Program.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Text;
using System.Linq;
using System.Reflection;
using System.Text.Json;
using System.Runtime.InteropServices;
using Microsoft.Win32;
using System.Security.Cryptography;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Threading.Tasks;
using System.Threading;
using Microsoft.CodeAnalysis.Emit;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp.Scripting;
using Microsoft.CodeAnalysis.Scripting;
using System.Text.RegularExpressions;
using Microsoft.CodeAnalysis.Scripting.Hosting;
using Microsoft.CodeAnalysis.CSharp;
using System.IO.Compression;
using System.Net.Http;
using System.Net.Http.Headers;
using Microsoft.CodeAnalysis.Host.Mef;
using Microsoft.CodeAnalysis.Text;
using Microsoft.CodeAnalysis.Completion;

namespace CSharpScriptRunner
{
 public sealed class ScriptGlobals
 {
 public string[] Args { get; }

 internal ScriptGlobals(string[] args) => Args = args;
 }

 static partial class Program
 {
 const string CmdAlias = "csx";
 static readonly string CachePath = Path.Combine(Path.GetTempPath(), nameof(CSharpScriptRunner));

 const string UpdateRequestUri = "https://api.github.com/repos/ArgusMagnus/CSharpScriptRunner/releases/latest";
 const string PowershellUpdateCommand =
 @"$dir=md ""$Env:Temp\{$(New-Guid)}""; $bkp=$ProgressPreference; $ProgressPreference='SilentlyContinue'; Write-Host 'Downloading...'; Invoke-WebRequest (Invoke-RestMethod -Uri '" + UpdateRequestUri +
 @"' | select -Expand assets | select-string -InputObject {$_.browser_download_url} -Pattern '-win\.zip$' | Select -Expand Line -First 1) -OutFile ""$dir\CSX.zip""; Write-Host 'Expanding archive...'; Expand-Archive -Path ""$dir\CSX.zip"" -DestinationPath ""$dir""; & ""$dir\x64\CSharpScriptRunner.exe"" 'install'; Remove-Item $dir -Recurse; $ProgressPreference=$bkp; Write-Host 'Done'";


 static class Verbs
 {
 public const string Version = "--version";
 public const string Install = "install";
 public const string Update = "update";
 public const string New = "new";
 public const string ClearCache = "clear-cache";
 public const string InitVSCode = "init-vscode";
 public const string ListRunning = "list-running";
 public const string Repl = "repl";
 }

 enum ErrorCodes
 {
 OK = 0,
 GenericError,
 ScriptReturnRangeConflict,
 UnrecognizedArgument,
 ScriptFileDoesNotExist,
 ScriptCompilationFailed,
 Reserved = 0xFF
 }

 [STAThread]
 // Must run on STA thread (for WinForms/WPF support)
 static int Main(string[] args)
 {
 // return CurrentThreadSynchronizationContext.Run(async () => (int)(await MainAsync(args)));
 return (int)MainAsync(args).Result;
 }

 static async Task<ErrorCodes> MainAsync(string[] args)
 {
 using var syncCtxScope = new SynchronizationContextScope();
 await syncCtxScope.InstallAndYield(new CurrentThreadSynchronizationContext());
 Debug.Assert(Thread.CurrentThread.GetApartmentState() == ApartmentState.STA);
 using var thisProcess = Process.GetCurrentProcess();
 var dir = Path.Combine(Path.GetDirectoryName(thisProcess.MainModule.FileName), "running");
 Directory.CreateDirectory(dir);

 using var file = new FileStream(Path.Combine(dir, thisProcess.Id.ToString()), FileMode.Create, FileAccess.Write, FileShare.Read, 512, FileOptions.DeleteOnClose | FileOptions.Asynchronous);
 using (var writer = new StreamWriter(file, null, -1, true))
 await writer.WriteAsync(Environment.CommandLine);

 Console.WriteLine($"{nameof(CSharpScriptRunner)}, {BuildInfo.ReleaseTag}");

 if (args == null || args.Length == 0)
 {
 PrintHelp();
 return ErrorCodes.OK;
 }

 try
 {
 switch (args[0].ToLowerInvariant())
 {
 default: return await RunScript(args);
 case Verbs.Version: break;
 case Verbs.Install: await Install(args.Length > 1 ? string.Equals(args[1], "inplace", StringComparison.OrdinalIgnoreCase) : false); break;
 case Verbs.Update: await Update(); break;
 case Verbs.New: CreateNew(args.Length > 1 ? args[1] : null); break;
 case Verbs.ClearCache: await ClearCache(); break;
 case Verbs.InitVSCode: InitVSCode(); break;
 case Verbs.ListRunning: await ListRunning(); break;
 case Verbs.Repl: DoRepl(); break;
 }
 }
 catch (Exception ex)
 {
 if (ex is AggregateException aggregateException)
 ex = aggregateException.InnerException;
 WriteLineError(ex.ToString(), ConsoleColor.Red);
 return ErrorCodes.GenericError;
 }
 return ErrorCodes.OK;
 }

 static void PrintHelp()
 {
 var exe = Path.GetFileNameWithoutExtension(Process.GetCurrentProcess().MainModule.FileName);
 Console.WriteLine($"Alias: {CmdAlias}, {exe}");
 Console.WriteLine($"{CmdAlias} [-r<RT>] ScriptFilePath [args]");
 Console.WriteLine($" Executes the specified script.");
 Console.WriteLine($" <RT>: Runtime, e.g. x86/x64");
 Console.WriteLine($"{CmdAlias} {Verbs.Install}");
 Console.WriteLine($" Installs {exe} for the current user.");
 Console.WriteLine($"{CmdAlias} {Verbs.Update}");
 Console.WriteLine($" Updates {exe} for the current user.");
 Console.WriteLine($"{CmdAlias} {Verbs.New} [template]");
 Console.WriteLine($" If a template name is provided, a new script file [template].csx is created.");
 Console.WriteLine($" If the template name is omitted, the available templates are listed.");
 Console.WriteLine($"{CmdAlias} {Verbs.InitVSCode}");
 Console.WriteLine($" Initializes VS Code debugging support (creates .vscode directory)");
 Console.WriteLine($"{CmdAlias} {Verbs.ClearCache}");
 Console.WriteLine($" Cleares the cache of previously compiled scripts.");
 Console.WriteLine($"{CmdAlias} {Verbs.ListRunning}");
 Console.WriteLine($" Lists the currently running script engine instances.");
 Console.WriteLine($"{CmdAlias} {Verbs.Repl}");
 Console.WriteLine($" Experimental: Enter interactive (REPL) mode.");
 Console.WriteLine($"Returned error codes:");
 foreach (var code in Enum.GetValues<ErrorCodes>().Where(x => x != ErrorCodes.Reserved))
 Console.WriteLine($" - {code,3:D} {code}");
 Console.WriteLine($" - Value returned by script.");
 Console.WriteLine($" Values {ErrorCodes.OK + 1:D} - {ErrorCodes.Reserved:D} are reserved by the engine.");
 Console.WriteLine($" If a script returns a value in the reserved range, {ErrorCodes.ScriptReturnRangeConflict} will be returned instead.");
 }

 static void WriteLine(string line, ConsoleColor color = (ConsoleColor)(-1))
 {
 if ((int)color > -1)
 Console.ForegroundColor = color;
 Console.WriteLine(line);
 Console.ResetColor();
 }

 static void WriteLineError(string line, ConsoleColor color = (ConsoleColor)(-1))
 {
 if ((int)color > -1)
 Console.ForegroundColor = color;
 Console.Error.WriteLine(line);
 Console.ResetColor();
 }
 }
}