using System;
using System.Runtime.InteropServices;

namespace PInvokeTest
{
    class Program
    {
        [UnmanagedFunctionPointer(CallingConvention.Cdecl, CharSet = CharSet.Ansi, SetLastError = false)]
        public delegate int printf_int(string format, int arg0);

        static void Main(string[] args)
        {
            var lib = NativeLibrary.Load("msvcrt.dll");
            var ptr = NativeLibrary.GetExport(lib, "printf");
            var func = Marshal.GetDelegateForFunctionPointer<printf_int>(ptr);
            var len = func.Invoke("Hello, World! %d\n", 123);
            Console.WriteLine($"printf returns {len}");
            NativeLibrary.Free(lib);
            Console.WriteLine("Hello World!");
        }
    }
}