DotDevTools/StdioSniffer/Program.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Linq;

namespace StdioSniffer
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            var cmd = Environment.GetCommandLineArgs();

            var path = Path.GetDirectoryName(cmd[0]);
            var file = Path.GetFileNameWithoutExtension(cmd[0]);
            var ext = Path.GetExtension(cmd[0]);

            var target = Path.Combine(path, $"{file}-real{ext}");
            var targetArgs = string.Join(" ", cmd.Skip(1));

            var logPath = Path.Combine(path, $"{file}{ext}.stdio-sniff.{DateTime.Now:yyyyMMdd-HHmmss-fff}.log");
            using var fs = File.CreateText(logPath);
            fs.AutoFlush = true;

            fs.WriteLine($"CMDLINE:{targetArgs}");

            var process = new Process
            {
                StartInfo =
                {
                    FileName = target,
                    Arguments = targetArgs,
                    UseShellExecute = false,
                    CreateNoWindow = true,
                    RedirectStandardError = true,
                    RedirectStandardInput = true,
                    RedirectStandardOutput = true
                }
            };

            process.OutputDataReceived += (sender, eventArgs) =>
            {
                var line = eventArgs.Data;
                fs.WriteLine($"STDOUT:{line}");
                Console.WriteLine(line);
                Console.Out.Flush();
            };

            process.ErrorDataReceived += (sender, eventArgs) =>
            {
                var line = eventArgs.Data;
                fs.WriteLine($"STDERR:{line}");
                Console.Error.WriteLine(line);
                Console.Error.Flush();
            };

            process.Start();

            process.BeginErrorReadLine();
            process.BeginOutputReadLine();

            while (false == process.HasExited)
            {
                var line = Console.ReadLine();
                fs.WriteLine($"STDIN:{line}");
                process.StandardInput.WriteLine(line);
                process.StandardInput.Flush();
            }
        }
    }
}