Serial port class for Unity on Linux

SerialPort.cs

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Linq;

class SerialPort : IDisposable
{
    [DllImport("libc.so.6", EntryPoint="open")]
    private static extern int Open(string path, int mode);

    [DllImport("libc.so.6", EntryPoint="close")]
    private static extern int Close(int fd);
    
    [DllImport("libc.so.6", EntryPoint="ioctl")]
    private static extern int Ioctl(int fd, int request, int data);
    
    [DllImport("libc.so.6", EntryPoint="read")]
    private static extern int Read(int fd, byte[] data, int length);
    
    [DllImport("libc.so.6", EntryPoint="write")]
    private static extern int Write(int fd, byte[] data, int length);

    private const int OPEN_READ_WRITE = 2;

    public string Port {get; set;}

    public int BaudRate {get; set;}

    public bool IsOpen => this.fd != 0;
    
    private int fd;

    public SerialPort(string port, int baudRate)
    {
        this.Port = port;
        this.BaudRate = baudRate;
    }
    
    public void Open()
    {
        this.fd = Open(this.Port, OPEN_READ_WRITE);
    }

    public void Close()
    {
        if( this.fd != 0 )
        {
            Close(this.fd);
        }
    }

    public void Write(string message)
    {
        var decoded = System.Text.UTF8Encoding.UTF8.GetBytes(message);
        Write(this.fd, decoded, decoded.Length);
    }

    public string ReadLine()
    {
        var buffer = new List<byte>();
        var charBuffer = new byte[1];
        for(;;)
        {
            if( Read(this.fd, charBuffer, 1) > 0 ) {
                if( charBuffer[0] == 10 ) {
                    break;
                }
                else {
                    buffer.Add(charBuffer[0]);
                }
            }
        }

        return System.Text.UTF8Encoding.UTF8.GetString(buffer.ToArray());
    }

    public void Dispose()
    {
        this.Close();
    }
}