NoDuplicatedStart.cs

using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using System.IO;
using System.Text.RegularExpressions;

namespace NoDuplicatedStart
{
    class Program
    {
        static void Main(string[] args)
        {
            if (args.Length == 0)
            {
                Console.WriteLine("Process not specified...");
            }
            else
            {
                string ProcessFileName = args[0].ToLower();
                string ProcessName = Regex.Match(ProcessFileName, @"([^\.\\]+)\.?\w*$").Groups[1].Value;

                Console.WriteLine("Checking for duplication...");
                foreach (Process p in Process.GetProcesses())
                {
                    if (ProcessName == p.ProcessName)
                    {
                        Console.WriteLine("Already working...");
                        return;
                    }
                }

                StringBuilder arg_sb = new StringBuilder();
                for (int i = 1; i < args.Length; ++i)
                {
                    arg_sb.Append(args[i]);
                    arg_sb.Append(' ');
                }

                Console.WriteLine("Starting...");
                Process process = new Process();
                process.StartInfo = new ProcessStartInfo(args[0], arg_sb.ToString());
                process.Start();
                Console.WriteLine("Process started...");
            }
        }
    }
}