class TCPServer

Overview

A Transmission Control Protocol (TCP/IP) server.

NOTE To use TCPServer, you must explicitly import it with require "socket"

Usage example:

require "socket"

def handle_client(client)
  message = client.gets
  client.puts message
end

server = TCPServer.new("localhost", 1234)
while client = server.accept?
  spawn handle_client(client)
end

Options:

Included Modules

Defined in:

socket/tcp_server.cr

Constructors

Class Method Summary

Instance Method Summary

Instance methods inherited from module Socket::Server

accept : IO
accept(&)
accept
, accept? : IO | Nil
accept?(&)
accept?

Instance methods inherited from class TCPSocket

tcp_keepalive_count tcp_keepalive_count, tcp_keepalive_count=(val : Int) tcp_keepalive_count=, tcp_keepalive_idle tcp_keepalive_idle, tcp_keepalive_idle=(val : Int) tcp_keepalive_idle=, tcp_keepalive_interval tcp_keepalive_interval, tcp_keepalive_interval=(val : Int) tcp_keepalive_interval=, tcp_nodelay=(val : Bool) tcp_nodelay=, tcp_nodelay? : Bool tcp_nodelay?

Constructor methods inherited from class TCPSocket

new(family : Family = Family::INET, blocking = false)
new(host, port, dns_timeout = nil, connect_timeout = nil, blocking = false)
new(*, fd : Handle, family : Family = Family::INET, blocking = false)
new

Class methods inherited from class TCPSocket

open(host, port, &) open

Instance methods inherited from class IPSocket

bind(addr) bind, close close, connect(addr, timeout = nil, &) connect, local_address : Socket::IPAddress local_address, remote_address : Socket::IPAddress remote_address

Instance methods inherited from class Socket

accept : Socket accept, accept? : Socket | Nil accept?, bind(host : String, port : Int) : Nil
bind(port : Int)
bind(addr : Socket::Address) : Nil
bind
, blocking blocking, blocking=(value) blocking=, broadcast=(val : Bool) broadcast=, broadcast? : Bool broadcast?, close_on_exec=(arg : Bool) close_on_exec=, close_on_exec? close_on_exec?, close_read close_read, close_write close_write, closed? : Bool closed?, connect(host : String, port : Int, connect_timeout = nil) : Nil
connect(addr, timeout = nil) : Nil
connect(addr, timeout = nil, &)
connect
, family : Family family, fcntl(cmd, arg = 0) fcntl, fd fd, finalize finalize, inspect(io : IO) : Nil inspect, keepalive=(val : Bool) keepalive=, keepalive? keepalive?, linger linger, linger=(val : Int | Nil) linger=, listen(backlog : Int = SOMAXCONN) : Nil
listen(backlog : Int = SOMAXCONN, &)
listen
, protocol : Protocol protocol, receive(message : Bytes) : Tuple(Int32, Address)
receive(max_message_size = 512) : Tuple(String, Address)
receive
, recv_buffer_size : Int32 recv_buffer_size, recv_buffer_size=(val : Int32) recv_buffer_size=, reuse_address=(val : Bool) reuse_address=, reuse_address? : Bool reuse_address?, reuse_port=(val : Bool) reuse_port=, reuse_port? : Bool reuse_port?, send(message, to addr : Address) : Int32
send(message) : Int32
send
, send_buffer_size : Int32 send_buffer_size, send_buffer_size=(val : Int32) send_buffer_size=, tty? tty?, type : Type type

Constructor methods inherited from class Socket

new(family : Family, type : Type, protocol : Protocol = Protocol::IP, blocking = false)
new(fd, family : Family, type : Type, protocol : Protocol = Protocol::IP, blocking = false)
new
, tcp(family : Family, blocking = false) : self tcp, unix(type : Type = Type::STREAM, blocking = false) : self unix

Class methods inherited from class Socket

fcntl(fd, cmd, arg = 0) fcntl, ip?(string : String) ip?, udp(family : Family, blocking = false) udp

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, read_timeout : Time::Span | Nil read_timeout, read_timeout=(read_timeout : Number) : Number
read_timeout=(timeout : Time::Span | Nil) : Time::Span | Nil
read_timeout=
, write_timeout : Time::Span | Nil write_timeout, write_timeout=(write_timeout : Number) : Number
write_timeout=(timeout : Time::Span | Nil) : Time::Span | Nil
write_timeout=

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

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

Constructor Detail

def self.new(host : String, port : Int, backlog : Int = SOMAXCONN, dns_timeout = nil, reuse_port : Bool = false) #

Binds a socket to the host and port combination.


[View source]
def self.new(family : Family = Family::INET) #

Creates a new TCPServer, waiting to be bound.


[View source]
def self.new(port : Int, backlog = SOMAXCONN, reuse_port = false) #

Creates a new TCP server, listening on all local interfaces (::).


[View source]
def self.new(*, fd : Handle, family : Family = Family::INET) #

Creates a TCPServer from an already configured raw file descriptor


[View source]

Class Method Detail

def self.open(port : Int, backlog = SOMAXCONN, reuse_port = false, &) #

Creates a new TCP server, listening on all interfaces, and yields it to the block. Eventually closes the server socket when the block returns.

Returns the value of the block.


[View source]
def self.open(host, port, backlog = SOMAXCONN, reuse_port = false, &) #

Creates a new TCP server and yields it to the block. Eventually closes the server socket when the block returns.

Returns the value of the block.


[View source]

Instance Method Detail

def accept? : TCPSocket | Nil #

Accepts an incoming connection.

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

require "socket"

server = TCPServer.new(2022)
loop do
  if socket = server.accept?
    # handle the client in a fiber
    spawn handle_connection(socket)
  else
    # another fiber closed the server
    break
  end
end

[View source]