LinefeedPurger - Detects all invalid LF files in C# (.cs) files from git top-level - .NETCore

Program.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;

namespace LinefeedPurger
{
	class Program
	{
		static void Main(string[] args)
		{
			string gitTopLevel = GitTopLevel();
			Console.WriteLine($"||\tAssuming top level: {gitTopLevel}");
			var csFiles = new List<string>();
			GetCsFiles(gitTopLevel, ref csFiles);
			Console.WriteLine($"||\tAssuming files: {csFiles}");
			foreach (string csFile in csFiles)
			{
				string fileName = csFile.Replace("/", "\\");
				string content = File.ReadAllText(fileName);
				content = Regex.Replace(content, "\r\n", "_");
				if (Regex.IsMatch(content, "\n", RegexOptions.Multiline))
				{
					Console.WriteLine($"EE\tMatches LF: {fileName}");
				}
				else
				{
					Console.WriteLine($"||\tMatches CRLF: {fileName}");
				}
			}
		}

		private static void GetCsFiles(string path, ref List<string> csFiles)
		{
			try
			{
				foreach (string d in Directory.GetDirectories(path))
				{
					foreach (string f in Directory.GetFiles(d))
					{
						if (Regex.IsMatch(f, "\\.cs$"))
						{
							csFiles.Add(f);
						}
					}
					GetCsFiles(d, ref csFiles);
				}
			}
			catch (Exception e)
			{
				Console.WriteLine(e.Message);
			}
		}

		private static string GitTopLevel()
		{
			return GitCommand("rev-parse --show-toplevel");
		}

		private static string GitCommand(string command)
		{
			var stderr = new StringBuilder();
			var stdout = new StringBuilder();
			try
			{
				ProcessStartInfo startInfo = new ProcessStartInfo();
				startInfo.FileName = "git";
				startInfo.Arguments = command;
				startInfo.RedirectStandardOutput = true;
				startInfo.RedirectStandardError = true;
				startInfo.UseShellExecute = false;
				startInfo.CreateNoWindow = true;

				using (Process process = Process.Start(startInfo))
				{
					

					while (!process.StandardOutput.EndOfStream)
					{
						string line = process.StandardOutput.ReadLine();
						stdout.AppendLine(line);
						Console.WriteLine(line);
					}

					while (!process.StandardError.EndOfStream)
					{
						string line = process.StandardError.ReadLine();
						stderr.AppendLine(line);
						Console.WriteLine(line);
					}

					process.WaitForExit();
				}
			}
			catch (Exception Ex)
			{
				Console.WriteLine(Ex.Message);
			}
			return stdout.ToString().Trim() + stderr.ToString().Trim();
		}
	}
}