Returns true if ios is completely closed (for duplex streams, both reader and writer), false otherwise.
f = File.new("testfile") f.close #=> nil f.closed? #=> true f = IO.popen("/bin/sh","r+") f.close_write #=> nil f.closed? #=> false f.close_read #=> nil f.closed? #=> true
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
Closes the associated database file.
Returns true if the associated database file has been closed.
Returns a hash created by using gdbm’s values as keys, and the keys as values.
Returns true if the given key k exists within the database. Returns false otherwise.
Returns true if obj is an element of the range, false otherwise.
("a".."z").include?("g") #=> true ("a".."z").include?("A") #=> false ("a".."z").include?("cc") #=> false
If you need to ensure obj is between begin and end, use cover?
("a".."z").cover?("cc") #=> true
If begin and end are numeric, include? behaves like cover?
(1..3).include?(1.5) # => true
Returns true if obj is between the begin and end of the range.
This tests begin <= obj <= end when exclude_end? is false and begin <= obj < end when exclude_end? is true.
If called with a Range argument, returns true when the given range is covered by the receiver, by comparing the begin and end values. If the argument can be treated as a sequence, this method treats it that way. In the specific case of (a..b).cover?(c...d) with a <= c && b < d, the end of the sequence must be calculated, which may exhibit poor performance if c is non-numeric. Returns false if the begin value of the range is larger than the end value. Also returns false if one of the internal calls to <=> returns nil (indicating the objects are not comparable).
("a".."z").cover?("c") #=> true ("a".."z").cover?("5") #=> false ("a".."z").cover?("cc") #=> true ("a".."z").cover?(1) #=> false (1..5).cover?(2..3) #=> true (1..5).cover?(0..6) #=> false (1..5).cover?(1...6) #=> true
Returns true if the set is a superset of the given set.
Returns true if the set and the given set 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
Equivalent to Set#select!
In general, to_sym returns the Symbol corresponding to an object. As sym is already a symbol, self is returned in this case.
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.