return the JSON
value
Returns a hash, that will be turned into a JSON
object and represent this object.
Returns true
if the class was initialized with keyword_init: true
. Otherwise returns nil
or false
.
Examples:
Foo = Struct.new(:a) Foo.keyword_init? # => nil Bar = Struct.new(:a, keyword_init: true) Bar.keyword_init? # => true Baz = Struct.new(:a, keyword_init: false) Baz.keyword_init? # => false
Calls the given block with each member name/value pair; returns self
:
Customer = Struct.new(:name, :address, :zip) # => Customer joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) joe.each_pair {|(name, value)| p "#{name} => #{value}" }
Output:
"name => Joe Smith" "address => 123 Maple, Anytown NC" "zip => 12345"
Returns an Enumerator
if no block is given.
Related: each
.
Returns a hash of the name/value pairs for the given member names.
Customer = Struct.new(:name, :address, :zip) joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) h = joe.deconstruct_keys([:zip, :address]) h # => {:zip=>12345, :address=>"123 Maple, Anytown NC"}
Returns all names and values if array_of_names
is nil
:
h = joe.deconstruct_keys(nil) h # => {:name=>"Joseph Smith, Jr.", :address=>"123 Maple, Anytown NC", :zip=>12345}
Returns a hash, that will be turned into a JSON
object and represent this object.
Equivalent to self.to_s.end_with?
; see String#end_with?
.
Returns true if this class can be used to create an instance from a serialised JSON
string. The class has to implement a class method json_create that expects a hash as first parameter. The hash should include the required data.
Return the path as a String
.
to_path
is implemented so Pathname
objects are usable with File.open
, etc.
Receives up to maxlen bytes from socket
using recvfrom(2) after O_NONBLOCK is set for the underlying file descriptor. flags is zero or more of the MSG_
options. The first element of the results, mesg, is the data received. The second element, sender_addrinfo, contains protocol-specific address information of the sender.
When recvfrom(2) returns 0, Socket#recvfrom_nonblock
returns an empty string as data. The meaning depends on the socket: EOF on TCP, empty packet on UDP, etc.
maxlen
- the maximum number of bytes to receive from the socket
flags
- zero or more of the MSG_
options
outbuf
- destination String
buffer
opts
- keyword hash, supporting ‘exception: false`
# In one file, start this first require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.bind(sockaddr) socket.listen(5) client, client_addrinfo = socket.accept begin # emulate blocking recvfrom pair = client.recvfrom_nonblock(20) rescue IO::WaitReadable IO.select([client]) retry end data = pair[0].chomp puts "I only received 20 bytes '#{data}'" sleep 1 socket.close # In another file, start this second require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.connect(sockaddr) socket.puts "Watch this get cut short!" socket.close
Refer to Socket#recvfrom
for the exceptions that may be thrown if the call to recvfrom_nonblock fails.
Socket#recvfrom_nonblock
may raise any error corresponding to recvfrom(2) failure, including Errno::EWOULDBLOCK.
If the exception is Errno::EWOULDBLOCK or Errno::EAGAIN, it is extended by IO::WaitReadable
. So IO::WaitReadable
can be used to rescue the exceptions for retrying recvfrom_nonblock.
By specifying a keyword argument exception to false
, you can indicate that recvfrom_nonblock
should not raise an IO::WaitReadable
exception, but return the symbol :wait_readable
instead.
Accepts an incoming connection using accept(2) after O_NONBLOCK is set for the underlying file descriptor. It returns an array containing the accepted socket for the incoming connection, client_socket, and an Addrinfo
, client_addrinfo.
# In one script, start this first require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.bind(sockaddr) socket.listen(5) begin # emulate blocking accept client_socket, client_addrinfo = socket.accept_nonblock rescue IO::WaitReadable, Errno::EINTR IO.select([socket]) retry end puts "The client said, '#{client_socket.readline.chomp}'" client_socket.puts "Hello from script one!" socket.close # In another script, start this second require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.connect(sockaddr) socket.puts "Hello from script 2." puts "The server said, '#{socket.readline.chomp}'" socket.close
Refer to Socket#accept
for the exceptions that may be thrown if the call to accept_nonblock fails.
Socket#accept_nonblock
may raise any error corresponding to accept(2) failure, including Errno::EWOULDBLOCK.
If the exception is Errno::EWOULDBLOCK, Errno::EAGAIN, Errno::ECONNABORTED or Errno::EPROTO, it is extended by IO::WaitReadable
. So IO::WaitReadable
can be used to rescue the exceptions for retrying accept_nonblock.
By specifying a keyword argument exception to false
, you can indicate that accept_nonblock
should not raise an IO::WaitReadable
exception, but return the symbol :wait_readable
instead.
Disallows further write using shutdown system call.
UNIXSocket.pair {|s1, s2| s1.print "ping" s1.close_write p s2.read #=> "ping" s2.print "pong" s2.close p s1.read #=> "pong" }
Returns an address of the socket suitable for connect in the local machine.
This method returns self.local_address, except following condition.
IPv4 unspecified address (0.0.0.0) is replaced by IPv4 loopback address (127.0.0.1).
IPv6 unspecified address (::) is replaced by IPv6 loopback address (::1).
If the local address is not suitable for connect, SocketError
is raised. IPv4 and IPv6 address which port is 0 is not suitable for connect. Unix domain socket which has no path is not suitable for connect.
Addrinfo.tcp("0.0.0.0", 0).listen {|serv| p serv.connect_address #=> #<Addrinfo: 127.0.0.1:53660 TCP> serv.connect_address.connect {|c| s, _ = serv.accept p [c, s] #=> [#<Socket:fd 4>, #<Socket:fd 6>] } }
sendmsg_nonblock
sends a message using sendmsg(2) system call in non-blocking manner.
It is similar to BasicSocket#sendmsg
but the non-blocking flag is set before the system call and it doesn’t retry the system call.
By specifying a keyword argument exception to false
, you can indicate that sendmsg_nonblock
should not raise an IO::WaitWritable
exception, but return the symbol :wait_writable
instead.