Returns true if the underlying file descriptor of ios will be closed automatically at its finalization, otherwise false.
Sets auto-close flag.
f = open("/dev/null") IO.for_fd(f.fileno) # ... f.gets # may cause Errno::EBADF f = open("/dev/null") IO.for_fd(f.fileno).autoclose = false # ... f.gets # won't cause Errno::EBADF
Returns true if object is an element of self, false otherwise:
(1..4).include?(2) # => true (1..4).include?(5) # => false (1..4).include?(4) # => true (1...4).include?(4) # => false ('a'..'d').include?('b') # => true ('a'..'d').include?('e') # => false ('a'..'d').include?('B') # => false ('a'..'d').include?('d') # => true ('a'...'d').include?('d') # => false
If begin and end are numeric, include? behaves like cover?
(1..3).include?(1.5) # => true (1..3).cover?(1.5) # => true
But when not numeric, the two methods may differ:
('a'..'d').include?('cc') # => false ('a'..'d').cover?('cc') # => true
Related: Range#cover?.
Range#member? is an alias for Range#include?.
Returns true if the given argument is within self, false otherwise.
With non-range argument object, evaluates with <= and <.
For range self with included end value (#exclude_end? == false), evaluates thus:
self.begin <= object <= self.end
Examples:
r = (1..4) r.cover?(1) # => true r.cover?(4) # => true r.cover?(0) # => false r.cover?(5) # => false r.cover?('foo') # => false r = ('a'..'d') r.cover?('a') # => true r.cover?('d') # => true r.cover?(' ') # => false r.cover?('e') # => false r.cover?(0) # => false
For range r with excluded end value (#exclude_end? == true), evaluates thus:
r.begin <= object < r.end
Examples:
r = (1...4) r.cover?(1) # => true r.cover?(3) # => true r.cover?(0) # => false r.cover?(4) # => false r.cover?('foo') # => false r = ('a'...'d') r.cover?('a') # => true r.cover?('c') # => true r.cover?(' ') # => false r.cover?('d') # => false r.cover?(0) # => false
With range argument range, compares the first and last elements of self and range:
r = (1..4) r.cover?(1..4) # => true r.cover?(0..4) # => false r.cover?(1..5) # => false r.cover?('a'..'d') # => false r = (1...4) r.cover?(1..3) # => true r.cover?(1..4) # => false
If begin and end are numeric, cover? behaves like include?
(1..3).cover?(1.5) # => true (1..3).include?(1.5) # => true
But when not numeric, the two methods may differ:
('a'..'d').cover?('cc') # => true ('a'..'d').include?('cc') # => false
Returns false if either:
The begin value of self is larger than its end value.
An internal call to <=> returns nil; that is, the operands are not comparable.
Beginless ranges cover all values of the same type before the end, excluding the end for exclusive ranges. Beginless ranges cover ranges that end before the end of the beginless range, or at the end of the beginless range for inclusive ranges.
(..2).cover?(1) # => true (..2).cover?(2) # => true (..2).cover?(3) # => false (...2).cover?(2) # => false (..2).cover?("2") # => false (..2).cover?(..2) # => true (..2).cover?(...2) # => true (..2).cover?(.."2") # => false (...2).cover?(..2) # => false
Endless ranges cover all values of the same type after the beginning. Endless exclusive ranges do not cover endless inclusive ranges.
(2..).cover?(1) # => false (2..).cover?(3) # => true (2...).cover?(3) # => true (2..).cover?(2) # => true (2..).cover?("2") # => false (2..).cover?(2..) # => true (2..).cover?(2...) # => true (2..).cover?("2"..) # => false (2...).cover?(2..) # => false (2...).cover?(3...) # => true (2...).cover?(3..) # => false (3..).cover?(2..) # => false
Ranges that are both beginless and endless cover all values and ranges, and return true for all arguments, with the exception that beginless and endless exclusive ranges do not cover endless inclusive ranges.
(nil...).cover?(Object.new) # => true (nil...).cover?(nil...) # => true (nil..).cover?(nil...) # => true (nil...).cover?(nil..) # => false (nil...).cover?(1..) # => false
Related: Range#include?.
Returns true if the set is a superset of the given set.
Returns true if the set and the given enumerable have at least one element in common.
Set[1, 2, 3].intersect? Set[4, 5] #=> false Set[1, 2, 3].intersect? Set[3, 4] #=> true Set[1, 2, 3].intersect? 4..5 #=> false Set[1, 2, 3].intersect? [3, 4] #=> true
Equivalent to Set#select!
Returns the member names of the Struct descendant as an array:
Customer = Struct.new(:name, :address, :zip) Customer.members # => [:name, :address, :zip]
With a block given, returns an array of values from self for which the block returns a truthy value:
Customer = Struct.new(:name, :address, :zip) joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) a = joe.select {|value| value.is_a?(String) } a # => ["Joe Smith", "123 Maple, Anytown NC"] a = joe.select {|value| value.is_a?(Integer) } a # => [12345]
With no block given, returns an Enumerator.
Struct#filter is an alias for Struct#select.
Returns the member names from self as an array:
Customer = Struct.new(:name, :address, :zip) Customer.new.members # => [:name, :address, :zip]
Related: to_a.
Callback invoked whenever a subclass of the current class is created.
Example:
class Foo def self.inherited(subclass) puts "New subclass: #{subclass}" end end class Bar < Foo end class Baz < Bar end
produces:
New subclass: Bar New subclass: Baz
Allocates space for a new object of class’s class and does not call initialize on the new instance. The returned object must be an instance of class.
klass = Class.new do def initialize(*args) @initialized = true end def initialized? @initialized || false end end klass.allocate.initialized? #=> false
Returns the superclass of class, or nil.
File.superclass #=> IO IO.superclass #=> Object Object.superclass #=> BasicObject class Foo; end class Bar < Foo; end Bar.superclass #=> Foo
Returns nil when the given class does not have a parent class:
BasicObject.superclass #=> nil
Returns or yields Pathname objects.
Pathname.glob("lib/i*.rb") #=> [#<Pathname:lib/ipaddr.rb>, #<Pathname:lib/irb.rb>]
See Dir.glob.
Returns the current working directory as a Pathname.
Pathname.getwd #=> #<Pathname:/home/zzak/projects/ruby>
See Dir.getwd.
Returns or yields Pathname objects.
Pathname("ruby-2.4.2").glob("R*.md") #=> [#<Pathname:ruby-2.4.2/README.md>, #<Pathname:ruby-2.4.2/README.ja.md>]
See Dir.glob. This method uses the base keyword argument of Dir.glob.
Return true if parsed source has errors.
Returns an array of interface addresses. An element of the array is an instance of Socket::Ifaddr.
This method can be used to find multicast-enabled interfaces:
pp Socket.getifaddrs.reject {|ifaddr| !ifaddr.addr.ip? || (ifaddr.flags & Socket::IFF_MULTICAST == 0) }.map {|ifaddr| [ifaddr.name, ifaddr.ifindex, ifaddr.addr] } #=> [["eth0", 2, #<Addrinfo: 221.186.184.67>], # ["eth0", 2, #<Addrinfo: fe80::216:3eff:fe95:88bb%eth0>]]
Example result on GNU/Linux:
pp Socket.getifaddrs #=> [#<Socket::Ifaddr lo UP,LOOPBACK,RUNNING,0x10000 PACKET[protocol=0 lo hatype=772 HOST hwaddr=00:00:00:00:00:00]>, # #<Socket::Ifaddr eth0 UP,BROADCAST,RUNNING,MULTICAST,0x10000 PACKET[protocol=0 eth0 hatype=1 HOST hwaddr=00:16:3e:95:88:bb] broadcast=PACKET[protocol=0 eth0 hatype=1 HOST hwaddr=ff:ff:ff:ff:ff:ff]>, # #<Socket::Ifaddr sit0 NOARP PACKET[protocol=0 sit0 hatype=776 HOST hwaddr=00:00:00:00]>, # #<Socket::Ifaddr lo UP,LOOPBACK,RUNNING,0x10000 127.0.0.1 netmask=255.0.0.0>, # #<Socket::Ifaddr eth0 UP,BROADCAST,RUNNING,MULTICAST,0x10000 221.186.184.67 netmask=255.255.255.240 broadcast=221.186.184.79>, # #<Socket::Ifaddr lo UP,LOOPBACK,RUNNING,0x10000 ::1 netmask=ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff>, # #<Socket::Ifaddr eth0 UP,BROADCAST,RUNNING,MULTICAST,0x10000 fe80::216:3eff:fe95:88bb%eth0 netmask=ffff:ffff:ffff:ffff::>]
Example result on FreeBSD:
pp Socket.getifaddrs #=> [#<Socket::Ifaddr usbus0 UP,0x10000 LINK[usbus0]>, # #<Socket::Ifaddr re0 UP,BROADCAST,RUNNING,MULTICAST,0x800 LINK[re0 3a:d0:40:9a:fe:e8]>, # #<Socket::Ifaddr re0 UP,BROADCAST,RUNNING,MULTICAST,0x800 10.250.10.18 netmask=255.255.255.? (7 bytes for 16 bytes sockaddr_in) broadcast=10.250.10.255>, # #<Socket::Ifaddr re0 UP,BROADCAST,RUNNING,MULTICAST,0x800 fe80:2::38d0:40ff:fe9a:fee8 netmask=ffff:ffff:ffff:ffff::>, # #<Socket::Ifaddr re0 UP,BROADCAST,RUNNING,MULTICAST,0x800 2001:2e8:408:10::12 netmask=UNSPEC>, # #<Socket::Ifaddr plip0 POINTOPOINT,MULTICAST,0x800 LINK[plip0]>, # #<Socket::Ifaddr lo0 UP,LOOPBACK,RUNNING,MULTICAST LINK[lo0]>, # #<Socket::Ifaddr lo0 UP,LOOPBACK,RUNNING,MULTICAST ::1 netmask=ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff>, # #<Socket::Ifaddr lo0 UP,LOOPBACK,RUNNING,MULTICAST fe80:4::1 netmask=ffff:ffff:ffff:ffff::>, # #<Socket::Ifaddr lo0 UP,LOOPBACK,RUNNING,MULTICAST 127.0.0.1 netmask=255.?.?.? (5 bytes for 16 bytes sockaddr_in)>]