How to Execute Command in C# ?

It is normal practice to open the command prompt and execute commands. The command when executed shows the result onto the screen. There are many commands that we execute daily such as dir, find etc. C# programmers have to code in diverse satiations. A situation may arise when you want to execute a (shell) command from the C# application. Don’t Worry!!! Here is the code to do so…

In the code given below we create a process i.e. a command process and then invoke the command that we want to execute. The result of the command is stored in a string variable, which can then be used for further references. The command execution can happen in two ways, synchronously and asynchronously.  In the asynchronous command execution we just invoke the command execution using a thread that runs independently.

using System;

using System.Threading;

 

namespace ExecuteCommand

{

    public class Program

    {

        static void Main(string[] args)

        {

            string command = String.Empty;

 

            // Write to the console.

            Console.Write("Enter the command you wish to execute: ");

 

            // Get the command you wish to execute.

            command = Console.ReadLine().Trim();

 

            // Execute the command synchronously.

            ExecuteCmd exe = new ExecuteCmd();

            exe.ExecuteCommandSync(command);

 

            // Execute the command asynchronously.

            exe.ExecuteCommandAsync(command);

 

            // Your' done !!!

            Console.WriteLine("\nDone !");

            Console.ReadLine();

        }

    }

 

    public class ExecuteCmd

    {

        #region ExecuteCommand Sync and Async

        /// <summary>

        /// Executes a shell command synchronously.

        /// </summary>

        /// <param name="command">string command</param>

        /// <returns>string, as output of the command.</returns>

        public void ExecuteCommandSync(object command)

        {

            try

            {

                // create the ProcessStartInfo using "cmd" as the program to be run, and "/c " as the parameters.

                // Incidentally, /c tells cmd that we want it to execute the command that follows, and then exit.

                System.Diagnostics.ProcessStartInfo procStartInfo = new System.Diagnostics.ProcessStartInfo("cmd", "/c " + command);

                // The following commands are needed to redirect the standard output.

                //This means that it will be redirected to the Process.StandardOutput StreamReader.

                procStartInfo.RedirectStandardOutput = true;

                procStartInfo.UseShellExecute = false;

                // Do not create the black window.

                procStartInfo.CreateNoWindow = true;

                // Now we create a process, assign its ProcessStartInfo and start it

                System.Diagnostics.Process proc = new System.Diagnostics.Process();

                proc.StartInfo = procStartInfo;

                proc.Start();

 

                // Get the output into a string

                string result = proc.StandardOutput.ReadToEnd();

 

                // Display the command output.

                Console.WriteLine(result);

            }

            catch (Exception objException)

            {

                // Log the exception

            }

        }

 

        /// <summary>

        /// Execute the command Asynchronously.

        /// </summary>

        /// <param name="command">string command.</param>

        public void ExecuteCommandAsync(string command)

        {

            try

            {

                //Asynchronously start the Thread to process the Execute command request.

                Thread objThread = new Thread(new ParameterizedThreadStart(ExecuteCommandSync));

                //Make the thread as background thread.

                objThread.IsBackground = true;

                //Set the Priority of the thread.

                objThread.Priority = ThreadPriority.AboveNormal;

                //Start the thread.

                objThread.Start(command);

            }

            catch (ThreadStartException objException)

            {

                // Log the exception

            }

            catch (ThreadAbortException objException)

            {

                // Log the exception

            }

            catch (Exception objException)

            {

                // Log the exception

            }

        }

        #endregion

    }

}