Unix domain sockets

Cross platform point-to-point inter-process communication with Unix=domain sockets, implemented via named pipes on Windows. These connection are always bidirectional, i.e. you can read from them and also write to them.

Usage

conn_create_unix_socket(filename = NULL, encoding = "")

conn_connect_unix_socket(filename, encoding = "")

conn_accept_unix_socket(con)

conn_unix_socket_state(con)

Arguments

filename

File name of the socket. On Windows it the name of the pipe within the \\?\pipe\ namespace, either the full name, or the part after that prefix. If NULL, then a random name is used, on Unix in the R temporary directory: base::tempdir().

encoding

Encoding to assume when reading from the socket.

con

Connection. An error is thrown if not a socket connection.

Value

A new socket connection.

Details

conn_create_unix_socket() creates a server socket. The new socket is listening at filename. See filename above.

conn_connect_unix_socket() creates a client socket and connects it to a server socket.

conn_accept_unix_socket() accepts a client connection at a server socket.

conn_unix_socket_state() returns the state of the socket. Currently it can return: "listening", "connected_server", "connected_client". It is possible that other states (e.g. for a closed socket) will be added in the future.

Notes

• poll() works on sockets, but only polls for data to read, and currently ignores the write-end of the socket.

• poll() also works for accepting client connections. It will return "connect"is a client connection is available for a server socket. After this you can call conn_accept_unix_socket() to accept the client connection.

See also

processx internals