class Socket

Included Modules

Direct Known Subclasses

Defined in:

socket.cr
socket/address.cr
socket/addrinfo.cr
socket/common.cr
socket/server.cr

Constructors

Class Method Summary

Instance Method Summary

Class methods inherited from module Crystal::System::Socket

fcntl(fd, cmd, arg = 0) fcntl, socketpair(type : ::Socket::Type, protocol : ::Socket::Protocol) : Tuple(Handle, Handle) socketpair

Instance methods inherited from module IO::Evented

evented_close : Nil evented_close

Instance methods inherited from module IO::Buffered

buffer_size : Int32 buffer_size, buffer_size=(value) buffer_size=, close : Nil close, flush flush, flush_on_newline=(flush_on_newline) flush_on_newline=, flush_on_newline? : Bool flush_on_newline?, peek : Bytes peek, pos : Int64 pos, read(slice : Bytes) : Int32 read, read_buffering=(read_buffering) read_buffering=, read_buffering? : Bool read_buffering?, rewind rewind, sync=(sync) sync=, sync? : Bool sync?, unbuffered_close unbuffered_close, unbuffered_flush unbuffered_flush, unbuffered_read(slice : Bytes) unbuffered_read, unbuffered_rewind unbuffered_rewind, unbuffered_write(slice : Bytes) unbuffered_write, write(slice : Bytes) : Nil write

Instance methods inherited from class IO

<<(obj) : self <<, close close, closed? : Bool closed?, each_byte(&) : Nil
each_byte
each_byte
, each_char(&) : Nil
each_char
each_char
, each_line(*args, **options, &block : String -> ) : Nil
each_line(*args, **options)
each_line
, encoding : String encoding, flush flush, getb_to_end : Bytes getb_to_end, gets(limit : Int, chomp = false) : String | Nil
gets(delimiter : Char, limit : Int, chomp = false) : String | Nil
gets(delimiter : Char, chomp = false) : String | Nil
gets(delimiter : String, chomp = false) : String | Nil
gets(chomp = true) : String | Nil
gets
, gets_to_end : String gets_to_end, peek : Bytes | Nil peek, pos pos, pos=(value) pos=, print(obj : _) : Nil
print(*objects : _) : Nil
print
, printf(format_string, args : Array | Tuple) : Nil
printf(format_string, *args) : Nil
printf
, puts(string : String) : Nil
puts(obj : _) : Nil
puts : Nil
puts(*objects : _) : Nil
puts
, read(slice : Bytes) read, read_at(offset, bytesize, & : IO -> ) read_at, read_byte : UInt8 | Nil read_byte, read_bytes(type, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) read_bytes, read_char : Char | Nil read_char, read_fully(slice : Bytes) : Int32 read_fully, read_fully?(slice : Bytes) : Int32 | Nil read_fully?, read_line(*args, **options) : String read_line, read_string(bytesize : Int) : String read_string, read_utf8(slice : Bytes) read_utf8, read_utf8_byte : UInt8 | Nil read_utf8_byte, rewind rewind, seek(offset, whence : Seek = Seek::Set) seek, set_encoding(encoding : String, invalid : Symbol | Nil = nil) : Nil set_encoding, skip(bytes_count : Int) : Nil skip, skip_to_end : Nil skip_to_end, tell tell, tty? : Bool tty?, write(slice : Bytes) : Nil write, write_byte(byte : UInt8) : Nil write_byte, write_bytes(object, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) : Nil write_bytes, write_string(slice : Bytes) : Nil write_string, write_utf8(slice : Bytes) : Nil write_utf8

Class methods inherited from class IO

copy(src, dst, limit : Int) : Int64
copy(src, dst) : Int64
copy
, pipe(read_blocking = false, write_blocking = false) : Tuple(IO::FileDescriptor, IO::FileDescriptor)
pipe(read_blocking = false, write_blocking = false, &)
pipe
, same_content?(stream1 : IO, stream2 : IO) : Bool same_content?

Instance methods inherited from class Reference

==(other : self)
==(other : JSON::Any)
==(other : YAML::Any)
==(other)
==
, dup dup, hash(hasher) hash, initialize initialize, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference) : Bool
same?(other : Nil)
same?
, to_s(io : IO) : Nil to_s

Constructor methods inherited from class Reference

new new, unsafe_construct(address : Pointer, *args, **opts) : self unsafe_construct

Class methods inherited from class Reference

pre_initialize(address : Pointer) pre_initialize

Instance methods inherited from class Object

! : Bool !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other)
===
, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash(hasher)
hash
hash
, in?(collection : Object) : Bool
in?(*values : Object) : Bool
in?
, inspect(io : IO) : Nil
inspect : String
inspect
, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil!(message)
not_nil!
not_nil!
, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) tap, to_json(io : IO) : Nil
to_json : String
to_json
, to_pretty_json(indent : String = " ") : String
to_pretty_json(io : IO, indent : String = " ") : Nil
to_pretty_json
, to_s(io : IO) : Nil
to_s : String
to_s
, to_yaml(io : IO) : Nil
to_yaml : String
to_yaml
, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

Class methods inherited from class Object

from_json(string_or_io, root : String)
from_json(string_or_io)
from_json
, from_yaml(string_or_io : String | IO) from_yaml

Macros inherited from class Object

class_getter(*names, &block) class_getter, class_getter!(*names) class_getter!, class_getter?(*names, &block) class_getter?, class_property(*names, &block) class_property, class_property!(*names) class_property!, class_property?(*names, &block) class_property?, class_setter(*names) class_setter, def_clone def_clone, def_equals(*fields) def_equals, def_equals_and_hash(*fields) def_equals_and_hash, def_hash(*fields) def_hash, delegate(*methods, to object) delegate, forward_missing_to(delegate) forward_missing_to, getter(*names, &block) getter, getter!(*names) getter!, getter?(*names, &block) getter?, property(*names, &block) property, property!(*names) property!, property?(*names, &block) property?, setter(*names) setter

Constructor Detail

def self.new(family : Family, type : Type, protocol : Protocol = Protocol::IP, blocking = false) #

def self.new(fd, family : Family, type : Type, protocol : Protocol = Protocol::IP, blocking = false) #

Creates a Socket from an existing socket file descriptor / handle.


def self.tcp(family : Family, blocking = false) : self #

Creates a TCP socket. Consider using TCPSocket or TCPServer unless you need full control over the socket.


def self.unix(type : Type = Type::STREAM, blocking = false) : self #

Creates an UNIX socket. Consider using UNIXSocket or UNIXServer unless you need full control over the socket.


Class Method Detail

def self.fcntl(fd, cmd, arg = 0) #

def self.ip?(string : String) #

Returns true if the string represents a valid IPv4 or IPv6 address.

DEPRECATED Use IPAddress.valid? instead


def self.udp(family : Family, blocking = false) #

Creates an UDP socket. Consider using UDPSocket unless you need full control over the socket.


Instance Method Detail

def accept : Socket #

Accepts an incoming connection.

Returns the client socket. Raises an IO::Error (closed stream) exception if the server is closed after invoking this method.

require "socket"

server = TCPServer.new(2202)
socket = server.accept
socket.puts Time.utc
socket.close

def accept? : Socket | Nil #

Accepts an incoming connection.

Returns the client Socket or nil if the server is closed after invoking this method.

require "socket"

server = TCPServer.new(2202)
if socket = server.accept?
  socket.puts Time.utc
  socket.close
end

def bind(host : String, port : Int) : Nil #

Binds the socket to a local address.

require "socket"

sock = Socket.tcp(Socket::Family::INET)
sock.bind "localhost", 1234

def bind(port : Int) #

Binds the socket on port to all local interfaces.

require "socket"

sock = Socket.tcp(Socket::Family::INET6)
sock.bind 1234

def bind(addr : Socket::Address) : Nil #

Binds the socket to a local address.

require "socket"

sock = Socket.udp(Socket::Family::INET)
sock.bind Socket::IPAddress.new("192.168.1.25", 80)

def blocking #

def blocking=(value) #

def broadcast=(val : Bool) #

def broadcast? : Bool #

def close_on_exec=(arg : Bool) #

def close_on_exec? #

def close_read #

Calls shutdown(2) with SHUT_RD


def close_write #

Calls shutdown(2) with SHUT_WR


def closed? : Bool #
Description copied from class IO

Returns true if this IO is closed.

IO defines returns false, but including types may override.


def connect(host : String, port : Int, connect_timeout = nil) : Nil #

Connects the socket to a remote host:port.

require "socket"

sock = Socket.tcp(Socket::Family::INET)
sock.connect "crystal-lang.org", 80

def connect(addr, timeout = nil) : Nil #

Connects the socket to a remote address. Raises if the connection failed.

require "socket"

sock = Socket.unix
sock.connect Socket::UNIXAddress.new("/tmp/service.sock")

def connect(addr, timeout = nil, &) #

Tries to connect to a remote address. Yields an IO::TimeoutError or an Socket::ConnectError error if the connection failed.


def family : Family #

def fcntl(cmd, arg = 0) #

def fd #

Returns the handle associated with this socket from the operating system.

  • on POSIX platforms, this is a file descriptor (Int32)
  • on Windows, this is a SOCKET handle (LibC::SOCKET)

def finalize #

Finalizes the socket resource.

This involves releasing the handle to the operating system, i.e. closing it. It does not implicitly call #flush, so data waiting in the buffer may be lost. By default write buffering is disabled, though (sync? == true). It's recommended to always close the socket explicitly via #close.

This method is a no-op if the file descriptor has already been closed.


def inspect(io : IO) : Nil #
Description copied from class Reference

Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.

class Person
  def initialize(@name : String, @age : Int32)
  end
end

Person.new("John", 32).inspect # => #<Person:0x10fd31f20 @name="John", @age=32>

def keepalive=(val : Bool) #

def keepalive? #

def linger #

def linger=(val : Int | Nil) #

WARNING The behavior of SO_LINGER is platform specific. Bad things may happen especially with nonblocking sockets. See Cross-Platform Testing of SO_LINGER by Nybek for more information.

  • nil: disable SO_LINGER
  • Int: enable SO_LINGER and set timeout to Int seconds
    • 0: abort on close (socket buffer is discarded and RST sent to peer). Depends on platform and whether shutdown() was called first.
    • >=1: abort after Int seconds on close. Linux and Cygwin may block on close.

def listen(backlog : Int = SOMAXCONN) : Nil #

Tells the previously bound socket to listen for incoming connections.


def listen(backlog : Int = SOMAXCONN, &) #

Tries to listen for connections on the previously bound socket. Yields an Socket::Error on failure.


def protocol : Protocol #

def read_timeout : Time::Span | Nil #

The time to wait when reading before raising an IO::TimeoutError.


def read_timeout=(read_timeout : Time::Span | Nil) #

The time to wait when reading before raising an IO::TimeoutError.


def read_timeout=(read_timeout : Number) : Number #

Sets the number of seconds to wait when reading before raising an IO::TimeoutError.

DEPRECATED Use #read_timeout=(Time::Span?) instead.


def receive(message : Bytes) : Tuple(Int32, Address) #

Receives a binary message from the previously bound address.

require "socket"

server = Socket.udp(Socket::Family::INET)
server.bind("localhost", 1234)

message = Bytes.new(32)
bytes_read, client_addr = server.receive(message)

def receive(max_message_size = 512) : Tuple(String, Address) #

Receives a text message from the previously bound address.

require "socket"

server = Socket.udp(Socket::Family::INET)
server.bind("localhost", 1234)

message, client_addr = server.receive

def recv_buffer_size : Int32 #

def recv_buffer_size=(val : Int32) #

def reuse_address=(val : Bool) #

def reuse_address? : Bool #

def reuse_port=(val : Bool) #

def reuse_port? : Bool #

def send(message, to addr : Address) : Int32 #

Sends a message to the specified remote address. Returns the number of bytes sent. Does not guarantee that the entire message is sent. That's only the case when the return value is equivalent to message.bytesize. #write ensures the entire message is sent but it requires an established connection.

require "socket"

server = Socket::IPAddress.new("10.0.3.1", 2022)
sock = Socket.udp(Socket::Family::INET)
sock.connect("example.com", 2000)
sock.send("text query", to: server)

def send(message) : Int32 #

Sends a message to a previously connected remote address. Returns the number of bytes sent. Does not guarantee that the entire message is sent. That's only the case when the return value is equivalent to message.bytesize. #write ensures the entire message is sent.

require "socket"

sock = Socket.udp(Socket::Family::INET)
sock.connect("example.com", 2000)
sock.send("text message")

sock = Socket.unix(Socket::Type::DGRAM)
sock.connect Socket::UNIXAddress.new("/tmp/service.sock")
sock.send(Bytes[0])

def send_buffer_size : Int32 #

def send_buffer_size=(val : Int32) #

def tty? #
Description copied from class IO

Returns true if this IO is associated with a terminal device (tty), false otherwise.

IO returns false, but including types may override.

STDIN.tty?          # => true
IO::Memory.new.tty? # => false

def type : Type #

def write_timeout : Time::Span | Nil #

Sets the time to wait when writing before raising an IO::TimeoutError.


def write_timeout=(write_timeout : Time::Span | Nil) #

Sets the time to wait when writing before raising an IO::TimeoutError.


def write_timeout=(write_timeout : Number) : Number #

Sets the number of seconds to wait when writing before raising an IO::TimeoutError.

DEPRECATED Use #write_timeout=(Time::Span?) instead.