Mirror of forum.nim-lang.org

14027 :: Doing unix-domain sockets in Nim

• yohannd1 (orginal) [2026-07-04T19:28:24+02:00] view original

  Hello! I've been trying to figure out how to do unix domain sockets in Nim, but I'm having issues. So far, what I have is:

  
  import std/[net, files, paths, strutils]
  
  let socketPath = "/tmp/something.sock"
  Path(socketPath).removeFile()
  
  let sck = newSocket(AF_UNIX, SOCK_STREAM, cast[Protocol](0))
  sck.bindUnix(socketPath)
  sck.listen()
  
  var client: Socket
  var address = ""
  while true:
    sck.acceptAddr(client, address)
    echo "Client connected from: ", address
    
    while true:
      var line: string
      sck.readLine(line)
      line = line.strip()
      
      if line == "quit":
        client.close()
        break
  Run

  First of all, I'm not sure if I'm specifying the protocol the best way possible - it doesn't seem like it has a 0-valued variant, so I had to use a cast. And second - the readLine call is erroring out, with an "Invalid argument" OSError. Not sure what is happening there.

  
  /usr/lib/nim/lib/pure/net.nim(1606) readLine
  /usr/lib/nim/lib/pure/net.nim(1007) socketError
  /usr/lib/nim/lib/std/oserrors.nim(92) raiseOSError
  Error: unhandled exception: Invalid argument [OSError]
  Run

---

• cblake (orginal) [2026-07-04T20:16:39+02:00] view original

  This uses SOCK_DGRAM not SOCK_STREAM, but has been working like a champ for me for over 6.5 years now: https://github.com/c-blake/kslog (kslog_open.nim does the bind part and then exec's the actual IO do-er).

---