Waits until IO
is writable and returns a truthy value or a falsy value when times out.
You must require ‘io/wait’ to use this method.
Returns the Encoding
object that represents the encoding of the stream, or nil
if the stream is in write mode and no encoding is specified.
See Encodings.
Returns the Encoding
object that represents the encoding of the internal string, if conversion is specified, or nil
otherwise.
See Encodings.
Returns an array of values from self
.
With integer arguments integers
given, returns an array containing each value given by one of integers
:
Customer = Struct.new(:name, :address, :zip) joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) joe.values_at(0, 2) # => ["Joe Smith", 12345] joe.values_at(2, 0) # => [12345, "Joe Smith"] joe.values_at(2, 1, 0) # => [12345, "123 Maple, Anytown NC", "Joe Smith"] joe.values_at(0, -3) # => ["Joe Smith", "Joe Smith"]
Raises IndexError
if any of integers
is out of range; see Array Indexes at Array
.
With integer range argument integer_range
given, returns an array containing each value given by the elements of the range; fills with nil
values for range elements larger than the structure:
joe.values_at(0..2) # => ["Joe Smith", "123 Maple, Anytown NC", 12345] joe.values_at(-3..-1) # => ["Joe Smith", "123 Maple, Anytown NC", 12345] joe.values_at(1..4) # => ["123 Maple, Anytown NC", 12345, nil, nil]
Raises RangeError
if any element of the range is negative and out of range; see Array Indexes at Array
.
Equivalent to self.to_s.start_with?
; see String#start_with?
.
Returns an Addrinfo
object for local address obtained by getsockname.
Note that addrinfo.protocol is filled by 0.
TCPSocket.open("www.ruby-lang.org", 80) {|s| p s.local_address #=> #<Addrinfo: 192.168.0.129:36873 TCP> } TCPServer.open("127.0.0.1", 1512) {|serv| p serv.local_address #=> #<Addrinfo: 127.0.0.1:1512 TCP> }
creates an Addrinfo
object from the arguments.
The arguments are interpreted as similar to self.
Addrinfo.tcp("0.0.0.0", 4649).family_addrinfo("www.ruby-lang.org", 80) #=> #<Addrinfo: 221.186.184.68:80 TCP (www.ruby-lang.org:80)> Addrinfo.unix("/tmp/sock").family_addrinfo("/tmp/sock2") #=> #<Addrinfo: /tmp/sock2 SOCK_STREAM>
creates a new Socket
connected to the address of local_addrinfo
.
If local_addrinfo is nil, the address of the socket is not bound.
The timeout specify the seconds for timeout. Errno::ETIMEDOUT is raised when timeout occur.
If a block is given the created socket is yielded for each address.
Returns true for IPv6 link local address (fe80::/10). It returns false otherwise.
Returns true for IPv6 site local address (fec0::/10). It returns false otherwise.
Returns the Encoding
object that represents the encoding of the file. If the stream is write mode and no encoding is specified, returns nil
.
Returns the Encoding
of the internal string if conversion is specified. Otherwise returns nil
.
Returns a shallow copy of self
; the [stored string] in the copy is the same string as in self
.
Returns an array of captured substrings, or nil
of none.
For each specifier
, the returned substring is [specifier]
; see []
.
scanner = StringScanner.new('Fri Dec 12 1975 14:39') pattern = /(?<wday>\w+) (?<month>\w+) (?<day>\d+) / scanner.match?(pattern) scanner.values_at(*0..3) # => ["Fri Dec 12 ", "Fri", "Dec", "12"] scanner.values_at(*%i[wday month day]) # => ["Fri", "Dec", "12"]
Executes the given block within the context of the receiver (obj). In order to set the context, the variable self
is set to obj while the code is executing, giving the code access to obj’s instance variables. Arguments are passed as block parameters.
class KlassWithSecret def initialize @secret = 99 end end k = KlassWithSecret.new k.instance_exec(5) {|x| @secret+x } #=> 104
Replaces the entire contents of self
with the contents of other_hash
; returns self
:
h = {foo: 0, bar: 1, baz: 2} h.replace({bat: 3, bam: 4}) # => {bat: 3, bam: 4}
Related: see Methods for Assigning.
With a block given, calls the block with each value; returns self
:
h = {foo: 0, bar: 1, baz: 2} h.each_value {|value| puts value } # => {foo: 0, bar: 1, baz: 2}
Output:
0 1 2
With no block given, returns a new Enumerator
.
Related: see Methods for Iterating.
With a block given, returns a new hash new_hash
; for each pair key
/value
in self
, calls the block with value
and captures its return as new_value
; adds to new_hash
the entry key
/new_value
:
h = {foo: 0, bar: 1, baz: 2} h1 = h.transform_values {|value| value * 100} h1 # => {foo: 0, bar: 100, baz: 200}
With no block given, returns a new Enumerator
.
Related: see Methods for Transforming Keys and Values.
With a block given, changes the values of self
as determined by the block; returns self
.
For each entry key
/old_value
in self
, calls the block with old_value
, captures its return value as new_value
, and sets self[key] = new_value
:
h = {foo: 0, bar: 1, baz: 2} h.transform_values! {|value| value * 100} # => {foo: 0, bar: 100, baz: 200}
With no block given, returns a new Enumerator
.
Related: see Methods for Transforming Keys and Values.
Returns a new array containing values for the given keys
:
h = {foo: 0, bar: 1, baz: 2} h.values_at(:baz, :foo) # => [2, 0]
The hash default is returned for each key that is not found:
h.values_at(:hello, :foo) # => [nil, 0]
Related: see Methods for Fetching.