How can I prevent ConsoleApp exit automatically in linux?

Question

I need to receive data from Serial Port A, convert and send it to Serial Port B. Now I am trying to use Raspberry And Raspberry OS to achieve this.

Here is my ConsoleApp coded by .net 5:

using System;
using System.IO.Ports;
using System.Linq;
using System.Threading.Tasks;
 namespace ConsoleApp1
 {
     internal class Program
     {
         private static SerialPort SP1 = new SerialPort("/dev/ttyUSB0", 57600, Parity.None, 8, StopBits.One);
         private static SerialPort SP2 = new SerialPort("/dev/ttyUSB1", 115200, Parity.None, 8, StopBits.One);        
         static void Main(string[] args)
         {
             SP1.DataReceived += SP_DataReceived;
             try
             {
                 SP1.Open();
                 SP2.Open();
             }
             catch(Exception ex){ 
                 Console.WriteLine(ex.Message);
             }                 
             Console.WriteLine("Started");
             Console.ReadKey();
         }
    
      static List<byte> ByteList = new List<byte>();
     private static void SP_DataReceived(object sender, SerialDataReceivedEventArgs e)
     {
         byte[] buf = new byte[SP1.BytesToRead];
         Console.WriteLine("DATA RECEIVED!");
         SP1!.Read(buf, 0, buf.Length);
         foreach (Byte b in buf)
         {
             ByteList.Add(b);
         }
         int StartIndex = -1;
         int EndIndex = -1;
         for (int i = 0; i < ByteList.Count; i++)
         {
             if (ByteList[i] == 2)
             {
                 StartIndex = i;
             }
             else if (ByteList[i] == 13 && ByteList.Count-1 > i&&ByteList[i+1]==10)
             {
                 EndIndex = i + 1;
                 break;
             }
         }
         List<byte> NewByteList = new List<byte>();
         if (StartIndex != -1 && EndIndex != -1)
         {                
             for (int i = StartIndex+1; i <= EndIndex-2; i++)
             {
                 NewByteList.Add(ByteList[i]);
             }
         }
         ByteList.RemoveRange(StartIndex, EndIndex - StartIndex+1);
         var Result = Encoding.UTF8.GetString(NewByteList.ToArray()).Split(" ").Last().Replace(Environment.NewLine, "");            
         if (!string.IsNullOrEmpty(Result))
         {
             Console.WriteLine(Result);
             if (SP2.IsOpen)
             {
                 SP2.Write(Result+Environment.NewLine);
             }
             else {
                 Console.WriteLine("SP2 is not opened");
             }
         }
     }
     }
 }

The program runs well while input dotnet ConsoleApp1.dll

After I set it run at the device startup, I found raspberry os reports this by journalctl -f -u Console1App.service :

Nov 08 07:22:42 raspberrypi dotnet-example[1412]: System.InvalidOperationException: Cannot read keys when either application does not have a console or when console input has been redirected. Try Console.Read.
Nov 08 07:22:42 raspberrypi dotnet-example[1412]:    at System.ConsolePal.ReadKey(Boolean intercept)
Nov 08 07:22:42 raspberrypi dotnet-example[1412]:    at System.Console.ReadKey()
Nov 08 07:22:42 raspberrypi dotnet-example[1412]:    at ConsoleApp1.Program.Main(String[] args) in C:\Users\abc\Desktop\ConsoleApp1\ConsoleApp1\Program.cs:line 57

It seems because the startup of Linux has not any console. The console.read of my program is just to block it exit automatically. How can I solve it?

Answer 1

You can use HostedService to keep your console application running all the time. The Microsoft doc explains how. Please read the documentation

I did this in a library I was developing for another job. You can look at readme as an example.