How can you determine how a console application wa

Question

How can I tell whether the user launched my console application by double-clicking the EXE (or a shortcut), or whether they already had a command line window open and executed my console app within that session?

Answer 1

You can find out what the parent process is:

    Console.WriteLine(System.Diagnostics.Process.GetCurrentProcess()?.Parent()?.ProcessName);

Where Parent() is an extension method, e.g.:

public static class Extensions
{
    private static string FindIndexedProcessName(int pid)
    {
        var processName = Process.GetProcessById(pid).ProcessName;
        var processesByName = Process.GetProcessesByName(processName);
        string processIndexdName = null;

        for (var index = 0; index < processesByName.Length; index++)
        {
            processIndexdName = index == 0 ? processName : processName + "#" + index;
            var processId = new PerformanceCounter("Process", "ID Process", processIndexdName);
            if ((int)processId.NextValue() == pid)
            {
                return processIndexdName;
            }
        }

        return processIndexdName;
    }

    private static Process FindPidFromIndexedProcessName(string indexedProcessName)
    {
        var parentId = new PerformanceCounter("Process", "Creating Process ID", indexedProcessName);
        return Process.GetProcessById((int)parentId.NextValue());
    }

    public static Process Parent(this Process process)
    {
        return FindPidFromIndexedProcessName(FindIndexedProcessName(process.Id));
    }
}

Answer 2

You might be able to figure it out by P/Invoking to the Win32 GetStartupInfo() function.

[DllImport("kernel32", CharSet=CharSet.Auto)]
internal static extern void GetStartupInfo([In, Out] STARTUPINFO lpStartupInfo);

Answer 3

Stick this static field in your "Program" class to ensure it runs before any output:

static bool StartedFromGui = 
         !Console.IsOutputRedirected
      && !Console.IsInputRedirected
      && !Console.IsErrorRedirected
      && Environment.UserInteractive
      && Environment.CurrentDirectory == System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetEntryAssembly().Location)
      && Console.CursorTop == 0 && Console.CursorLeft == 0
      && Console.Title == Environment.GetCommandLineArgs()[0]
      && Environment.GetCommandLineArgs()[0] == System.Reflection.Assembly.GetEntryAssembly().Location;

This is a little bit overkill/paranoid, but picks up being started from Explorer while not responding to things like cls && app.exe (by checking for the full path) or even cls && "f:\ull\path\to\app.exe" (by looking at the title).

I got the idea from the win32 version of this question.