Asio provides basic support for UNIX domain sockets (also known as local sockets). The simplest use involves creating a pair of connected sockets. The following code:

local::stream_protocol::socket socket1(my_io_context);
local::stream_protocol::socket socket2(my_io_context);
local::connect_pair(socket1, socket2);

will create a pair of stream-oriented sockets. To do the same for datagram-oriented sockets, use:

local::datagram_protocol::socket socket1(my_io_context);
local::datagram_protocol::socket socket2(my_io_context);
local::connect_pair(socket1, socket2);

A UNIX domain socket server may be created by binding an acceptor to an endpoint, in much the same way as one does for a TCP server:

::unlink("/tmp/foobar"); // Remove previous binding.
local::stream_protocol::endpoint ep("/tmp/foobar");
local::stream_protocol::acceptor acceptor(my_io_context, ep);
local::stream_protocol::socket socket(my_io_context);
acceptor.accept(socket);

A client that connects to this server might look like:

local::stream_protocol::endpoint ep("/tmp/foobar");
local::stream_protocol::socket socket(my_io_context);
socket.connect(ep);

Transmission of file descriptors or credentials across UNIX domain sockets is not directly supported within Asio, but may be achieved by accessing the socket's underlying descriptor using the native_handle() member function.

See Also

local::connect_pair, local::datagram_protocol, local::datagram_protocol::endpoint, local::datagram_protocol::socket, local::stream_protocol, local::stream_protocol::acceptor, local::stream_protocol::endpoint, local::stream_protocol::iostream, local::stream_protocol::socket, UNIX domain sockets examples.

Notes

UNIX domain sockets are only available at compile time if supported by the target operating system. A program may test for the macro ASIO_HAS_LOCAL_SOCKETS to determine whether they are supported.