Class: UNIXServer
Relationships & Source Files | |
Super Chains via Extension / Inclusion / Inheritance | |
Class Chain:
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Instance Chain:
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Inherits: |
UNIXSocket
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Defined in: | ext/socket/unixserver.c, ext/socket/socket.c, ext/socket/lib/socket.rb |
Overview
UNIXServer
represents a UNIX domain stream server socket.
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
-
.new(path) ⇒ UNIXServer
constructor
Creates a new UNIX server socket bound to path.
::UNIXSocket - Inherited
.new | Creates a new UNIX client socket connected to path. |
.pair | Creates a pair of sockets connected to each other. |
.socketpair | Alias for UNIXSocket.pair. |
::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
-
#accept ⇒ unixsocket
Accepts an incoming connection.
-
#accept_nonblock([options]) ⇒ unixsocket
Accepts an incoming connection using accept(2) after O_NONBLOCK is set for the underlying file descriptor.
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#listen(int) ⇒ 0
Alias for TCPServer#listen.
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#sysaccept ⇒ file_descriptor
Accepts a new connection.
::UNIXSocket - Inherited
#addr | Returns the local address as an array which contains address_family and unix_path. |
#path | Returns the path of the local address of unixsocket. |
#peeraddr | Returns the remote address as an array which contains address_family and unix_path. |
#recv_io | Example. |
#recvfrom | Receives a message via unixsocket. |
#send_io | Sends io as file descriptor passing. |
::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 |
#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 |
Constructor Details
.new(path) ⇒ UNIXServer
Creates a new UNIX server socket bound to path.
serv = UNIXServer.new("/tmp/sock")
s = serv.accept
p s.read
Instance Method Details
#accept ⇒ unixsocket
Accepts an incoming connection. It returns a new ::UNIXSocket object.
UNIXServer.open("/tmp/sock") {|serv|
UNIXSocket.open("/tmp/sock") {|c|
s = serv.accept
s.puts "hi"
s.close
p c.read #=> "hi\n"
}
}
#accept_nonblock([options]) ⇒ unixsocket
Accepts an incoming connection using accept(2) after O_NONBLOCK is set for the underlying file descriptor. It returns an accepted ::UNIXSocket for the incoming connection.
Example
require 'socket'
serv = UNIXServer.new("/tmp/sock")
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
or Errno::EPROTO
, it is extended by IO::WaitReadable
. So IO::WaitReadable
can be used to rescue the exceptions for retrying accept_nonblock.
By specifying exception: false
, the options hash allows you to indicate that accept_nonblock should not raise an IO::WaitReadable
exception, but return the symbol :wait_readable
instead.
See
# File 'ext/socket/lib/socket.rb', line 1348
def accept_nonblock(exception: true) __accept_nonblock(exception) end
#listen(int) ⇒ 0
Alias for TCPServer#listen. Listens for connections, using the specified int
as the backlog. A call to listen only applies if the socket
is of type SOCK_STREAM or SOCK_SEQPACKET.
Parameter
-
backlog
- the maximum length of the queue for pending connections.
Example 1
require 'socket'
include Socket::Constants
socket = Socket.new( AF_INET, SOCK_STREAM, 0 )
sockaddr = Socket.pack_sockaddr_in( 2200, 'localhost' )
socket.bind( sockaddr )
socket.listen( 5 )
Example 2 (listening on an arbitrary port, unix-based systems only):
require 'socket'
include Socket::Constants
socket = Socket.new( AF_INET, SOCK_STREAM, 0 )
socket.listen( 1 )
Unix-based Exceptions
On unix based systems the above will work because a new sockaddr
struct is created on the address ADDR_ANY, for an arbitrary port number as handed off by the kernel. It will not work on Windows, because Windows requires that the socket
is bound by calling bind before it can listen.
If the backlog amount exceeds the implementation-dependent maximum queue length, the implementation's maximum queue length will be used.
On unix-based based systems the following system exceptions may be raised if the call to listen fails:
-
Errno::EBADF
- the socket argument is not a valid file descriptor -
Errno::EDESTADDRREQ
- the socket is not bound to a local address, and the protocol does not support listening on an unbound socket -
Errno::EINVAL
- the socket is already connected -
Errno::ENOTSOCK
- the socket argument does not refer to a socket -
Errno::EOPNOTSUPP
- the socket protocol does not support listen -
Errno::EACCES
- the calling process does not have appropriate privileges -
Errno::EINVAL
- the socket has been shut down -
Errno::ENOBUFS
- insufficient resources are available in the system to complete the call
Windows Exceptions
On Windows systems the following system exceptions may be raised if the call to listen fails:
-
Errno::ENETDOWN
- the network is down -
Errno::EADDRINUSE
- the socket's local address is already in use. This usually occurs during the execution of bind but could be delayed if the call to bind was to a partially wildcard address (involving ADDR_ANY) and if a specific address needs to be committed at the time of the call to listen -
Errno::EINPROGRESS
- a Windows Sockets 1.1 call is in progress or the service provider is still processing a callback function -
Errno::EINVAL
- thesocket
has not been bound with a call to bind. -
Errno::EISCONN
- thesocket
is already connected -
Errno::EMFILE
- no more socket descriptors are available -
Errno::ENOBUFS
- no buffer space is available -
Errno::ENOTSOC
-socket
is not a socket -
Errno::EOPNOTSUPP
- the referencedsocket
is not a type that supports the listen method
See
-
listen manual pages on unix-based systems
-
listen function in Microsoft's Winsock functions reference
#sysaccept ⇒ file_descriptor
Accepts a new connection. It returns the new file descriptor which is an integer.
UNIXServer.open("/tmp/sock") {|serv|
UNIXSocket.open("/tmp/sock") {|c|
fd = serv.sysaccept
s = IO.new(fd)
s.puts "hi"
s.close
p c.read #=> "hi\n"
}
}