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Class: TCPServer

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::TCPSocket, ::IPSocket, ::BasicSocket, ::IO
Instance Chain:
self, ::TCPSocket, ::IPSocket, ::BasicSocket, ::IO
Inherits: TCPSocket
Defined in: ext/socket/tcpserver.c,
ext/socket/socket.c,
ext/socket/lib/socket.rb

Overview

TCPServer represents a TCP/IP server socket.

A simple TCP server may look like:

require 'socket'

server = TCPServer.new 2000 # Server bind to port 2000
loop do
  client = server.accept    # Wait for a client to connect
  client.puts "Hello !"
  client.puts "Time is #{Time.now}"
  client.close
end

A more usable server (serving multiple clients):

require 'socket'

server = TCPServer.new 2000
loop do
  Thread.start(server.accept) do |client|
    client.puts "Hello !"
    client.puts "Time is #{Time.now}"
    client.close
  end
end

Class Attribute Summary

::BasicSocket - Inherited

.do_not_reverse_lookup

Gets the global do_not_reverse_lookup flag.
.do_not_reverse_lookup=

Sets the global do_not_reverse_lookup flag.

Class Method Summary

::TCPSocket - Inherited

.gethostbyname

Use Addrinfo.getaddrinfo instead.
.new

Opens a TCP connection to remote_host on remote_port.

::IPSocket - Inherited

.getaddress

Lookups the IP address of host.

::BasicSocket - Inherited

.for_fd

Returns a socket object which contains the file descriptor, fd.

Instance Attribute Summary

::BasicSocket - Inherited

#do_not_reverse_lookup

Gets the do_not_reverse_lookup flag of basicsocket.
#do_not_reverse_lookup=

Sets the do_not_reverse_lookup flag of basicsocket.

Instance Method Summary

::IPSocket - Inherited

#addr

Returns the local address as an array which contains address_family, port, hostname and numeric_address.
#inspect

Return a string describing this ::IPSocket object.
#peeraddr

Returns the remote address as an array which contains address_family, port, hostname and numeric_address.
#recvfrom

Receives a message and return the message as a string and an address which the message come from.

::BasicSocket - Inherited

#close_read

Disallows further read using shutdown system call.
#close_write

Disallows further write using shutdown system call.
#connect_address

Returns an address of the socket suitable for connect in the local machine.
#getpeereid

Returns the user and group on the peer of the UNIX socket.
#getpeername

Returns the remote address of the socket as a sockaddr string.
#getsockname

Returns the local address of the socket as a sockaddr string.
#getsockopt

Gets a socket option.
#local_address

Returns an ::Addrinfo object for local address obtained by getsockname.
#recv

Receives a message.
#recv_nonblock

Receives up to maxlen bytes from socket using recvfrom(2) after O_NONBLOCK is set for the underlying file descriptor.
#recvmsg

recvmsg receives a message using recvmsg(2) system call in blocking manner.
#recvmsg_nonblock

recvmsg receives a message using recvmsg(2) system call in non-blocking manner.
#remote_address

Returns an ::Addrinfo object for remote address obtained by getpeername.
#send

send mesg via basicsocket.
#sendmsg

sendmsg sends a message using sendmsg(2) system call in blocking manner.
#sendmsg_nonblock

sendmsg_nonblock sends a message using sendmsg(2) system call in non-blocking manner.
#setsockopt

Sets a socket option.
#shutdown

Calls shutdown(2) system call.
#__recvmsg, #__recvmsg_nonblock, #__sendmsg, #__sendmsg_nonblock, #read_nonblock, #write_nonblock, #__read_nonblock, #__recv_nonblock, #__write_nonblock

Constructor Details

.new([hostname,] port) ⇒ TCPServer

Creates a new server socket bound to port.

If hostname is given, the socket is bound to it.

serv = TCPServer.new("127.0.0.1", 28561)
s = serv.accept
s.puts Time.now
s.close

Internally, new calls getaddrinfo() function to obtain addresses. If getaddrinfo() returns multiple addresses, new tries to create a server socket for each address and returns first one that is successful.

[ GitHub ] 

  


# File 'ext/socket/tcpserver.c', line 33



static VALUE
tcp_svr_init(int argc, VALUE *argv, VALUE sock)
{
    VALUE hostname, port;

    rb_scan_args(argc, argv, "011", &hostname, &port);
    return rsock_init_inetsock(sock, hostname, port, Qnil, Qnil, INET_SERVER);
}


  







Instance Method Details



  

    #__accept_nonblock(ex)   (private)
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'ext/socket/tcpserver.c', line 68



static VALUE
tcp_accept_nonblock(VALUE sock, VALUE ex)
{
    rb_io_t *fptr;
    union_sockaddr from;
    socklen_t len = (socklen_t)sizeof(from);

    GetOpenFile(sock, fptr);
    return rsock_s_accept_nonblock(rb_cTCPSocket, ex, fptr, &from.addr, &len);
}


  








  

    #accept  ⇒ tcpsocket   



  

    

Accepts an incoming connection. It returns a new ::TCPSocket object.



TCPServer.open("127.0.0.1", 14641) {|serv|
  s = serv.accept
  s.puts Time.now
  s.close
}


  



  [ GitHub ]


  

  


# File 'ext/socket/tcpserver.c', line 55



static VALUE
tcp_accept(VALUE sock)
{
    rb_io_t *fptr;
    union_sockaddr from;
    socklen_t fromlen;

    GetOpenFile(sock, fptr);
    fromlen = (socklen_t)sizeof(from);
    return rsock_s_accept(rb_cTCPSocket, fptr->fd, &from.addr, &fromlen);
}


  








  

    #accept_nonblock([options])  ⇒ tcpsocket   



  

    

Accepts an incoming connection using accept(2) after O_NONBLOCK is set for the underlying file descriptor. It returns an accepted ::TCPSocket for the incoming connection.



Example



require 'socket'
serv = TCPServer.new(2202)
begin # emulate blocking accept
  sock = serv.accept_nonblock
rescue IO::WaitReadable, Errno::EINTR
  IO.select([serv])
  retry
end
# sock is an accepted socket.



Refer to Socket#accept for the exceptions that may be thrown if the call to accept_nonblock fails.



accept_nonblock may raise any error corresponding to accept(2) failure, including Errno::EWOULDBLOCK.



If the exception is Errno::EWOULDBLOCK, Errno::EAGAIN, Errno::ECONNABORTED, Errno::EPROTO, it is extended by IO::WaitReadable. So IO::WaitReadable can be used to rescue the exceptions for retrying accept_nonblock.



By specifying a keyword argument exception to false, you can indicate that accept_nonblock should not raise an IO::WaitReadable exception, but return the symbol :wait_readable instead.



See



  



  [ GitHub ]


  

  


# File 'ext/socket/lib/socket.rb', line 1313



def accept_nonblock(exception: true)
  __accept_nonblock(exception)
end


  








  

    #listen(int)  ⇒ 0   



  

    

Alias for Socket#listen.


  









  

    #sysaccept  ⇒ file_descriptor   



  

    

Returns a file descriptor of a accepted connection.



TCPServer.open("127.0.0.1", 28561) {|serv|
  fd = serv.sysaccept
  s = IO.for_fd(fd)
  s.puts Time.now
  s.close
}


  



  [ GitHub ]


  

  


# File 'ext/socket/tcpserver.c', line 93



static VALUE
tcp_sysaccept(VALUE sock)
{
    rb_io_t *fptr;
    union_sockaddr from;
    socklen_t fromlen;

    GetOpenFile(sock, fptr);
    fromlen = (socklen_t)sizeof(from);
    return rsock_s_accept(0, fptr->fd, &from.addr, &fromlen);
}