Running external process with stdin/out/err redirection

ProcessIO.cs

// Video: https://youtu.be/cdTu27j6dn8

using System.Diagnostics;
using System.Text;

// Verify there are exactly 2 arguments and get source and destination folders
if (args.Length != 2) {
    Console.WriteLine("Usage: mirror <source folder> <destination folder>");
    return;
}
var sourceFolder = args[0];
var destinationFolder = args[1];

// Create process start info to run ROBOCOPY
var psi = new ProcessStartInfo {
    FileName = "robocopy.exe",                  // Name of the executable
    UseShellExecute = false,                    // Cannot use shell execute when redirecting IO
    CreateNoWindow = true,                      // Don't create visible window
    RedirectStandardOutput = true,              // Redirect stdout to the process object
    RedirectStandardError = true,               // Redirect stderr to the process object
    RedirectStandardInput = true,               // Redirect stdin to the process object
    StandardOutputEncoding = Encoding.UTF8,     // Encoding for stdout
    StandardErrorEncoding = Encoding.UTF8,      // Encoding for stderr
    StandardInputEncoding = Encoding.UTF8,      // Encoding for stdin
};

// Add command line arguments - it's better than concatenating strings to Arguments property
psi.ArgumentList.Add(sourceFolder);             // Source folder
psi.ArgumentList.Add(destinationFolder);        // Destination folder
psi.ArgumentList.Add("/MIR");                   // Mirror the source folder
psi.ArgumentList.Add("/NP");                    // Don't show progress percentage

// Run ROBOCOPY
using var process = Process.Start(psi);
if (process == null) {
    Console.WriteLine("Error: Failed to start ROBOCOPY");
    return;
}

#region Option 1: Read all stdout data at once

Console.Write("Running ROBOCOPY... ");
var output = process.StandardOutput.ReadToEnd();
Console.WriteLine("OK");
Console.WriteLine(output);

#endregion

#region Option 2: Read stdout data line by line

//while (!process.StandardOutput.EndOfStream) {
//    var line = process.StandardOutput.ReadLine();
//    Console.WriteLine(line);
//}

#endregion

#region Option 3: Read stdout data asynchronously as received

//process.OutputDataReceived += (sender, e) => Console.WriteLine(e.Data);
//process.BeginOutputReadLine();
//process.WaitForExit();

#endregion

// Check exit code
Console.WriteLine($"Exit code: {process.ExitCode}");