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socketsunixgofile-descriptor

Using os.OpenFile() instead of net.Listen()

I've dived into the call stack of both os.OpenFile and net.Listen to see if I can make a UNIX domain socket using os.OpenFile. Below is my attempt. But, after tracing both call stacks (os.OpenFile's and net.Listen's) I'm still confused. The below code doesn't read from the file, apparently, and stores the data to the filesystem.

  1. How can I implement a UNIX domain socket using os.OpenFile?
  2. What is the purpose of os.ModeSocket if it's not to be used with os.OpenFile to create a UNIX socket?
package main

import (
    "fmt"
    "log"
    "os"
)

func main() {
    sock, err := os.OpenFile("f.sock", os.O_RDWR|os.O_CREATE, os.ModeSocket|os.ModePerm)
    defer sock.Close()
    if err != nil {
        log.Panic(err)
    }
    n, err := sock.WriteString("hello\n")
    if err != nil {
        fmt.Println(err)
    } else {
        fmt.Println(n)
    }
    b := make([]byte, 10)
    n, err = sock.Read(b)
    fmt.Println(n)
    if err != nil {
        fmt.Println("error reading: ", err)
    }
    fmt.Println(b)
}
Solution

    1. No. OpenFile is a generalized api for opening file, use net.Listen("unixpacket", "f.sock") or net.Dial("unixpacket", "f.sock") if you wanna work with unix socket

    2. os.ModeSocket is just a *nix registered flag for socket fd, use when you want to filter fd types