How it works…

Once we run the program, the TCP server will start locally listening on port 8080.

Let’s understand what each line in the program means:

• package main: This defines the package name of the program.
• import ( "log" "net"): This is a preprocessor command that tells the Go compiler to include all files from the log and net package.
• const ( CONN_HOST = "localhost" CONN_PORT = "8080" CONN_TYPE = "tcp" ): We declare constants in a Go program using the const keyword. Here, we declare three constants—one is CONN_HOST with a value of localhost, another one is CONN_PORT with a value as 8080, and lastly CONN_TYPE with a value as tcp.

Next, we declared the main() method from where the program execution begins. As this method does a lot of things, let’s understand it line by line:

• listener, err := net.Listen(CONN_TYPE, CONN_HOST+":"+CONN_PORT): This creates a TCP server running on localhost at port 8080.
• if err != nil { log.Fatal("Error starting tcp server: ", err) }: Here, we check if there is any problem in starting the TCP server. If there is, then log the error and exit with a status code of 1.
• defer listener.Close(): This defer statement closes a TCP socket listener when the application closes.

Next, we accept the incoming request to the TCP server in a constant loop, and if there are any errors in accepting the request, then we log it and exit; otherwise, we simply print the connection object on the server console, as follows:

for 
{
  conn, err := listener.Accept()
  if err != nil 
  {
    log.Fatal("Error accepting: ", err.Error())
  }
  log.Println(conn)
}