Results for: "Dir.chdir"

Performs division and returns the value as a Float.

Rational(2, 3).fdiv(1)       #=> 0.6666666666666666
Rational(2, 3).fdiv(0.5)     #=> 1.3333333333333333
Rational(2).fdiv(3)          #=> 0.6666666666666666

Creates a date object denoting the given ordinal date.

The day of year should be a negative or a positive number (as a relative day from the end of year when negative). It should not be zero.

Date.ordinal(2001)        #=> #<Date: 2001-01-01 ...>
Date.ordinal(2001,34)     #=> #<Date: 2001-02-03 ...>
Date.ordinal(2001,-1)     #=> #<Date: 2001-12-31 ...>

See also ::jd and ::new.

Creates a DateTime object denoting the given ordinal date.

DateTime.ordinal(2001,34) #=> #<DateTime: 2001-02-03T00:00:00+00:00 ...>
DateTime.ordinal(2001,34,4,5,6,'+7')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.ordinal(2001,-332,-20,-55,-54,'+7')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>

Extracts the nested value specified by the sequence of key objects by calling dig at each step, returning nil if any intermediate step is nil.

Foo = Struct.new(:a)
f = Foo.new(Foo.new({b: [1, 2, 3]}))

f.dig(:a, :a, :b, 0)    # => 1
f.dig(:b, 0)            # => nil
f.dig(:a, :a, :b, :c)   # TypeError: no implicit conversion of Symbol into Integer

Extracts the nested value specified by the sequence of name objects by calling dig at each step, returning nil if any intermediate step is nil.

require "ostruct"
address = OpenStruct.new("city" => "Anytown NC", "zip" => 12345)
person  = OpenStruct.new("name" => "John Smith", "address" => address)

person.dig(:address, "zip")            # => 12345
person.dig(:business_address, "zip")   # => nil

data = OpenStruct.new(:array => [1, [2, 3]])

data.dig(:array, 1, 0)   # => 2
data.dig(:array, 0, 0)   # TypeError: Integer does not have #dig method

Returns the first object in the range, or an array of the first n elements.

(10..20).first     #=> 10
(10..20).first(3)  #=> [10, 11, 12]

Returns the Encoding object that represents the encoding of obj.

Returns true if the set and the given set have no element in common. This method is the opposite of intersect?.

Set[1, 2, 3].disjoint? Set[3, 4]   #=> false
Set[1, 2, 3].disjoint? Set[4, 5]   #=> true

Divides the set into a set of subsets according to the commonality defined by the given block.

If the arity of the block is 2, elements o1 and o2 are in common if block.call(o1, o2) is true. Otherwise, elements o1 and o2 are in common if block.call(o1) == block.call(o2).

require 'set'
numbers = Set[1, 3, 4, 6, 9, 10, 11]
set = numbers.divide { |i,j| (i - j).abs == 1 }
set        #=> #<Set: {#<Set: {1}>,
           #           #<Set: {11, 9, 10}>,
           #           #<Set: {3, 4}>,
           #           #<Set: {6}>}>

Returns an enumerator if no block is given.

Returns the Encoding object that represents the encoding of sym.

Returns the birth time for the file. If the platform doesn’t have birthtime, raises NotImplementedError.

See File.birthtime.

Return encoding of the source.

Creates a pair of sockets connected each other.

domain should be a communications domain such as: :INET, :INET6, :UNIX, etc.

socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.

protocol should be a protocol defined in the domain, defaults to 0 for the domain.

s1, s2 = Socket.pair(:UNIX, :STREAM, 0)
s1.send "a", 0
s1.send "b", 0
s1.close
p s2.recv(10) #=> "ab"
p s2.recv(10) #=> ""
p s2.recv(10) #=> ""

s1, s2 = Socket.pair(:UNIX, :DGRAM, 0)
s1.send "a", 0
s1.send "b", 0
p s2.recv(10) #=> "a"
p s2.recv(10) #=> "b"

Creates a pair of sockets connected each other.

domain should be a communications domain such as: :INET, :INET6, :UNIX, etc.

socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.

protocol should be a protocol defined in the domain, defaults to 0 for the domain.

s1, s2 = Socket.pair(:UNIX, :STREAM, 0)
s1.send "a", 0
s1.send "b", 0
s1.close
p s2.recv(10) #=> "ab"
p s2.recv(10) #=> ""
p s2.recv(10) #=> ""

s1, s2 = Socket.pair(:UNIX, :DGRAM, 0)
s1.send "a", 0
s1.send "b", 0
p s2.recv(10) #=> "a"
p s2.recv(10) #=> "b"

Creates a pair of sockets connected to each other.

socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.

protocol should be a protocol defined in the domain. 0 is default protocol for the domain.

s1, s2 = UNIXSocket.pair
s1.send "a", 0
s1.send "b", 0
p s2.recv(10) #=> "ab"

Creates a pair of sockets connected to each other.

socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.

protocol should be a protocol defined in the domain. 0 is default protocol for the domain.

s1, s2 = UNIXSocket.pair
s1.send "a", 0
s1.send "b", 0
p s2.recv(10) #=> "ab"

Returns dispatch ID.

tobj = WIN32OLE_TYPE.new('Microsoft Excel 9.0 Object Library', 'Workbooks')
method = WIN32OLE_METHOD.new(tobj, 'Add')
puts method.dispid # => 181

Extracts the nested value specified by the sequence of key objects by calling dig at each step, returning nil if any intermediate step is nil.

h = { foo: {bar: {baz: 1}}}

h.dig(:foo, :bar, :baz)     #=> 1
h.dig(:foo, :zot, :xyz)     #=> nil

g = { foo: [10, 11, 12] }
g.dig(:foo, 1)              #=> 11
g.dig(:foo, 1, 0)           #=> TypeError: Integer does not have #dig method
g.dig(:foo, :bar)           #=> TypeError: no implicit conversion of Symbol into Integer

Synonym for $stdin.

Returns the display expression list

See DEBUGGER__ for more usage

Opens an IRB session where binding.irb is called which allows for interactive debugging. You can call any methods or variables available in the current scope, and mutate state if you need to.

Given a Ruby file called potato.rb containing the following code:

class Potato
  def initialize
    @cooked = false
    binding.irb
    puts "Cooked potato: #{@cooked}"
  end
end

Potato.new

Running ruby potato.rb will open an IRB session where binding.irb is called, and you will see the following:

$ ruby potato.rb

From: potato.rb @ line 4 :

    1: class Potato
    2:   def initialize
    3:     @cooked = false
 => 4:     binding.irb
    5:     puts "Cooked potato: #{@cooked}"
    6:   end
    7: end
    8:
    9: Potato.new

irb(#<Potato:0x00007feea1916670>):001:0>

You can type any valid Ruby code and it will be evaluated in the current context. This allows you to debug without having to run your code repeatedly:

irb(#<Potato:0x00007feea1916670>):001:0> @cooked
=> false
irb(#<Potato:0x00007feea1916670>):002:0> self.class
=> Potato
irb(#<Potato:0x00007feea1916670>):003:0> caller.first
=> ".../2.5.1/lib/ruby/2.5.0/irb/workspace.rb:85:in `eval'"
irb(#<Potato:0x00007feea1916670>):004:0> @cooked = true
=> true

You can exit the IRB session with the exit command. Note that exiting will resume execution where binding.irb had paused it, as you can see from the output printed to standard output in this example:

irb(#<Potato:0x00007feea1916670>):005:0> exit
Cooked potato: true

See IRB for more information.

Creates a matrix where the diagonal elements are composed of values.

Matrix.diagonal(9, 5, -3)
  =>  9  0  0
      0  5  0
      0  0 -3

Returns true if this is a diagonal matrix. Raises an error if matrix is not square.