Whoami

Code to translate user name to Windows SID

using System;
using System.DirectoryServices;
using System.Security.Principal;


class Program
{
  static void Main(string[] args)
  {
    foreach (string arg in args)
    {
      string path = String.Format("WinNT://KBCFP/{0}", arg);
      DirectoryEntry root = 
        new DirectoryEntry(path, null, null, 
        AuthenticationTypes.Secure);
      SecurityIdentifier si = 
        new SecurityIdentifier((byte[])
        root.Properties["objectSid"][0], 0);
      Console.WriteLine("{0}: {1}", arg, si.Value);
    }
  }
}