C gets an instance of TCP and UDP port that the Windows process is listening to

1. Under Windows, the command CMD netstat can be used to obtain information about the port number of the current process listening. For example, netstat-ano can see IP, port, status and PID listening.
Then the process CMD can be executed to get the port number information of the listener. The code of C# is as follows:

// process id
            int pid = ProcInfo.ProcessID;
            
            // A linked list of the port Numbers used by the process 
            List<int> ports = new List<int>();
 
            Process pro = new Process();
            pro.StartInfo.FileName = "cmd.exe";
            pro.StartInfo.UseShellExecute = false;
            pro.StartInfo.RedirectStandardInput = true;
            pro.StartInfo.RedirectStandardOutput = true;
            pro.StartInfo.RedirectStandardError = true;
            pro.StartInfo.CreateNoWindow = true;
            pro.Start();
            pro.StandardInput.WriteLine("netstat -ano");
            pro.StandardInput.WriteLine("exit");
            Regex reg = new Regex("\\s+", RegexOptions.Compiled);
            string line = null;
            ports.Clear();
            while ((line = pro.StandardOutput.ReadLine()) != null)
            {
                line = line.Trim();
                if (line.StartsWith("TCP", StringComparison.OrdinalIgnoreCase))
                {
                    line = reg.Replace(line, ",");
                    string[] arr = line.Split(',');
                    if (arr[4] == pid.ToString())
                    {
                        string soc = arr[1];
                        int pos = soc.LastIndexOf(':');
                        int pot = int.Parse(soc.Substring(pos + 1));
                        ports.Add(pot);
                    }
                }
                else if (line.StartsWith("UDP", StringComparison.OrdinalIgnoreCase))
                {
                    line = reg.Replace(line, ",");
                    string[] arr = line.Split(',');
                    if (arr[3] == pid.ToString())
                    {
                        string soc = arr[1];
                        int pos = soc.LastIndexOf(':');
                        int pot = int.Parse(soc.Substring(pos + 1));
                        ports.Add(pot);
                    }
                }
            }
            pro.Close();