Returns true if range overlaps with self, false otherwise:
(0..2).overlap?(1..3) #=> true (0..2).overlap?(3..4) #=> false (0..).overlap?(..0) #=> true
With non-range argument, raises TypeError.
(1..3).overlap?(1) # TypeError
Returns false if an internal call to <=> returns nil; that is, the operands are not comparable.
(1..3).overlap?('a'..'d') # => false
Returns false if self or range is empty. “Empty range” means that its begin value is larger than, or equal for an exclusive range, its end value.
(4..1).overlap?(2..3) # => false (4..1).overlap?(..3) # => false (4..1).overlap?(2..) # => false (2...2).overlap?(1..2) # => false (1..4).overlap?(3..2) # => false (..4).overlap?(3..2) # => false (1..).overlap?(3..2) # => false (1..2).overlap?(2...2) # => false
Returns false if the begin value one of self and range is larger than, or equal if the other is an exclusive range, the end value of the other:
(4..5).overlap?(2..3) # => false (4..5).overlap?(2...4) # => false (1..2).overlap?(3..4) # => false (1...3).overlap?(3..4) # => false
Returns false if the end value one of self and range is larger than, or equal for an exclusive range, the end value of the other:
(4..5).overlap?(2..3) # => false (4..5).overlap?(2...4) # => false (1..2).overlap?(3..4) # => false (1...3).overlap?(3..4) # => false
Note that the method wouldn’t make any assumptions about the beginless range being actually empty, even if its upper bound is the minimum possible value of its type, so all this would return true:
(...-Float::INFINITY).overlap?(...-Float::INFINITY) # => true (..."").overlap?(..."") # => true (...[]).overlap?(...[]) # => true
Even if those ranges are effectively empty (no number can be smaller than -Float::INFINITY), they are still considered overlapping with themselves.
Related: Range#cover?.
Returns the numerator.
Rational(7).numerator #=> 7 Rational(7, 1).numerator #=> 7 Rational(9, -4).numerator #=> -9 Rational(-2, -10).numerator #=> 1
Returns the largest number less than or equal to rat with a precision of ndigits decimal digits (default: 0).
When the precision is negative, the returned value is an integer with at least ndigits.abs trailing zeros.
Returns a rational when ndigits is positive, otherwise returns an integer.
Rational(3).floor #=> 3 Rational(2, 3).floor #=> 0 Rational(-3, 2).floor #=> -2 # decimal - 1 2 3 . 4 5 6 # ^ ^ ^ ^ ^ ^ # precision -3 -2 -1 0 +1 +2 Rational('-123.456').floor(+1).to_f #=> -123.5 Rational('-123.456').floor(-1) #=> -130
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.
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.
Spawns the specified command on a newly allocated pty. You can also use the alias ::getpty.
The command’s controlling tty is set to the slave device of the pty and its standard input/output/error is redirected to the slave device.
env is an optional hash that provides additional environment variables to the spawned pty.
# sets FOO to "bar" PTY.spawn({"FOO"=>"bar"}, "printenv", "FOO") { |r,w,pid| p r.read } #=> "bar\r\n" # unsets FOO PTY.spawn({"FOO"=>nil}, "printenv", "FOO") { |r,w,pid| p r.read } #=> ""
command and command_line are the full commands to run, given a String. Any additional arguments will be passed to the command.
In the non-block form this returns an array of size three, [r, w, pid].
In the block form these same values will be yielded to the block:
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)>]
Returns the hostname.
p Socket.gethostname #=> "hal"
Note that it is not guaranteed to be able to convert to IP address using gethostbyname, getaddrinfo, etc. If you need local IP address, use Socket.ip_address_list.