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

Instance methods inherited from module IO::Evented

evented_close : Nil evented_close, evented_read(slice : Bytes, errno_msg : String, &) : Int32 evented_read, evented_reopen : Nil evented_reopen, evented_send(slice : Bytes, errno_msg : String, &) : Int32 evented_send, evented_write(slice : Bytes, errno_msg : String, &) : Nil evented_write

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) #

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

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


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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.


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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.


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Class Method Detail

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

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def self.ip?(string : String) #

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

DEPRECATED Use IPAddress.valid? instead


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

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


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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

[View source]
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

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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

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def bind(port : Int) #

Binds the socket on port to all local interfaces.

require "socket"

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

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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)

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def blocking #

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def blocking=(value) #

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def broadcast=(val : Bool) #

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def broadcast? : Bool #

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def close_on_exec=(arg : Bool) #

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def close_on_exec? #

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def close_read #

Calls shutdown(2) with SHUT_RD


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def close_write #

Calls shutdown(2) with SHUT_WR


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def closed? : Bool #
Description copied from class IO

Returns true if this IO is closed.

IO defines returns false, but including types may override.


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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

[View source]
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")

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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.


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def family : Family #

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def fcntl(cmd, arg = 0) #

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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)

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def finalize #

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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>

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def keepalive=(val : Bool) #

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def keepalive? #

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def linger #

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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.

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

Tells the previously bound socket to listen for incoming connections.


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

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


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def protocol : Protocol #

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def read_timeout : Time::Span | Nil #

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


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

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


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def read_timeout=(read_timeout : Number) : Number #

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


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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)

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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

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def recv_buffer_size : Int32 #

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def recv_buffer_size=(val : Int32) #

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def reuse_address=(val : Bool) #

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def reuse_address? : Bool #

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def reuse_port=(val : Bool) #

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def reuse_port? : Bool #

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

Sends a message to the specified remote address.

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)

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def send(message) : Int32 #

Sends a message to a previously connected remote address.

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])

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def send_buffer_size : Int32 #

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def send_buffer_size=(val : Int32) #

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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

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def type : Type #

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def write_timeout : Time::Span | Nil #

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


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

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


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def write_timeout=(write_timeout : Number) : Number #

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


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