class Socket

Included Modules

Direct Known Subclasses

Defined in:

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

Constructors

Class Method Summary

Instance Method Summary

Instance methods inherited from module IO::Syscall

read_syscall_helper(slice : Bytes, errno_msg : String, &block) : Int32 read_syscall_helper, read_timeout : Time::Span? read_timeout, read_timeout=(read_timeout : Number) : Number
read_timeout=(timeout : Time::Span?) : Time::Span? read_timeout=, write_syscall_helper(slice : Bytes, errno_msg : String, &block) : Nil write_syscall_helper, write_timeout : Time::Span? write_timeout, write_timeout=(write_timeout : Number) : Number
write_timeout=(timeout : Time::Span?) : Time::Span? write_timeout=

Instance methods inherited from module IO::Buffered

close : Nil close, flush flush, flush_on_newline=(flush_on_newline) flush_on_newline=, flush_on_newline? flush_on_newline?, peek : Bytes? peek, read(slice : Bytes) read, read_buffering=(read_buffering) read_buffering=, read_buffering? read_buffering?, rewind rewind, sync=(sync) sync=, sync? 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) write

Instance methods inherited from class IO

<<(obj) : self <<, close close, closed? closed?, each_byte(&block) : Nil
each_byte each_byte, each_char(&block) : Nil
each_char each_char, each_line(*args, **options, &block) : Nil
each_line(*args, **options) each_line, encoding : String encoding, flush flush, gets(delimiter : Char, limit : Int, chomp = false) : String?
gets(delimiter : Char, chomp = false) : String?
gets(chomp = true) : String?
gets(limit : Int, chomp = false) : String?
gets(delimiter : String, chomp = false) : String? gets, gets_to_end : String gets_to_end, peek : Bytes? peek, pos pos, pos=(value) pos=, print(*objects : UNDERSCORE) : Nil
print(obj) : Nil print, printf(format_string, *args) : Nil
printf(format_string, args : Array | Tuple) : Nil printf, puts(*objects : UNDERSCORE) : Nil
puts : Nil
puts(obj) : Nil
puts(string : String) : Nil puts, read(slice : Bytes) read, read_at(offset, bytesize, &block) read_at, read_byte : UInt8? read_byte, read_bytes(type, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) read_bytes, read_char : Char? read_char, read_fully(slice : Bytes) read_fully, read_fully?(slice : Bytes) 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 read_utf8_byte, rewind rewind, seek(offset, whence : Seek = Seek::Set) seek, set_encoding(encoding : String, invalid : Symbol? = 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) write_byte, write_bytes(object, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) write_bytes, write_utf8(slice : Bytes) write_utf8

Class methods inherited from class IO

copy(src, dst, limit : Int)
copy(src, dst) copy, pipe(read_blocking = false, write_blocking = false) : Tuple(IO::FileDescriptor, IO::FileDescriptor)
pipe(read_blocking = false, write_blocking = false, &block) pipe

Instance methods inherited from class Reference

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

Constructor methods inherited from class Reference

new new

Instance methods inherited from class Object

!=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other) ===, =~(other) =~, class class, dup dup, hash(hasher)
hash hash, inspect(io : IO)
inspect inspect, itself itself, not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, tap(&block) tap, to_json(io : IO)
to_json to_json, to_pretty_json(indent : String = " ")
to_pretty_json(io : IO, indent : String = " ") to_pretty_json, to_s
to_s(io : IO) to_s, to_yaml(io : IO)
to_yaml to_yaml, try(&block) try, unsafe_as(type : T.class) forall T unsafe_as

Constructor methods inherited from class Object

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

Constructor Detail

def self.new(fd : Int32, family, type, protocol = Protocol::IP, blocking = false) #

Creates a Socket from an existing socket file descriptor.


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

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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.


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

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


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

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


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Instance Method Detail

def accept #

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.now
socket.close

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def accept? #

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.now
  socket.close
end

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def bind(addr, &block) #

Tries to bind the socket to a local address. Yields an Errno if the binding failed.


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

Binds the socket to a local address.

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.

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

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def bind(addr) #

Binds the socket to a local address.

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? #

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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 #

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

Tries to connect to a remote address. Yields an IO::Timeout or an Errno error if the connection failed.


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

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

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

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

Connects the socket to a remote host:port.

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

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def family : Family #

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def fcntl(cmd, arg = 0) #

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def fd : Int32 #

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def finalize #

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def getsockopt(optname, optval, level = LibC::SOL_SOCKET) #

Returns the modified optval.


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def inspect(io) #

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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?) #

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) #

Tells the previously bound socket to listen for incoming connections.


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

Tries to listen for connections on the previously bound socket. Yields an Errno on failure.


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def protocol : Protocol #

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

Receives a text message from the previously bound address.

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

message, client_addr = server.receive

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

Receives a binary message from the previously bound address.

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 recv_buffer_size #

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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? #

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def reuse_port=(val : Bool) #

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def reuse_port? #

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def send(message, to addr : Address) #

Sends a message to the specified remote address.

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) #

Sends a message to a previously connected remote address.

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 #

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def send_buffer_size=(val : Int32) #

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def setsockopt(optname, optval, level = LibC::SOL_SOCKET) #

NOTE optval is restricted to Int32 until sizeof works on variables.


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def tty? #

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def type : Type #

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