is that JSON.parse! omits some checks and may not be safe for some source data; use it only for data from trusted sources. Use the safer method JSON.parse for less trusted sources.

Parsing JSON Arrays

When source is a JSON array, JSON.parse by default returns a Ruby Array:

json = '["foo", 1, 1.0, 2.0e2, true, false, null]'
ruby = JSON.parse(json)
ruby # => ["foo", 1, 1.0, 200.0, true, false, nil]
ruby.class # => Array

The JSON array may contain nested arrays, objects, and scalars to any depth:

json = '[{"foo": 0, "bar": 1}, ["baz", 2]]'
JSON.parse(json) # => [{"foo"=>0, "bar"=>1}, ["baz", 2]]

Parsing JSON Objects

When the source is a JSON object, JSON.parse by default returns a Ruby Hash:

json = '{"a": "foo", "b": 1, "c": 1.0, "d": 2.0e2, "e": true, "f": false, "g": null}'
ruby = JSON.parse(json)
ruby # => {"a"=>"foo", "b"=>1, "c"=>1.0, "d"=>200.0, "e"=>true, "f"=>false, "g"=>nil}
ruby.class # => Hash

The JSON object may contain nested arrays, objects, and scalars to any depth:

json = '{"foo": {"bar": 1, "baz": 2}, "bat": [0, 1, 2]}'
JSON.parse(json) # => {"foo"=>{"bar"=>1, "baz"=>2}, "bat"=>[0, 1, 2]}

Parsing JSON Scalars

When the source is a JSON scalar (not an array or object), JSON.parse returns a Ruby scalar.

String:

ruby = JSON.parse('"foo"')
ruby # => 'foo'
ruby.class # => String

Integer:

ruby = JSON.parse('1')
ruby # => 1
ruby.class # => Integer

Float:

ruby = JSON.parse('1.0')
ruby # => 1.0
ruby.class # => Float
ruby = JSON.parse('2.0e2')
ruby # => 200
ruby.class # => Float

Boolean:

ruby = JSON.parse('true')
ruby # => true
ruby.class # => TrueClass
ruby = JSON.parse('false')
ruby # => false
ruby.class # => FalseClass

Null:

ruby = JSON.parse('null')
ruby # => nil
ruby.class # => NilClass

Parsing Options

Input Options

Option max_nesting (Integer) specifies the maximum nesting depth allowed; defaults to 100; specify false to disable depth checking.

With the default, false:

source = '[0, [1, [2, [3]]]]'
ruby = JSON.parse(source)
ruby # => [0, [1, [2, [3]]]]

Too deep:

# Raises JSON::NestingError (nesting of 2 is too deep):
JSON.parse(source, {max_nesting: 1})

Bad value:

# Raises TypeError (wrong argument type Symbol (expected Fixnum)):
JSON.parse(source, {max_nesting: :foo})

Option allow_nan (boolean) specifies whether to allow NaN, Infinity, and MinusInfinity in source; defaults to false.

With the default, false:

# Raises JSON::ParserError (225: unexpected token at '[NaN]'):
JSON.parse('[NaN]')
# Raises JSON::ParserError (232: unexpected token at '[Infinity]'):
JSON.parse('[Infinity]')
# Raises JSON::ParserError (248: unexpected token at '[-Infinity]'):
JSON.parse('[-Infinity]')

Allow:

source = '[NaN, Infinity, -Infinity]'
ruby = JSON.parse(source, {allow_nan: true})
ruby # => [NaN, Infinity, -Infinity]
Output Options

Option symbolize_names (boolean) specifies whether returned Hash keys should be Symbols; defaults to false (use Strings).

With the default, false:

source = '{"a": "foo", "b": 1.0, "c": true, "d": false, "e": null}'
ruby = JSON.parse(source)
ruby # => {"a"=>"foo", "b"=>1.0, "c"=>true, "d"=>false, "e"=>nil}

Use Symbols:

ruby = JSON.parse(source, {symbolize_names: true})
ruby # => {:a=>"foo", :b=>1.0, :c=>true, :d=>false, :e=>nil}

Option object_class (Class) specifies the Ruby class to be used for each JSON object; defaults to Hash.

With the default, Hash:

source = '{"a": "foo", "b": 1.0, "c": true, "d": false, "e": null}'
ruby = JSON.parse(source)
ruby.class # => Hash

Use class OpenStruct:

ruby = JSON.parse(source, {object_class: OpenStruct})
ruby # => #<OpenStruct a="foo", b=1.0, c=true, d=false, e=nil>

Option array_class (Class) specifies the Ruby class to be used for each JSON array; defaults to Array.

With the default, Array:

source = '["foo", 1.0, true, false, null]'
ruby = JSON.parse(source)
ruby.class # => Array

Use class Set:

ruby = JSON.parse(source, {array_class: Set})
ruby # => #<Set: {"foo", 1.0, true, false, nil}>

Option create_additions (boolean) specifies whether to use JSON additions in parsing. See JSON Additions.

Generating JSON

To generate a Ruby String containing JSON data, use method JSON.generate(source, opts), where

Generating JSON from Arrays

When the source is a Ruby Array, JSON.generate returns a String containing a JSON array:

ruby = [0, 's', :foo]
json = JSON.generate(ruby)
json # => '[0,"s","foo"]'

The Ruby Array array may contain nested arrays, hashes, and scalars to any depth:

ruby = [0, [1, 2], {foo: 3, bar: 4}]
json = JSON.generate(ruby)
json # => '[0,[1,2],{"foo":3,"bar":4}]'

Generating JSON from Hashes

When the source is a Ruby Hash, JSON.generate returns a String containing a JSON object:

ruby = {foo: 0, bar: 's', baz: :bat}
json = JSON.generate(ruby)
json # => '{"foo":0,"bar":"s","baz":"bat"}'

The Ruby Hash array may contain nested arrays, hashes, and scalars to any depth:

ruby = {foo: [0, 1], bar: {baz: 2, bat: 3}, bam: :bad}
json = JSON.generate(ruby)
json # => '{"foo":[0,1],"bar":{"baz":2,"bat":3},"bam":"bad"}'

Generating JSON from Other Objects

When the source is neither an Array nor a Hash, the generated JSON data depends on the class of the source.

When the source is a Ruby Integer or Float, JSON.generate returns a String containing a JSON number:

JSON.generate(42) # => '42'
JSON.generate(0.42) # => '0.42'

When the source is a Ruby String, JSON.generate returns a String containing a JSON string (with double-quotes):

JSON.generate('A string') # => '"A string"'

When the source is true, false or nil, JSON.generate returns a String containing the corresponding JSON token:

JSON.generate(true) # => 'true'
JSON.generate(false) # => 'false'
JSON.generate(nil) # => 'null'

When the source is none of the above, JSON.generate returns a String containing a JSON string representation of the source:

JSON.generate(:foo) # => '"foo"'
JSON.generate(Complex(0, 0)) # => '"0+0i"'
JSON.generate(Dir.new('.')) # => '"#<Dir>"'

Generating Options

Input Options

Option allow_nan (boolean) specifies whether NaN, Infinity, and -Infinity may be generated; defaults to false.

With the default, false:

# Raises JSON::GeneratorError (920: NaN not allowed in JSON):
JSON.generate(JSON::NaN)
# Raises JSON::GeneratorError (917: Infinity not allowed in JSON):
JSON.generate(JSON::Infinity)
# Raises JSON::GeneratorError (917: -Infinity not allowed in JSON):
JSON.generate(JSON::MinusInfinity)

Allow:

ruby = [Float::NaN, Float::Infinity, Float::MinusInfinity]
JSON.generate(ruby, allow_nan: true) # => '[NaN,Infinity,-Infinity]'

Option max_nesting (Integer) specifies the maximum nesting depth in obj; defaults to 100.

With the default, 100:

obj = [[[[[[0]]]]]]
JSON.generate(obj) # => '[[[[[[0]]]]]]'

Too deep:

# Raises JSON::NestingError (nesting of 2 is too deep):
JSON.generate(obj, max_nesting: 2)
Output Options

The default formatting options generate the most compact JSON data, all on one line and with no whitespace.

You can use these formatting options to generate JSON data in a more open format, using whitespace. See also JSON.pretty_generate.

In this example, obj is used first to generate the shortest JSON data (no whitespace), then again with all formatting options specified:

obj = {foo: [:bar, :baz], bat: {bam: 0, bad: 1}}
json = JSON.generate(obj)
puts 'Compact:', json
opts = {
  array_nl: "\n",
  object_nl: "\n",
  indent: '  ',
  space_before: ' ',
  space: ' '
}
puts 'Open:', JSON.generate(obj, opts)

Output:

Compact:
{"foo":["bar","baz"],"bat":{"bam":0,"bad":1}}
Open:
{
  "foo" : [
    "bar",
    "baz"
],
  "bat" : {
    "bam" : 0,
    "bad" : 1
  }
}

JSON Additions

When you “round trip” a non-String object from Ruby to JSON and back, you have a new String, instead of the object you began with:

ruby0 = Range.new(0, 2)
json = JSON.generate(ruby0)
json # => '0..2"'
ruby1 = JSON.parse(json)
ruby1 # => '0..2'
ruby1.class # => String

You can use JSON additions to preserve the original object. The addition is an extension of a ruby class, so that:

This example shows a Range being generated into JSON and parsed back into Ruby, both without and with the addition for Range:

ruby = Range.new(0, 2)
# This passage does not use the addition for Range.
json0 = JSON.generate(ruby)
ruby0 = JSON.parse(json0)
# This passage uses the addition for Range.
require 'json/add/range'
json1 = JSON.generate(ruby)
ruby1 = JSON.parse(json1, create_additions: true)
# Make a nice display.
display = <<EOT
Generated JSON:
  Without addition:  #{json0} (#{json0.class})
  With addition:     #{json1} (#{json1.class})
Parsed JSON:
  Without addition:  #{ruby0.inspect} (#{ruby0.class})
  With addition:     #{ruby1.inspect} (#{ruby1.class})
EOT
puts display

This output shows the different results:

Generated JSON:
  Without addition:  "0..2" (String)
  With addition:     {"json_class":"Range","a":[0,2,false]} (String)
Parsed JSON:
  Without addition:  "0..2" (String)
  With addition:     0..2 (Range)

The JSON module includes additions for certain classes. You can also craft custom additions. See Custom JSON Additions.

Built-in Additions

The JSON module includes additions for certain classes. To use an addition, require its source:

To reduce punctuation clutter, the examples below show the generated JSON via puts, rather than the usual inspect,

BigDecimal:

require 'json/add/bigdecimal'
ruby0 = BigDecimal(0) # 0.0
json = JSON.generate(ruby0) # {"json_class":"BigDecimal","b":"27:0.0"}
ruby1 = JSON.parse(json, create_additions: true) # 0.0
ruby1.class # => BigDecimal

Complex:

require 'json/add/complex'
ruby0 = Complex(1+0i) # 1+0i
json = JSON.generate(ruby0) # {"json_class":"Complex","r":1,"i":0}
ruby1 = JSON.parse(json, create_additions: true) # 1+0i
ruby1.class # Complex

Date:

require 'json/add/date'
ruby0 = Date.today # 2020-05-02
json = JSON.generate(ruby0) # {"json_class":"Date","y":2020,"m":5,"d":2,"sg":2299161.0}
ruby1 = JSON.parse(json, create_additions: true) # 2020-05-02
ruby1.class # Date

DateTime:

require 'json/add/date_time'
ruby0 = DateTime.now # 2020-05-02T10:38:13-05:00
json = JSON.generate(ruby0) # {"json_class":"DateTime","y":2020,"m":5,"d":2,"H":10,"M":38,"S":13,"of":"-5/24","sg":2299161.0}
ruby1 = JSON.parse(json, create_additions: true) # 2020-05-02T10:38:13-05:00
ruby1.class # DateTime

Exception (and its subclasses including RuntimeError):

require 'json/add/exception'
ruby0 = Exception.new('A message') # A message
json = JSON.generate(ruby0) # {"json_class":"Exception","m":"A message","b":null}
ruby1 = JSON.parse(json, create_additions: true) # A message
ruby1.class # Exception
ruby0 = RuntimeError.new('Another message') # Another message
json = JSON.generate(ruby0) # {"json_class":"RuntimeError","m":"Another message","b":null}
ruby1 = JSON.parse(json, create_additions: true) # Another message
ruby1.class # RuntimeError

OpenStruct:

require 'json/add/ostruct'
ruby0 = OpenStruct.new(name: 'Matz', language: 'Ruby') # #<OpenStruct name="Matz", language="Ruby">
json = JSON.generate(ruby0) # {"json_class":"OpenStruct","t":{"name":"Matz","language":"Ruby"}}
ruby1 = JSON.parse(json, create_additions: true) # #<OpenStruct name="Matz", language="Ruby">
ruby1.class # OpenStruct

Range:

require 'json/add/range'
ruby0 = Range.new(0, 2) # 0..2
json = JSON.generate(ruby0) # {"json_class":"Range","a":[0,2,false]}
ruby1 = JSON.parse(json, create_additions: true) # 0..2
ruby1.class # Range

Rational:

require 'json/add/rational'
ruby0 = Rational(1, 3) # 1/3
json = JSON.generate(ruby0) # {"json_class":"Rational","n":1,"d":3}
ruby1 = JSON.parse(json, create_additions: true) # 1/3
ruby1.class # Rational

Regexp:

require 'json/add/regexp'
ruby0 = Regexp.new('foo') # (?-mix:foo)
json = JSON.generate(ruby0) # {"json_class":"Regexp","o":0,"s":"foo"}
ruby1 = JSON.parse(json, create_additions: true) # (?-mix:foo)
ruby1.class # Regexp

Set:

require 'json/add/set'
ruby0 = Set.new([0, 1, 2]) # #<Set: {0, 1, 2}>
json = JSON.generate(ruby0) # {"json_class":"Set","a":[0,1,2]}
ruby1 = JSON.parse(json, create_additions: true) # #<Set: {0, 1, 2}>
ruby1.class # Set

Struct:

require 'json/add/struct'
Customer = Struct.new(:name, :address) # Customer
ruby0 = Customer.new("Dave", "123 Main") # #<struct Customer name="Dave", address="123 Main">
json = JSON.generate(ruby0) # {"json_class":"Customer","v":["Dave","123 Main"]}
ruby1 = JSON.parse(json, create_additions: true) # #<struct Customer name="Dave", address="123 Main">
ruby1.class # Customer

Symbol:

require 'json/add/symbol'
ruby0 = :foo # foo
json = JSON.generate(ruby0) # {"json_class":"Symbol","s":"foo"}
ruby1 = JSON.parse(json, create_additions: true) # foo
ruby1.class # Symbol

Time:

require 'json/add/time'
ruby0 = Time.now # 2020-05-02 11:28:26 -0500
json = JSON.generate(ruby0) # {"json_class":"Time","s":1588436906,"n":840560000}
ruby1 = JSON.parse(json, create_additions: true) # 2020-05-02 11:28:26 -0500
ruby1.class # Time

Custom JSON Additions

In addition to the JSON additions provided, you can craft JSON additions of your own, either for Ruby built-in classes or for user-defined classes.

Here’s a user-defined class Foo:

class Foo
  attr_accessor :bar, :baz
  def initialize(bar, baz)
    self.bar = bar
    self.baz = baz
  end
end

Here’s the JSON addition for it:

# Extend class Foo with JSON addition.
class Foo
  # Serialize Foo object with its class name and arguments
  def to_json(*args)
    {
      JSON.create_id  => self.class.name,
      'a'             => [ bar, baz ]
    }.to_json(*args)
  end
  # Deserialize JSON string by constructing new Foo object with arguments.
  def self.json_create(object)
    new(*object['a'])
  end
end

Demonstration:

require 'json'
# This Foo object has no custom addition.
foo0 = Foo.new(0, 1)
json0 = JSON.generate(foo0)
obj0 = JSON.parse(json0)
# Lood the custom addition.
require_relative 'foo_addition'
# This foo has the custom addition.
foo1 = Foo.new(0, 1)
json1 = JSON.generate(foo1)
obj1 = JSON.parse(json1, create_additions: true)
#   Make a nice display.
display = <<EOT
Generated JSON:
  Without custom addition:  #{json0} (#{json0.class})
  With custom addition:     #{json1} (#{json1.class})
Parsed JSON:
  Without custom addition:  #{obj0.inspect} (#{obj0.class})
  With custom addition:     #{obj1.inspect} (#{obj1.class})
EOT
puts display

Output:

Generated JSON:
  Without custom addition:  "#<Foo:0x0000000006534e80>" (String)
  With custom addition:     {"json_class":"Foo","a":[0,1]} (String)
Parsed JSON:
  Without custom addition:  "#<Foo:0x0000000006534e80>" (String)
  With custom addition:     #<Foo:0x0000000006473bb8 @bar=0, @baz=1> (Foo)
No documentation available

Kanji Converter for Ruby.

The objspace library extends the ObjectSpace module and adds several methods to get internal statistic information about object/memory management.

You need to require 'objspace' to use this extension module.

Generally, you *SHOULD NOT* use this library if you do not know about the MRI implementation. Mainly, this library is for (memory) profiler developers and MRI developers who need to know about MRI memory usage.

The ObjectSpace module contains a number of routines that interact with the garbage collection facility and allow you to traverse all living objects with an iterator.

ObjectSpace also provides support for object finalizers, procs that will be called when a specific object is about to be destroyed by garbage collection. See the documentation for ObjectSpace.define_finalizer for important information on how to use this method correctly.

a = "A"
b = "B"

ObjectSpace.define_finalizer(a, proc {|id| puts "Finalizer one on #{id}" })
ObjectSpace.define_finalizer(b, proc {|id| puts "Finalizer two on #{id}" })

a = nil
b = nil

produces:

Finalizer two on 537763470
Finalizer one on 537763480

OpenSSL provides SSL, TLS and general purpose cryptography. It wraps the OpenSSL library.

Examples

All examples assume you have loaded OpenSSL with:

require 'openssl'

These examples build atop each other. For example the key created in the next is used in throughout these examples.

Keys

Creating a Key

This example creates a 2048 bit RSA keypair and writes it to the current directory.

key = OpenSSL::PKey::RSA.new 2048

open 'private_key.pem', 'w' do |io| io.write key.to_pem end
open 'public_key.pem', 'w' do |io| io.write key.public_key.to_pem end

Exporting a Key

Keys saved to disk without encryption are not secure as anyone who gets ahold of the key may use it unless it is encrypted. In order to securely export a key you may export it with a pass phrase.

cipher = OpenSSL::Cipher.new 'aes-256-cbc'
pass_phrase = 'my secure pass phrase goes here'

key_secure = key.export cipher, pass_phrase

open 'private.secure.pem', 'w' do |io|
  io.write key_secure
end

OpenSSL::Cipher.ciphers returns a list of available ciphers.

Loading a Key

A key can also be loaded from a file.

key2 = OpenSSL::PKey.read File.read 'private_key.pem'
key2.public? # => true
key2.private? # => true

or

key3 = OpenSSL::PKey.read File.read 'public_key.pem'
key3.public? # => true
key3.private? # => false

Loading an Encrypted Key

OpenSSL will prompt you for your pass phrase when loading an encrypted key. If you will not be able to type in the pass phrase you may provide it when loading the key:

key4_pem = File.read 'private.secure.pem'
pass_phrase = 'my secure pass phrase goes here'
key4 = OpenSSL::PKey.read key4_pem, pass_phrase

RSA Encryption

RSA provides encryption and decryption using the public and private keys. You can use a variety of padding methods depending upon the intended use of encrypted data.

Encryption & Decryption

Asymmetric public/private key encryption is slow and victim to attack in cases where it is used without padding or directly to encrypt larger chunks of data. Typical use cases for RSA encryption involve “wrapping” a symmetric key with the public key of the recipient who would “unwrap” that symmetric key again using their private key. The following illustrates a simplified example of such a key transport scheme. It shouldn’t be used in practice, though, standardized protocols should always be preferred.

wrapped_key = key.public_encrypt key

A symmetric key encrypted with the public key can only be decrypted with the corresponding private key of the recipient.

original_key = key.private_decrypt wrapped_key

By default PKCS#1 padding will be used, but it is also possible to use other forms of padding, see PKey::RSA for further details.

Signatures

Using “private_encrypt” to encrypt some data with the private key is equivalent to applying a digital signature to the data. A verifying party may validate the signature by comparing the result of decrypting the signature with “public_decrypt” to the original data. However, OpenSSL::PKey already has methods “sign” and “verify” that handle digital signatures in a standardized way - “private_encrypt” and “public_decrypt” shouldn’t be used in practice.

To sign a document, a cryptographically secure hash of the document is computed first, which is then signed using the private key.

signature = key.sign 'SHA256', document

To validate the signature, again a hash of the document is computed and the signature is decrypted using the public key. The result is then compared to the hash just computed, if they are equal the signature was valid.

if key.verify 'SHA256', signature, document
  puts 'Valid'
else
  puts 'Invalid'
end

PBKDF2 Password-based Encryption

If supported by the underlying OpenSSL version used, Password-based Encryption should use the features of PKCS5. If not supported or if required by legacy applications, the older, less secure methods specified in RFC 2898 are also supported (see below).

PKCS5 supports PBKDF2 as it was specified in PKCS#5 v2.0. It still uses a password, a salt, and additionally a number of iterations that will slow the key derivation process down. The slower this is, the more work it requires being able to brute-force the resulting key.

Encryption

The strategy is to first instantiate a Cipher for encryption, and then to generate a random IV plus a key derived from the password using PBKDF2. PKCS #5 v2.0 recommends at least 8 bytes for the salt, the number of iterations largely depends on the hardware being used.

cipher = OpenSSL::Cipher.new 'aes-256-cbc'
cipher.encrypt
iv = cipher.random_iv

pwd = 'some hopefully not to easily guessable password'
salt = OpenSSL::Random.random_bytes 16
iter = 20000
key_len = cipher.key_len
digest = OpenSSL::Digest.new('SHA256')

key = OpenSSL::PKCS5.pbkdf2_hmac(pwd, salt, iter, key_len, digest)
cipher.key = key

Now encrypt the data:

encrypted = cipher.update document
encrypted << cipher.final

Decryption

Use the same steps as before to derive the symmetric AES key, this time setting the Cipher up for decryption.

cipher = OpenSSL::Cipher.new 'aes-256-cbc'
cipher.decrypt
cipher.iv = iv # the one generated with #random_iv

pwd = 'some hopefully not to easily guessable password'
salt = ... # the one generated above
iter = 20000
key_len = cipher.key_len
digest = OpenSSL::Digest.new('SHA256')

key = OpenSSL::PKCS5.pbkdf2_hmac(pwd, salt, iter, key_len, digest)
cipher.key = key

Now decrypt the data:

decrypted = cipher.update encrypted
decrypted << cipher.final

PKCS #5 Password-based Encryption

PKCS #5 is a password-based encryption standard documented at RFC2898. It allows a short password or passphrase to be used to create a secure encryption key. If possible, PBKDF2 as described above should be used if the circumstances allow it.

PKCS #5 uses a Cipher, a pass phrase and a salt to generate an encryption key.

pass_phrase = 'my secure pass phrase goes here'
salt = '8 octets'

Encryption

First set up the cipher for encryption

encryptor = OpenSSL::Cipher.new 'aes-256-cbc'
encryptor.encrypt
encryptor.pkcs5_keyivgen pass_phrase, salt

Then pass the data you want to encrypt through

encrypted = encryptor.update 'top secret document'
encrypted << encryptor.final

Decryption

Use a new Cipher instance set up for decryption

decryptor = OpenSSL::Cipher.new 'aes-256-cbc'
decryptor.decrypt
decryptor.pkcs5_keyivgen pass_phrase, salt

Then pass the data you want to decrypt through

plain = decryptor.update encrypted
plain << decryptor.final

X509 Certificates

Creating a Certificate

This example creates a self-signed certificate using an RSA key and a SHA1 signature.

key = OpenSSL::PKey::RSA.new 2048
name = OpenSSL::X509::Name.parse '/CN=nobody/DC=example'

cert = OpenSSL::X509::Certificate.new
cert.version = 2
cert.serial = 0
cert.not_before = Time.now
cert.not_after = Time.now + 3600

cert.public_key = key.public_key
cert.subject = name

Certificate Extensions

You can add extensions to the certificate with OpenSSL::SSL::ExtensionFactory to indicate the purpose of the certificate.

extension_factory = OpenSSL::X509::ExtensionFactory.new nil, cert

cert.add_extension \
  extension_factory.create_extension('basicConstraints', 'CA:FALSE', true)

cert.add_extension \
  extension_factory.create_extension(
    'keyUsage', 'keyEncipherment,dataEncipherment,digitalSignature')

cert.add_extension \
  extension_factory.create_extension('subjectKeyIdentifier', 'hash')

The list of supported extensions (and in some cases their possible values) can be derived from the “objects.h” file in the OpenSSL source code.

Signing a Certificate

To sign a certificate set the issuer and use OpenSSL::X509::Certificate#sign with a digest algorithm. This creates a self-signed cert because we’re using the same name and key to sign the certificate as was used to create the certificate.

cert.issuer = name
cert.sign key, OpenSSL::Digest.new('SHA1')

open 'certificate.pem', 'w' do |io| io.write cert.to_pem end

Loading a Certificate

Like a key, a cert can also be loaded from a file.

cert2 = OpenSSL::X509::Certificate.new File.read 'certificate.pem'

Verifying a Certificate

Certificate#verify will return true when a certificate was signed with the given public key.

raise 'certificate can not be verified' unless cert2.verify key

Certificate Authority

A certificate authority (CA) is a trusted third party that allows you to verify the ownership of unknown certificates. The CA issues key signatures that indicate it trusts the user of that key. A user encountering the key can verify the signature by using the CA’s public key.

CA Key

CA keys are valuable, so we encrypt and save it to disk and make sure it is not readable by other users.

ca_key = OpenSSL::PKey::RSA.new 2048
pass_phrase = 'my secure pass phrase goes here'

cipher = OpenSSL::Cipher.new 'aes-256-cbc'

open 'ca_key.pem', 'w', 0400 do |io|
  io.write ca_key.export(cipher, pass_phrase)
end

CA Certificate

A CA certificate is created the same way we created a certificate above, but with different extensions.

ca_name = OpenSSL::X509::Name.parse '/CN=ca/DC=example'

ca_cert = OpenSSL::X509::Certificate.new
ca_cert.serial = 0
ca_cert.version = 2
ca_cert.not_before = Time.now
ca_cert.not_after = Time.now + 86400

ca_cert.public_key = ca_key.public_key
ca_cert.subject = ca_name
ca_cert.issuer = ca_name

extension_factory = OpenSSL::X509::ExtensionFactory.new
extension_factory.subject_certificate = ca_cert
extension_factory.issuer_certificate = ca_cert

ca_cert.add_extension \
  extension_factory.create_extension('subjectKeyIdentifier', 'hash')

This extension indicates the CA’s key may be used as a CA.

ca_cert.add_extension \
  extension_factory.create_extension('basicConstraints', 'CA:TRUE', true)

This extension indicates the CA’s key may be used to verify signatures on both certificates and certificate revocations.

ca_cert.add_extension \
  extension_factory.create_extension(
    'keyUsage', 'cRLSign,keyCertSign', true)

Root CA certificates are self-signed.

ca_cert.sign ca_key, OpenSSL::Digest.new('SHA1')

The CA certificate is saved to disk so it may be distributed to all the users of the keys this CA will sign.

open 'ca_cert.pem', 'w' do |io|
  io.write ca_cert.to_pem
end

Certificate Signing Request

The CA signs keys through a Certificate Signing Request (CSR). The CSR contains the information necessary to identify the key.

csr = OpenSSL::X509::Request.new
csr.version = 0
csr.subject = name
csr.public_key = key.public_key
csr.sign key, OpenSSL::Digest.new('SHA1')

A CSR is saved to disk and sent to the CA for signing.

open 'csr.pem', 'w' do |io|
  io.write csr.to_pem
end

Creating a Certificate from a CSR

Upon receiving a CSR the CA will verify it before signing it. A minimal verification would be to check the CSR’s signature.

csr = OpenSSL::X509::Request.new File.read 'csr.pem'

raise 'CSR can not be verified' unless csr.verify csr.public_key

After verification a certificate is created, marked for various usages, signed with the CA key and returned to the requester.

csr_cert = OpenSSL::X509::Certificate.new
csr_cert.serial = 0
csr_cert.version = 2
csr_cert.not_before = Time.now
csr_cert.not_after = Time.now + 600

csr_cert.subject = csr.subject
csr_cert.public_key = csr.public_key
csr_cert.issuer = ca_cert.subject

extension_factory = OpenSSL::X509::ExtensionFactory.new
extension_factory.subject_certificate = csr_cert
extension_factory.issuer_certificate = ca_cert

csr_cert.add_extension \
  extension_factory.create_extension('basicConstraints', 'CA:FALSE')

csr_cert.add_extension \
  extension_factory.create_extension(
    'keyUsage', 'keyEncipherment,dataEncipherment,digitalSignature')

csr_cert.add_extension \
  extension_factory.create_extension('subjectKeyIdentifier', 'hash')

csr_cert.sign ca_key, OpenSSL::Digest.new('SHA1')

open 'csr_cert.pem', 'w' do |io|
  io.write csr_cert.to_pem
end

SSL and TLS Connections

Using our created key and certificate we can create an SSL or TLS connection. An SSLContext is used to set up an SSL session.

context = OpenSSL::SSL::SSLContext.new

SSL Server

An SSL server requires the certificate and private key to communicate securely with its clients:

context.cert = cert
context.key = key

Then create an SSLServer with a TCP server socket and the context. Use the SSLServer like an ordinary TCP server.

require 'socket'

tcp_server = TCPServer.new 5000
ssl_server = OpenSSL::SSL::SSLServer.new tcp_server, context

loop do
  ssl_connection = ssl_server.accept

  data = ssl_connection.gets

  response = "I got #{data.dump}"
  puts response

  ssl_connection.puts "I got #{data.dump}"
  ssl_connection.close
end

SSL client

An SSL client is created with a TCP socket and the context. SSLSocket#connect must be called to initiate the SSL handshake and start encryption. A key and certificate are not required for the client socket.

Note that SSLSocket#close doesn’t close the underlying socket by default. Set SSLSocket#sync_close to true if you want.

require 'socket'

tcp_socket = TCPSocket.new 'localhost', 5000
ssl_client = OpenSSL::SSL::SSLSocket.new tcp_socket, context
ssl_client.sync_close = true
ssl_client.connect

ssl_client.puts "hello server!"
puts ssl_client.gets

ssl_client.close # shutdown the TLS connection and close tcp_socket

Peer Verification

An unverified SSL connection does not provide much security. For enhanced security the client or server can verify the certificate of its peer.

The client can be modified to verify the server’s certificate against the certificate authority’s certificate:

context.ca_file = 'ca_cert.pem'
context.verify_mode = OpenSSL::SSL::VERIFY_PEER

require 'socket'

tcp_socket = TCPSocket.new 'localhost', 5000
ssl_client = OpenSSL::SSL::SSLSocket.new tcp_socket, context
ssl_client.connect

ssl_client.puts "hello server!"
puts ssl_client.gets

If the server certificate is invalid or context.ca_file is not set when verifying peers an OpenSSL::SSL::SSLError will be raised.

PTY

Creates and manages pseudo terminals (PTYs). See also en.wikipedia.org/wiki/Pseudo_terminal

PTY allows you to allocate new terminals using ::open or ::spawn a new terminal with a specific command.

Example

In this example we will change the buffering type in the factor command, assuming that factor uses stdio for stdout buffering.

If IO.pipe is used instead of PTY.open, this code deadlocks because factor’s stdout is fully buffered.

# start by requiring the standard library PTY
require 'pty'

master, slave = PTY.open
read, write = IO.pipe
pid = spawn("factor", :in=>read, :out=>slave)
read.close     # we dont need the read
slave.close    # or the slave

# pipe "42" to the factor command
write.puts "42"
# output the response from factor
p master.gets #=> "42: 2 3 7\n"

# pipe "144" to factor and print out the response
write.puts "144"
p master.gets #=> "144: 2 2 2 2 3 3\n"
write.close # close the pipe

# The result of read operation when pty slave is closed is platform
# dependent.
ret = begin
        master.gets     # FreeBSD returns nil.
      rescue Errno::EIO # GNU/Linux raises EIO.
        nil
      end
p ret #=> nil

License

© Copyright 1998 by Akinori Ito.

This software may be redistributed freely for this purpose, in full or in part, provided that this entire copyright notice is included on any copies of this software and applications and derivations thereof.

This software is provided on an “as is” basis, without warranty of any kind, either expressed or implied, as to any matter including, but not limited to warranty of fitness of purpose, or merchantability, or results obtained from use of this software.

The Base64 module provides for the encoding (encode64, strict_encode64, urlsafe_encode64) and decoding (decode64, strict_decode64, urlsafe_decode64) of binary data using a Base64 representation.

Example

A simple encoding and decoding.

require "base64"

enc   = Base64.encode64('Send reinforcements')
                    # -> "U2VuZCByZWluZm9yY2VtZW50cw==\n"
plain = Base64.decode64(enc)
                    # -> "Send reinforcements"

The purpose of using base64 to encode data is that it translates any binary data into purely printable characters.

The Benchmark module provides methods to measure and report the time used to execute Ruby code.

The result:

              user     system      total        real
for:      1.010000   0.000000   1.010000 (  1.015688)
times:    1.000000   0.000000   1.000000 (  1.003611)
upto:     1.030000   0.000000   1.030000 (  1.028098)
No documentation available

fileutils.rb

Copyright © 2000-2007 Minero Aoki

This program is free software. You can distribute/modify this program under the same terms of ruby.

module 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| block }
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(target, link, **options)
FileUtils.ln(targets, dir, **options)
FileUtils.ln_s(target, link, **options)
FileUtils.ln_s(targets, dir, **options)
FileUtils.ln_sf(target, link, **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, **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)

Possible options are:

:force

forced operation (rewrite files if exist, remove directories if not empty, etc.);

:verbose

print command to be run, in bash syntax, before performing it;

:preserve

preserve object’s group, user and modification time on copying;

:noop

no changes are made (usable in combination with :verbose which will print the command to run)

Each method documents the options that it honours. See also ::commands, ::options and ::options_of methods to introspect which command have which options.

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 keyword arguments:

FileUtils.copy_entry(src, dest, preserve = false, dereference_root = false, remove_destination = 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)

module 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.

module 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.

module 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.

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!"

Another example

You could use Forwardable as an alternative to inheritance, when you don’t want to inherit all methods from the superclass. For instance, here is how you might add a range of Array instance methods to a new class Queue:

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 = Thread::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

Notes

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.

OpenURI is an easy-to-use wrapper for Net::HTTP, Net::HTTPS and Net::FTP.

Example

It is possible to open an http, https or ftp URL as though it were a file:

URI.open("http://www.ruby-lang.org/") {|f|
  f.each_line {|line| p line}
}

The opened file has several getter methods for its meta-information, as follows, since it is extended by OpenURI::Meta.

URI.open("http://www.ruby-lang.org/en") {|f|
  f.each_line {|line| p line}
  p f.base_uri         # <URI::HTTP:0x40e6ef2 URL:http://www.ruby-lang.org/en/>
  p f.content_type     # "text/html"
  p f.charset          # "iso-8859-1"
  p f.content_encoding # []
  p f.last_modified    # Thu Dec 05 02:45:02 UTC 2002
}

Additional header fields can be specified by an optional hash argument.

URI.open("http://www.ruby-lang.org/en/",
  "User-Agent" => "Ruby/#{RUBY_VERSION}",
  "From" => "foo@bar.invalid",
  "Referer" => "http://www.ruby-lang.org/") {|f|
  # ...
}

The environment variables such as http_proxy, https_proxy and ftp_proxy are in effect by default. Here we disable proxy:

URI.open("http://www.ruby-lang.org/en/", :proxy => nil) {|f|
  # ...
}

See OpenURI::OpenRead.open and URI.open for more on available options.

URI objects can be opened in a similar way.

uri = URI.parse("http://www.ruby-lang.org/en/")
uri.open {|f|
  # ...
}

URI objects can be read directly. The returned string is also extended by OpenURI::Meta.

str = uri.read
p str.base_uri
Author

Tanaka Akira <akr@m17n.org>

No documentation available

The Singleton module implements the Singleton pattern.

Usage

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.

Implementation

This above is achieved by:

Singleton and Marshal

By default Singleton’s _dump(depth) returns the empty string. Marshalling by default will strip state information, e.g. instance variables 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"

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

Timeout long-running blocks

Synopsis

require 'timeout'
status = Timeout::timeout(5) {
  # Something that should be interrupted if it takes more than 5 seconds...
}

Description

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.

Copyright

© 2000 Network Applied Communication Laboratory, Inc.

Copyright

© 2000 Information-technology Promotion Agency, Japan

This is not an existing class, but documentation of the interface that Scheduler object should comply to in order to be used as argument to Fiber.scheduler and handle non-blocking fibers. See also the “Non-blocking fibers” section in Fiber class docs for explanations of some concepts.

Scheduler’s behavior and usage are expected to be as follows:

A typical implementation would probably rely for this closing loop on a gem like EventMachine or Async.

This way concurrent execution will be achieved transparently for every individual Fiber’s code.

Hook methods are:

When not specified otherwise, the hook implementations are mandatory: if they are not implemented, the methods trying to call hook will fail. To provide backward compatibility, in the future hooks will be optional (if they are not implemented, due to the scheduler being created for the older Ruby version, the code which needs this hook will not fail, and will just behave in a blocking fashion).

It is also strongly recommended that the scheduler implements the fiber method, which is delegated to by Fiber.schedule.

Sample toy implementation of the scheduler can be found in Ruby’s code, in test/fiber/scheduler.rb

A base class for objects representing a C union

The base exception for JSON errors.

This exception is raised if the nesting of parsed data structures is too deep.

This exception is raised if a generator or unparser error occurs.

This class is used as a return value from ObjectSpace::reachable_objects_from.

When ObjectSpace::reachable_objects_from returns an object with references to an internal object, an instance of this class is returned.

You can use the type method to check the type of the internal object.

Generic error, common for all classes under OpenSSL module

General error for openssl library configuration files. Including formatting, parsing errors, etc.

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