Scott Hanselman's ComputerZen.com

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace ASPNETMVCUpgrader
{
    class Program
    {
        static void Main(string[] args)
        {
            if (!(args.Length == 1 )) {Console.WriteLine("Usage: ASPNETMVCUpgrader c:\\pathtomyprojectdir"); System.Environment.Exit(1); }
            //Remember there's TWO, count 'em, TWO web.configs. Madness!
            TidyUpFile(Path.Combine(args[0], "web.config"),Path.Combine(args[0], "Views\\web.config"));
        }
        private static void TidyUpFile(params string[] filename)
        {
          if (!filename.All(fn => File.Exists(fn)) )
            {
                // If it don't exist, don't bother creating strings.
                Console.WriteLine(String.Format("Can't find {0} or {1}. You sure it's there?", filename[0],filename[1]));
                System.Environment.Exit(1);
            }
            for(int i = 0; i < 2; i++)  {
          //Fix up the references!
            String MvcType = "System.Web.Mvc, Version=1.{0}.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35";
            String Routing = "<add name=\"UrlRoutingModule\" type=\"System.Web.Routing.UrlRoutingModule, System.Web.Routing, Version={0}.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35\"/>";
            string webconfigtext = File.ReadAllText(filename[i]);
            string newwebconfigtext = webconfigtext.Replace(string.Format(MvcType,"0"),String.Format(MvcType,"1"));   //(Old, New)
            newwebconfigtext = newwebconfigtext.Replace(string.Format(Routing, "3.5"), String.Format(Routing, "4.0"));    //(Old, New)
            //Keep up to two backups
            string backupWebConfig = Path.ChangeExtension(filename[i], ".mvc10backup");
            if (File.Exists(backupWebConfig))
            {
               var twoIsEnough = Path.ChangeExtension(filename[i], ".mvc10backup2");
               File.Delete(twoIsEnough);
               File.Copy(backupWebConfig, twoIsEnough);
               File.Delete(backupWebConfig);
            }
            File.Copy(filename[i], backupWebConfig);
            File.WriteAllText(filename[i], newwebconfigtext);
            //Toot!
            Console.WriteLine(String.Format("Updated MVC 1.0 references to MVC 1.1 for Dev10 Betas. \n Created a {0} backup. Toot.", filename));
            }
        }
    } 
}

        static void Main(string[] args)
        {
            if (args.Length != 1) { Console.WriteLine("Usage: ASPNETMVCUpgrader c:\\pathtomyprojectdir"); System.Environment.Exit(1); }
            //Remember there's TWO, count 'em, TWO web.configs. Madness!
            var messages = new[] { "web.config", @"Views\web.config" }
                    .Select(p => Path.Combine(args[0], p))
                    .Select(f => File.Exists(f) ? TidyUpFile(f) : String.Format("Can't find {0}. You sure it's there?", f));
            foreach (var m in messages) Console.WriteLine(m);
        }
        private static String MvcType = "System.Web.Mvc, Version={0}.0.0,";
        private static String Routing = "System.Web.Routing, Version={0}.0.0,";
        private static string TidyUpFile(string filename)
        {
            //Fix up the references!
            string newWebConfigText = File.ReadAllText(filename)
                .Replace(string.Format(MvcType, "1.0"), String.Format(MvcType, "1.1"))  //(Old, New)
                .Replace(string.Format(Routing, "3.5"), String.Format(Routing, "4.0")); //(Old, New)
            //Keep up to two backups
            string backupWebConfig = Path.ChangeExtension(filename, ".mvc10backup");
            if (File.Exists(backupWebConfig))
            {
                var twoIsEnough = Path.ChangeExtension(filename, ".mvc10backup2");
                File.Delete(twoIsEnough);
                File.Move(backupWebConfig, twoIsEnough);
            }
            File.Move(filename, backupWebConfig);
            File.WriteAllText(filename, newWebConfigText);
            //Toot!
            return String.Format("Updated MVC 1.0 references to MVC 1.1 for Dev10 Betas. \n Created a {0} backup. Toot.", filename);
        }

            var backupPaths = Enumerable.Repeat<int?>(null, 1)
                .Concat(Enumerable.Range(2, int.MaxValue - 2).Select(i => (int?)i))
                .Select(i => Path.ChangeExtension(filename, ".mvc10backup" + i));
            string toCopy = filename;
            foreach (var f in backupPaths.TakeWhile(_ => toCopy != null))
            {
                string temp = null;
                if (File.Exists(f))
                    File.Move(f, temp = f + "TEMP");
                File.Move(toCopy, f);
                toCopy = temp;
            }
            File.WriteAllText(filename, newWebConfigText);

static void Main(string[] args)
{
	if (args.Length == 0) Console.WriteLine("Usage: ASPNETMVCUpgrader pathToProject1 [pathToProject2] [pathToProject3]");

	Regex regex1 = new Regex(@"(?<1>System.Web.Mvc, Version=)1.0(?<2>.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35)", RegexOptions.Compiled);
	Regex regex2 = new Regex(@"(?<1><add name=""UrlRoutingModule"" type=""System.Web.Routing.UrlRoutingModule, System.Web.Routing, Version=)3.5(?<2>.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"" />)", RegexOptions.Compiled);

	foreach (var file in args
		.Select(p => new { Both = new[] { Path.Combine(p, "web.config"), Path.Combine(p, @"Views\web.config") } })
		.SelectMany(p => p.Both)
		.Select(p => new { Path = p, Content = File.ReadAllText(p) }))
	{
		try
		{
			File.Move(file.Path, Enumerable.Range(0, 100).Select(p => string.Format("{0}.backup_{1:00}", file.Path, p)).First(p => !File.Exists(p)));
			File.WriteAllText(file.Path, regex1.Replace(regex2.Replace(file.Content, "${1}4.0${2}"), "${1}1.1${2}"));
			Console.WriteLine("Done converting: {0}", file.Path);
		}
		catch (Exception ex) { Console.WriteLine("Error with: {0}" + Environment.NewLine + "Exception: {1}", file.Path, ex.Message); }
	}
}