How to set up a 'listening' Unix domain socket

[Robert Latest]

Hello,

I'm trying to set up a server that receives data on a Unix domain socket using
the code below.

import os from socketserver import UnixStreamServer, StreamRequestHandler

SOCKET = '/tmp/test.socket'

class Handler(StreamRequestHandler):

    def handle(self): data = selr.rfile.read() print(data)

if os.path.exists(SOCKET): os.unlink(SOCKET) with UnixStreamServer(SOCKET,
    Handler) as server: server.serve_forever()


However, when I try to send somthing to that socket, I get this error message:

$ echo "Hello" | socat - UNIX-SENDTO:/tmp/test.socket 2021/03/22 11:03:22
socat[2188] E sendto(5, 0x55a22f414990, 6, 0, AF=1 "/tmp/test.socket", 18):
Protocol wrong type for socket

I don't understand that error. Here's /tmp/test.socket:

$ stat /tmp/test.socket
  File: ‘/tmp/test.socket’
  Size: 0               Blocks: 0          IO Block: 4096   socket
Device: fd00h/64768d    Inode: 201443577   Links: 1
Access: (0775/srwxrwxr-x)  Uid: ( 1001/      dh)   Gid: ( 1001/      dh)
Context: unconfined_u:object_r:user_tmp_t:s0
Access: 2021-03-22 09:47:49.516298102 +0100
Modify: 2021-03-22 09:47:49.516298102 +0100
Change: 2021-03-22 09:47:49.516298102 +0100
 Birth: -

Sadly all examples I can find on the web are for TCP sockets, not Unix domain.

Any tips?
robert