Click here to Skip to main content
Click here to Skip to main content

How to Execute a Command in C# ?

, 11 May 2008
Rate this:
Please Sign up or sign in to vote.
This article will help you to execute a command in C#, just like we execute a command using the Windows command prompt

Introduction

It is normal practice to open the Windows 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. 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…

Using the Code

The code given below creates a process i.e. a command process and then invokes 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 reference. 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. The code has enough comments, hence making it self-explanatory.

Below is the code to execute the command synchronously:

/// <span class="code-SummaryComment"><summary></span>
/// Executes a shell command synchronously.
/// <span class="code-SummaryComment"></summary></span>
/// <span class="code-SummaryComment"><param name="command">string command</param></span>
/// <span class="code-SummaryComment"><returns>string, as output of the command.</returns></span>
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
      }
}

The above code invokes the cmd process specifying the command to be executed. The option procStartInfo.RedirectStandardOutput is set to true, since we want the output to be redirected to the StreamReader. The procStartInfo.CreateNoWindow property is set to true, as we don't want the standard black window to appear. This will execute the command silently.

Below is the code to execute the command asynchronously:

/// <span class="code-SummaryComment"><summary></span>
/// Execute the command Asynchronously.
/// <span class="code-SummaryComment"></summary></span>
/// <span class="code-SummaryComment"><param name="command">string command.</param></span>
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
   }
}

If we observe carefully, the asynchronous execution of the command actually invokes the synchronous command execution method using a thread. The thread runs in the background making the command execution asynchronous in nature.

In the above execution sample, we find that there are two result sets of the command "dir". The first one appears immediately after the command and the second appears after the "Done!" statement. In this case, the first one is the synchronous execution of the command, which happens immediately and the second is the asynchronous execution of the "dir" command.

Points of Interest

I always thought of having some code that will execute my DOS commands, finally I had to build it.

You can find some more interesting stuff here.

History

  • 12th May, 2008: Initial post

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Author

Sandeep Aparajit
Software Developer
United States United States
Sandeep has 7+ yrs of IT experience. He is Microsoft Certified Technology Specialist and has been certified for Analyzing Requirements and Defining Microsoft .NET Solution Architectures.
He is an active member of:
1. MSDN Forums
2. CodeProject.com
3. Community-Credit.com
4. Blogspot.com
 
You can find his contributions at:
My Blog
Photography

Comments and Discussions

 
QuestionCannot read configuration file due to insufficient permissions. Pinmemberhernaldo.gonzalez28-May-14 10:52 
QuestionI have problem needs your help PinmemberMember 810758123-Jan-14 3:21 
GeneralMy vote of 5 Pinmember Gun Gun Febrianza29-May-13 6:55 
QuestionNot working :-( PinprofessionalAmogh Natu21-May-13 23:19 
GeneralMy vote of 5 PinmemberMember 83129214-Oct-12 2:06 
Question:) Pinmembernaymyohaen2-Jul-12 21:45 
GeneralMy vote of 5 PinmemberCarlos ABS11-Apr-12 2:54 
GeneralMy vote of 5 PinmemberMilton Rodríguez22-Nov-11 2:46 
QuestionWhat if i want a continues commands?? PinmemberRIKISH1-Nov-11 23:34 
Questionre:How to Execute a Command in C# ? Pinmemberhafizhanif31-Oct-11 20:26 
GeneralMy vote of 5 PinmemberIanJ196525-May-11 20:39 
GeneralMy vote of 1 PinmemberMember 775354214-Mar-11 9:11 
Process.Start() does NOT run commands synchronously. Your "sync code run" runs the command asynchronously!
GeneralMy vote of 5 Pinmemberbbakkebo2-Mar-11 3:56 
GeneralMy vote of 5 Pinmembercnndnmdfn31-Oct-10 22:28 
GeneralNeed to run asynchronously and capture output Pinmemberbrudog569-Jul-10 5:00 
GeneralMy vote of 2 PinmemberPriyank Bolia16-Mar-09 23:27 
Generalftp command line Pinmembermega1510-Jun-08 11:53 
GeneralRe: ftp command line Pinmemberneal12321-Jan-10 19:09 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

| Advertise | Privacy | Mobile
Web02 | 2.8.140721.1 | Last Updated 12 May 2008
Article Copyright 2008 by Sandeep Aparajit
Everything else Copyright © CodeProject, 1999-2014
Terms of Service
Layout: fixed | fluid