How do I find the current executable filename?

If you want the executable:

System.Reflection.Assembly.GetEntryAssembly().Location

If you want the assembly that's consuming your library (which could be the same assembly as above, if your code is called directly from a class within your executable):

System.Reflection.Assembly.GetCallingAssembly().Location

If you'd like just the filename and not the path, use:

Path.GetFileName(System.Reflection.Assembly.GetEntryAssembly().Location)

In addition to the answers above.

I wrote following test.exe as console application

static void Main(string[] args) {
  Console.WriteLine(
    System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName);
  Console.WriteLine(
    System.Reflection.Assembly.GetEntryAssembly().Location);
  Console.WriteLine(
    System.Reflection.Assembly.GetExecutingAssembly().Location);
  Console.WriteLine(
    System.Reflection.Assembly.GetCallingAssembly().Location);
}

Then I compiled the project and renamed its output to the test2.exe file. The output lines were correct and the same.

But, if I start it in the Visual Studio, the result is:

d:\test2.vhost.exe

d:\test2.exe

d:\test2.exe

C:\Windows\Microsoft.NET\Framework\v2.0.50727\mscorlib.dll

The ReSharper plug-in to the Visual Studio has underlined the

System.Diagnostics.Process.GetCurrentProcess().MainModule

as possible System.NullReferenceException. If you look into documentation of the MainModule you will find that this property can throw also NotSupportedException, PlatformNotSupportedException and InvalidOperationException.

The GetEntryAssembly method is also not 100% "safe". MSDN:

The GetEntryAssembly method can return null when a managed assembly has been loaded from an unmanaged application. For example, if an unmanaged application creates an instance of a COM component written in C#, a call to the GetEntryAssembly method from the C# component returns null, because the entry point for the process was unmanaged code rather than a managed assembly.

For my solutions, I prefer the Assembly.GetEntryAssembly().Location.

More interest is if need to solve the problem for the virtualization. For example, we have a project, where we use a Xenocode Postbuild to