Example of Extension Method & Call CMD No Window

 using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Diagnostics;

using System.Windows.Forms;

using System.Collections;

using System.Text.RegularExpressions;

namespace Infor.SyteLine.Search.SearchEngine

{

    /// <summary>

    /// Searcher to search the specified string in file(s).

    /// </summary>

    internal class FileSearcher : ISearchable

    {

        private static readonly string FindStrCommand = @"findstr /S /N ""{0}"" {1} \(-name \*.txt -o -name \*.vb -o -name \*.sql \)";

        private const string Cmd = "cmd.exe";

        private const string LineBreakMark = "\n";

        private const string ExitCommand = "exit";

        /// <summary>

        /// Searches the specified string in file(s).

        /// </summary>

        /// <param name="value"></param>

        public string Search(string value, string directory)

        {

            var process = new Process();

            process.StartInfo.FileName = Cmd;

            process.StartInfo.UseShellExecute = false;

            process.StartInfo.RedirectStandardInput = true;

            process.StartInfo.RedirectStandardOutput = true;

            process.StartInfo.RedirectStandardError = true;

            process.StartInfo.CreateNoWindow = true;

            process.Start();

            process.StandardInput.AutoFlush = true;

            string commandline = string.Format(FindStrCommand, value, directory);

            process.StandardInput.WriteLine(commandline);

            process.StandardInput.WriteLine(ExitCommand);

            string strRst = process.StandardOutput.ReadToEnd();

            process.WaitForExit();

            process.Close();

            CloseProcess(Cmd);

            // Remove additional head and foot.

            int contentStartPosition = strRst.IndexOfOccurence(LineBreakMark, 4);

            int lineNum = Regex.Matches(strRst, LineBreakMark).Count;

            int contentEndPosition = strRst.IndexOfOccurence(LineBreakMark, lineNum - 2);

            return strRst.Substring(contentStartPosition, contentEndPosition - contentStartPosition);

        }

        /// <summary>

        /// Closes the process of given name.

        /// </summary>

        /// <param name="processName">to close.</param>

        public void CloseProcess(string processName)

        {

            foreach (System.Diagnostics.Process process in System.Diagnostics.Process.GetProcesses())

            {

                string tempName = process.ToString();

                int begpos = tempName.IndexOf("(") + 1;

                int endpos = tempName.IndexOf(")");

                tempName = tempName.Substring(begpos, endpos - begpos);

 

                if (tempName == processName)

                {

                    if (!process.CloseMainWindow()) 

                    {

                        process.Kill(); 

                    }                        

                }

            }

        }

    }

    internal static class StringExtensionHelper

    {

        public static int IndexOfOccurence(this string stringToSearch, string match, int occurence)

        {

            int index = 0;

            for (int count = 1; count <= occurence && (index = stringToSearch.IndexOf(match, index + 1)) != -1; count++)

            {

                if (count == occurence)

                    return index;

            }

            return -1;

        }

    }

}