class TCPServer
Overview
A Transmission Control Protocol (TCP/IP) server.
Usage example:
require "socket"
server = TCPServer.new("localhost", 1234)
loop do
  server.accept do |client|
    message = client.gets
    client << message # echo the message back
  end
end
Options:
- backlog to specify how many pending connections are allowed;
 - reuse_port to enable multiple processes to bind to the same port (
SO_REUSEPORT). 
Included Modules
Defined in:
socket/tcp_server.crConstructors
- 
        .new(host : String, port : Int, backlog = SOMAXCONN, dns_timeout = nil, reuse_port = false)
        
          
Binds a socket to the host and port combination.
 - 
        .new(family : Family = Family::INET)
        
          
Creates a new
TCPServer, waiting to be bound. - 
        .new(port : Int, backlog = SOMAXCONN, reuse_port = false)
        
          
Creates a new TCP server, listening on all local interfaces (
::). 
Class Method Summary
- 
        .open(port : Int, backlog = SOMAXCONN, reuse_port = false, &block)
        
          
Creates a new TCP server, listening on all interfaces, and yields it to the block.
 - 
        .open(host, port, backlog = SOMAXCONN, reuse_port = false, &block)
        
          
Creates a new TCP server and yields it to the block.
 
Instance Method Summary
- 
        #accept?
        
          
Accepts an incoming connection.
 
Instance methods inherited from module Socket::Server
  
  
    
      accept(&block)
    accept, 
    
  
    
      accept?(&block)
    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?
    tcp_nodelay?
    
  
    
  Constructor methods inherited from class TCPSocket
  
  
    
      new(fd : Int32, family : Family, type : Type, protocol : Protocol)new(family : Family, type : Type, protocol : Protocol)
new(host, port, dns_timeout = nil, connect_timeout = nil)
new(family : Family = Family::INET) new
Class methods inherited from class TCPSocket
  
  
    
      open(host, port, &block)
    open
    
  
  
    
  Instance methods inherited from class IPSocket
  
  
    
      local_address
    local_address, 
    
  
    
      remote_address
    remote_address
    
  
    
    
  
    
  Instance methods inherited from class Socket
  
  
    
      accept
    accept, 
    
  
    
      accept?
    accept?, 
    
  
    
      bind(host : String, port : Int)bind(port : Int)
bind(addr)
bind(addr, &block) bind, broadcast=(val : Bool) broadcast=, broadcast? broadcast?, close_read close_read, close_write close_write, connect(host : String, port : Int, connect_timeout = nil)
connect(addr, timeout = nil) : Nil
connect(addr, timeout = nil, &block) connect, family : Family family, getsockopt(optname, optval, level = LibC::SOL_SOCKET) getsockopt, inspect(io) inspect, keepalive=(val : Bool) keepalive=, keepalive? keepalive?, linger linger, linger=(val : Int?) linger=, listen(backlog = SOMAXCONN)
listen(backlog = SOMAXCONN, &block) listen, protocol : Protocol protocol, receive(max_message_size = 512) : Tuple(String, Address)
receive(message : Bytes) : Tuple(Int32, Address) receive, recv_buffer_size recv_buffer_size, recv_buffer_size=(val : Int32) recv_buffer_size=, reuse_address=(val : Bool) reuse_address=, reuse_address? reuse_address?, reuse_port=(val : Bool) reuse_port=, reuse_port? reuse_port?, send(message, to addr : Address)
send(message) send, send_buffer_size send_buffer_size, send_buffer_size=(val : Int32) send_buffer_size=, setsockopt(optname, optval, level = LibC::SOL_SOCKET) setsockopt, type : Type type
Constructor methods inherited from class Socket
  
  
    
      new(fd : Int32, family, type, protocol = Protocol::IP)new(family, type, protocol = Protocol::IP, blocking = false) new
Class methods inherited from class Socket
  
  
    
      ip?(string : String)
    ip?, 
    
  
    
      tcp(family : Family, blocking = false)
    tcp, 
    
  
    
      udp(family : Family, blocking = false)
    udp, 
    
  
    
      unix(type : Type = Type::STREAM, blocking = false)
    unix
    
  
  
    
  Instance methods inherited from class IO::FileDescriptor
  
  
    
      blocking
    blocking, 
    
  
    
      blocking=(value)
    blocking=, 
    
  
    
      close_on_exec=(arg : Bool)
    close_on_exec=, 
    
  
    
      close_on_exec?
    close_on_exec?, 
    
  
    
      closed? : Bool
    closed?, 
    
  
    
      cooked(&block)
    cooked, 
    
  
    
      cooked!
    cooked!, 
    
  
    
      fcntl(cmd, arg = 0)
    fcntl, 
    
  
    
      fd : Int32
    fd, 
    
  
    
      finalize
    finalize, 
    
  
    
      inspect(io)
    inspect, 
    
  
    
      noecho(&block)
    noecho, 
    
  
    
      noecho!
    noecho!, 
    
  
    
      pos
    pos, 
    
  
    
      pos=(value)
    pos=, 
    
  
    
      pretty_print(pp)
    pretty_print, 
    
  
    
      raw(&block)
    raw, 
    
  
    
      raw!
    raw!, 
    
  
    
      read_timeout=(read_timeout : Time::Span)read_timeout=(read_timeout : Nil)
read_timeout=(read_timeout : Number) read_timeout=, reopen(other : IO::FileDescriptor) reopen, seek(offset, whence : Seek = Seek::Set)
seek(offset, whence : Seek = Seek::Set, &block) seek, stat stat, tell tell, tty? tty?, write_timed_out : Bool write_timed_out, write_timed_out=(write_timed_out : Bool) write_timed_out=, write_timeout=(write_timeout : Number)
write_timeout=(write_timeout : Time::Span)
write_timeout=(write_timeout : Nil) write_timeout=
Constructor methods inherited from class IO::FileDescriptor
  
  
    
      new(fd : Int32, blocking = false, edge_triggerable = false)
    new
    
  
    
  Class methods inherited from class IO::FileDescriptor
  
  
    
      fcntl(fd, cmd, arg = 0)
    fcntl
    
  
  
    
  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, 
    
  
    
      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 module IO
  
  
    
      <<(obj) : self
    <<, 
    
  
    
      close
    close, 
    
  
    
      closed?
    closed?, 
    
  
    
      each_byteeach_byte(&block) : Nil 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(limit : Int, chomp = false) : String?
gets(delimiter : Char, chomp = false) : String?
gets(delimiter : String, chomp = false) : String?
gets(chomp = true) : String?
gets(delimiter : Char, limit : Int, chomp = false) : String? gets, gets_to_end : String gets_to_end, peek : Bytes? peek, print(*objects : _) : Nil
print(obj) : Nil print, printf(format_string, args : Array | Tuple) : Nil
printf(format_string, *args) : Nil printf, puts(*objects : _) : Nil
puts : Nil
puts(obj) : Nil
puts(string : String) : Nil puts, read(slice : Bytes) read, 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, set_encoding(encoding : String, invalid : Symbol? = nil) set_encoding, skip(bytes_count : Int) : Nil skip, skip_to_end : Nil skip_to_end, 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 module IO
  
  
    
      copy(src, dst, limit : Int)copy(src, dst) copy, pipe(read_blocking = false, write_blocking = false)
pipe(read_blocking = false, write_blocking = false, &block) pipe
Instance methods inherited from class Reference
  
  
    
      ==(other : self)==(other) ==, dup dup, hash 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 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) : selffrom_json(string_or_io) : self from_json, from_yaml(string_or_io) : self from_yaml
Constructor Detail
Binds a socket to the host and port combination.
Creates a new TCPServer, waiting to be bound.
Creates a new TCP server, listening on all local interfaces (::).
Class Method Detail
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.
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.
Instance Method Detail
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