Unix domain socket & tcp socket

The following codebase sets up a server using a Unix domain socket.

It creates a temporary file to serve as the socket address and establishes a listener on this socket with the net.Listen function. The server runs a goroutine to accept incoming connections and reads data from them. Additionally, the server is equipped with a signal handling mechanism to allow for graceful shutdown in response to interrupt signals.

package main

import (
    "fmt"
    "io/ioutil"
    "net"
    "os"
    "os/signal"
    "syscall"
)

func main() {
    // Creating a temporary file to use as the socket address.
    socketFile, err := ioutil.TempFile("", "socket")
    if err != nil {
        panic(err)
    }
    defer os.Remove(socketFile.Name()) // Ensure the socket file is removed on exit

    // Creating a listener on the Unix domain socket.
    listener, err := net.Listen("unix", socketFile.Name())
    if err != nil {
        panic(err)
    }
    defer listener.Close() // Ensure the listener is closed on exit

    // Setting up a channel to handle interrupt signals for graceful shutdown
    signals := make(chan os.Signal, 1)
    signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)

    // Starting an anonymous goroutine to accept connections on the listener.
    go func() {
        for {
            conn, err := listener.Accept()
            if err != nil {
                fmt.Println("Accept error:", err)
                break
            }

            // Reading data from the connection and printing it to the console.
            buf := make([]byte, 1024)
            n, err := conn.Read(buf)
            if err != nil {
                fmt.Println("Read error:", err)
                conn.Close()
                continue
            }
            fmt.Println(string(buf[:n]))

            // Closing the connection
            conn.Close()
        }
    }()

    // Wait for an interrupt signal
    <-signals
    fmt.Println("Server shutting down...")
}

A socket is an endpoint for sending and receiving data acros a computer network. It provides a way for processes to communicate with each other using a standard interface, regardless of the underlying network protocol.

A buffer, on the other hand, is a region of memory used to temporarily store data while it is being transferred between 2 locations. for instance, when sending data over a socket , the data may be first written to a buffer before being transmitted over the network.